Monitoring Bird Populations

Abstracts from the 1998 NAOC Workshop

Titles & topics

• Are counts censuses?  Ruminations on the role of statisticians in a review of monitoring methods
• Breeding Bird Survey and other programs
• 'BirdSource' and the role of large-scale citizen efforts for monitoring winter bird populations
• Breeding ground populations
• A Comparison of Point Count Census Methods for Monitoring Landbirds
• Integrated Landbird Monitoring - the Canadian experience
• Integrated Population Monitoring of Terrestrial Breeding Birds- the UK Experience
• Mexican Perspective
• Migration Monitoring
• Monitoring activities in the American tropics
• Monitoring: Conservation science or chicken soup?
• Monitoring the distribution and abundance of the birds of North America
• Monitoring: how and why
• Monitoring North America's diurnal raptors: where we are and where we are going
• Monitoring Primary Demographic Parameters: the Maps and Bird Programs
• Monitoring seabird populations in Northeastern North America: a summary overview for the Atlantic seaboard
• Monitoring of wading birds in North America
• Partners in Flight Landbird Monitoring Strategy
• Seabird Monitoring Opportunities in the North Pacific: Status, Problems, and Opportunities
• Shorebird monitoring programs
• A conservation agency's perspective
• A panel discussion
• The Role of the National Wildlife Refuge System in Monitoring North American Bird Populations
• Winter Waterfowl Surveys - Current Programs and Needs for Improvement

Abstracts

Integrated Population Monitoring of Terrestrial Breeding Birds - the UK Experience  Stephen R Baillie  British Trust for Ornithology, The Nunnery, Thetford,  IP24 2PU, UK  email: stephen.baillie@bto.org

The BTO's IPM programme aims to alert conservation bodies to changes in numbers and vital rates requiring conservation action or further research. Demographic and environmental data are used to identify the life-cycle stages and environmental factors likely to be responsible for changes in numbers. The main volunteer-based schemes and what they measure are set out below.

Scheme	Started	Measures	Method
Breeding Bird Survey (BBS)	1994	Numbers Transect	counts
Common Birds Census (CBC)	1962	Numbers Mapping	censuses
Nest Record Scheme (NRS)	1932	Breeding performance	Record nest histories
Constant Effort Sites (CES)	1983	Numbers, Productivity, Survival	Standardised mist-netting, May - August
Retrapping Adults for Survival (RAS)	1998	Survival	Mark recapture/ resighting
Ringing and recoveries (RIN)	1909	Survival, Dispersal, Productivity	Collation of ringing and recovery data

Where possible we aim to use data derived from these schemes to build simple population dynamics models to test whether observed relationships between numbers, vital rates and environmental variables are sufficient to explain observed changes in numbers.

Breeding atlases undertaken every 20 years provide data on changes in the distributions of all species (and in future will also provide data on changes in numbers for most). The above annual monitoring schemes provide data on numbers, breeding success and survival for about 60 widespread species, and data on at least one of these for over 100 species. We lack good data on numbers of nesting attempts and on post-fledging survival for most species, although data on the proportions of juveniles in late summer compensate for this to some extent. There is some bias in geographic coverage related to the availability of observers. CES provides data on numbers, productivity and survival from the same sites but apart from this we do not generally gather data on numbers, productivity and survival from the same study areas.  We plan to promote further integrated site-based monitoring in the future. In addition to annual monitoring schemes we undertake surveys of particular species where more targeted coverage is needed or to address specific ecological questions. Most of these surveys use randomised study designs.

Most of our annual monitoring schemes are not based on randomised study designs. Nevertheless, validation studies of these schemes usually indicate that samples are representative and that common large-scale patterns are shown by different schemes. For example, population changes measured by the CBC and CES, schemes sampling different habitats with very different methods, are well correlated. In 1994 we introduced the BBS to increase the geographical, habitat and species coverage of our breeding bird monitoring, in addition to providing a more rigorous sampling framework. Over 2000 1km squares are sampled annually using line transects. The squares are selected randomly, with stratification by observer density. This allows us to improve precision in areas with more observers without introducing bias. To get the most out of ornithological monitoring we must undertake critical analyses of key long-term data sets while continuing to improve the collection of new data.

The IPM programme benefits from all the schemes being run by a single organisation, with schemes being lead by the scientists who are responsible for data analysis. Common coding systems for habitat and other data operate across schemes. Over 70% of CES data are submitted on disk and this approach is being extended to some other schemes. Rigorous statistical modelling using a range of techniques and software that has become available over the last 10 years is essential. Statistical and environmental expertise are important for the successful development of the IPM programme and we benefit from many collaborations in these areas. Some analyses are limited by the costs and difficulty of computerising historical data. Deliberate gaps in species coverage have also caused problems. For example, restrictions on the ringing of House Sparrows and Sand Martins during the 1970s have made it difficult to investigate subsequent population declines. Lack of data on key environmental variables, and particularly of time-series of such data, places more severe limits on what can be achieved. BBS is already collecting data on large-scale habitat change and in future we may seek to involve our volunteers in collecting other environmental data.

I will outline briefly some key examples of outputs from the BTO's IPM programme. Conservation alerts to population declines are being evaluated by measuring changes in numbers from smoothed population indices and comparing them with standard criteria based on declines of 50% (Red alert) and 25% (Amber alert) over 25 years. We have recently started to produce a regular report detailing trends in numbers and vital rates, together with alerts and interpretation. Modelling of census, nest records and ringing data for the Song Thrush, a rapidly declining farmland species, shows that the decline has been brought about mainly by a change in first year survival. The nest record scheme has shown highly significant trends towards earlier laying in a wide range of species. These trends may be linked to global warming.

Volunteers are the BTO's key resource and without them it would not be possible to carry out such extensive monitoring of bird populations in the UK. Most volunteers are highly skilled observers or ringers and are able to follow demanding recording and sampling protocols. Nevertheless volunteer-based approaches do involve some trade-off between data volume and rigour, and often have difficulty in covering remote areas. Many BTO projects are organised through a regional network of volunteer organisers. Successful schemes involve simple designs from the observers perspective, with clear instructions and recording forms. Pilot surveys are essential when setting up new projects. For randomised surveys of single species it may be possible to minimise observer dissatisfaction at not finding the target species by allowing regional organisers to make nil returns for totally unsuitable areas, stratifying by previous data on bird density (which may also increase precision) and including additional species. Good feedback is very important for maintaining the commitment of observers. Personal interactions with regional or national organisers, scheme newsletters, reports in semi-popular publications and meetings are all important components of this. Properly resourced support for volunteer networks is an essential part of the BTO's approach to bird monitoring, requiring scheme organisers with the skills required to lead, organise and motivate volunteers effectively.

The Partners in Flight Landbird Monitoring Strategy  Jonathan Bart, USGS, Boise State University, Boise ID 83706  (email: jbart@eagle.idbsu.edu)

In March, 1997 the Monitoring Working Group of Partners in Flight (PIF) agreed to revise the PIF Monitoring "Needs Assessment" published twice during the past decade.  The revision, to be called the "Partners in Flight Landbird Monitoring Strategy", will identify the most important improvements to make in landbird monitoring and will contain an implementation strategy, to be developed with agencies and other organizations involved in landbird monitoring.  Major sections of the report will include "Reasons for Monitoring Bird Populations", "Current Programs", "Needed Improvements", and "Implementation".  Authors for each section have been recruited and a 12-person committee to review suggestions for the Needed Improvements section has been appointed.  Partners in Flight expects to circulate a draft Strategy during the fall of 1998 and hopes to have the final version done by December  1998.

Monitoring North America's diurnal raptors: where we are and where we are going.  Keith L. Bildstein, Hawk Mountain Sanctuary, Kempton, PA 19529, and Steve Hoffman, HawkWatch International, Salt Lake City, UT.  (Email: Bildstein@hawkmountain.org)

North American diurnal raptors are secretive, wide-ranging, highly mobile birds whose populations can be both logistically difficult and financially prohibitive to survey and monitor.  A workshop attended by 35 raptor biologists in Boise, Idaho, in August 1996 initiated discussion on the development of monitoring strategies for 32 species of NA raptors, including the use of BBSs, CBCs, nest checks, roadside transects, roost counts, and migration counts.  The consensus was that one in three species is currently monitored adequately, and that migration counts may be able to monitor populations of 44% (14 of 32) the species considered.  Hawk Mountain Sanctuary has been conducting counts at its watchsite in eastern Pennsylvania since 1934.  HawkWatch International has been conducting counts at some of its 16 watch sites in Texas, New Mexico, Arizona, Utah, Nevada, Montana, Oregon, and Washington, since 1977.  The two organizations, together with Pronatura-Veracruz are working together at a count site in Veracruz, Mexico.  The Hawk Migration Association of North American has accumulated relatively standardized daily report forms from members working at more than 1700 sites (82% of which are east of the Mississippi), since 1974.  Thirty-nine of these sites have been collecting data for a decade or more.  Although the use of such data to indicate population trends is not without problems, and while statistical methodologies regarding their analyses continue to be modified, preliminary evaluations of the usefulness of migration counts for determining population trends are encouraging.  Properly collected and analyzed, such data can provide valuable information regarding population fluctuations in these species.

Winter Waterfowl Surveys - Current Programs and Needs for Improvement  Robert J. Blohm, Graham W. Smith, James D. Nichols, and David E. Sharp  U.S. Fish and Wildlife Service, Office of Migratory Bird Management, Washington D.C. 20240 and U.S.G.S. Patuxent Wildlife Research Center (JDN)

Since the mid-1930s, biologists have surveyed waterfowl on key wintering areas throughout the continent each year.  Until the development of the operational breeding ground survey in the mid-1950s, the results of these extensive surveys provided the primary basis for establishing annual waterfowl hunting regulations.  In total, the winter waterfowl survey program is comprised of a number of different cooperative survey activities, all of which are directed at gathering information on wintering stocks of waterfowl.  The cornerstone of this program is the Mid-winter Inventory that is currently conducted during the first full week of January, at a time when duck seasons are coming to a close, and waterfowl have generally completed fall migratory movements but are still concentrated.  Some of the other surveys that complement the Mid-winter Inventory are the Mexican Waterfowl Survey, Gulf Coast Redhead Survey, December/January Goose Surveys, Productivity Surveys, and the Sea Duck Survey, among many others.  Methodologies range from aerial cruise and transect surveys, to photographic surveys, to ground counts.  Many of the surveys lack statistical rigor, i.e., have weak survey designs or no measure of precision.  Common problems encompass observer visibility bias, inconsistent survey efforts, distributional shifts, and problematic survey design.  Yet, despite these shortcomings, these activities have over time provided researchers and managers with useful long-term information on general population trend, distribution, and habitat use for swans, many goose populations, and those duck species not adequately covered by systematic breeding ground surveys.  Periodic reviews of these inventories have focused on objectives, sources of bias and imprecision, and recommendations for improvement.  An outgrowth of these evaluations has been a focus on: (1) standardizing data collection procedures, (2) increasing availability of these data sets, (3) evaluating alternative methods of data analysis, and (4) considering alternative survey designs.  More recently, efforts are underway to begin integrating population trend and distribution information for wintering waterfowl with habitat data via GIS formats.  Finally, winter waterfowl inventories remain under close scrutiny today as continuing budget shortfalls, and downsizing and streamlining efforts within conservation agencies force the waterfowl management community to measure the benefits of maintaining longstanding data sets against the limitations of the surveys and changing priorities and needs within the migratory bird survey program.

Why Monitor Birds? A panel discussion  Michael Bradstreet, Executive Director  Bird Studies Canada/Long Point Bird Observatory  P.O. Box 160, Port Rowan, Ontario, Canada N0E 1M0  e-mail: mbradstreet@bsc-eoc.org

Canada is a large country with a small human population, mostly living within a few hundred miles of the US border.  Most bird species in Canada breed north of where most people live

Using GIS, BSC and CWS mapped the breeding and winter ranges of all landbird species breeding in Canada.  From these maps, 90 of 300 landbird species were determined to be of high Canadian responsibility, that is 60% or more of the species' North American range was in Canada.  Most such species nest in the swath of boreal, montane and mixed-wood forests that cross Canada in a huge arc, and most of these species winter outside Canada.  Given that BBS coverage in Canada is poor, because the people and therefore the roads do not extend far north, other methods of tracking population change in species of high Canadian responsibility are essential.   Canada has become a leader in developing methods for using counts of migrants to track population changes.

Most of the development and application of these methodologies has occurred at Long Point Bird Observatory, on the north shore of Lake Erie.  LPBO now produces annual indices of abundance for about 65 common spring and fall migrants, and has determined to a reasonable degree that trends in these annual indices reflect population changes.  Bird Studies Canada is now helping to establish a network of stations across Canada, called the Canadian Migration Monitoring Network, and our hope is that analysis of such data will give us an economic and  reasonable picture of population changes in landbird species in the northern reaches of the continent.

Breeding Ground Populations  Canadian Wildlife Service Participants for Presentation:  Dale Caswell, Prairie and Northern Region  Kathryn Dickson, Headquarters  Andre Breault, Pacific and Yukon Region  Myrtle Bateman, Atlantic Region  Daniel Bordage, Quebec Region  Ken Ross, Ontario Region

 Because waterfowl are hunted, their population status has been evaluated for nearly half a century.  This presentation describes the types of waterfowl monitoring programs that are in place mainly on the breeding grounds in Canada, when these programs began, how they evolved, and the extent of their geographic coverage.  Details on methods or results are not included but instead some examples are given.  As most waterfowl populations are shared provincially, nationally, and internationally, the majority of the programs are conducted cooperatively among the Canadian Wildlife Service, U.S. Fish and Wildlife Service, provincial and territorial agencies, and state agencies, as well as some nongovernmental organizations.  Monitoring programs include surveys on the breeding, migration, and staging areas although the breeding are programs are emphasized here.  Special research programs are designed to elucidate the causes in population change.  Despite the participation of a large number of partners and the size of the programs already in place, there remain important gaps in our knowledge and many opportunities to modify and improve the monitoring program.

Ducks   In Canada, the majority of the surveys for duck population trends are conducted on the breeding grounds but some are carried out on important staging areas.  The grasslands and parklands of Prairie Canada support the largest breeding populations of ducks in Canada and because of the significance of its contribution to the continental duck population, this region has been subject to long term monitoring.  Experimental aerial surveys to estimate the size of breeding populations were conducted by the USFWS in 1947 and became operational in 1955.  Aerial surveys are biased due to species differences in visibility and effects of vegetation on numbers observed. Concurrent ground surveys to provide correction factors for visibility bias were initiated in 1961.  Canadian Wildlife Service took over coordination of the ground portion of the survey in 1973.  by the late 1970s, the ground transects were moved on to the flight lines to improve the survey design. In addition, by the 1980s, the ground portion of the May Breeding Population survey was expanded to include information to monitor the habitat conditions of the wetland basins and surrounding uplands.  In the 1980s, the numbers of air ground transects increase in response to broadening the information base during the period of "Stabilized Regulations."  In 1990 and 1991, the number of air ground was doubled to improve the precision about the population estimates as a method of improving the ability to monitor the success of the implementation of the Prairie Habitat Joint Venture (PHJV) under the North American Waterfowl Management Plan (NAWMP).  During this period, new protocols were developed and put in place to calculate the visibility rates for each species and crew area.   In contrast to the Prairies population trends of breeding ducks in Eastern Canada, British Columbia and Southern Yukon have traditionally been less well-studied.  Surveys have been initiated to monitor various sub-populations across the breeding range. A ground survey was initiated in the interior grasslands of British Columbia in 1987, and a ground survey in Southern Yukon began in 1992.  There has been a historical database dating back to the 1950s and 1960s for ducks in Eastern Canada but it has not been consistent.  Ground surveys, which are conducted every 3-4 years, were established in Southern Ontario in 1971.  Aerial surveys in northern Ontario have been conducted since 1980.  In the Atlantic region, various surveys have been conducted since the 1950s and have increased in consistency with time.   The formation of the Black Duck Joint Venture (BDJV) renewed an interest in monitoring eastern duck populations.  One of the objectives of the BDJV was to monitor the size of the breeding populations and thus, resources have been made available since 1990 to conduct annual surveys. The survey was designed to provide population estimates primarily for Black duck and Mallards and uses a variety of techniques from fixed wing transect surveys in the southern areas, helicopter plots in the forested northern areas, to ground surveys on Prince Edward Island.

Geese   There has been a concerted effort to monitor breeding populations of geese from a breeding ground perspective whenever and wherever feasible.  An aerial photographic inventory of Lesser Snow Goose and Ross Goose breeding colonies was initiated in 1972 and was designed to be conducted on a rotational basis throughout the colonies every five years.  The projected cycle, especially for the eastern high arctic colonies, was not obtained as illustrated by Baffin and Southampton Islands which were surveyed in 1973, 1979, and again finally in 1997.

An index to breeding success in the Arctic, habitat conditions, and goose nesting phenology has been evaluated at selected sites in the higher arctic using an aerial recognizance survey during the period of 1988 through 1994.  There was an experimental component to estimate breeding population size at some specific areas in the eastern arctic such as the Great Plain of the Kojduak on Baffin Island.  Other multispecies population surveys sponsored by the Arctic Goose Joint Venture (AGJV) and land claims agreements are being tested and are in various stages of development.  These are not yet considered as consistent monitoring activities but are currently testing experimental designs and providing baseline data for future monitoring programs.

Through cooperative programs with the federal agencies, and states and provinces of the Mississippi and Atlantic flyways, breeding population surveys for the sub arctic interior populations of Canada Geese were initiated.  These aerial transect surveys have been established for several years for the Eastern Prairie and the Mississippi valley populations of Canada Geese.  More recently, survey of similar design have been initiated for the Southern James Bay and the Atlantic populations of Canada Geese.   Dramatic increases in some southern populations of large Canada Geese have also increased the need for population estimates as it has confounded the information required in the overall management of Canada Geese.  For some of the breeding ground components, stratified ground surveys and/or aerial surveys have been designed and established to monitor the size and eventual status of these populations of "resident" Canada Geese.

Future  Although there has been a lot of activity for a long time by a multitude of agencies on waterfowl, there is still room for improvement.  There are still many areas and many species that are not being monitored to the extent that managers would prefer and the demand to improve the situation are increasing as the management of waterfowl populations becomes more complex or more scientific.  As more population and species models under Adaptive Harvest Management (AHM) are developed, more precise estimates of the associated breeding populations will be required as a monitoring tool in the success of AHM.

At the same time, we are being asked to provide research and management information for wildlife at the ecosystem or ecozone levels.  This is resulting in additional demands being placed on our existing datasets to answer questions that they were not originally designed to address.  Waterfowl managers are being asked to adjust, redesign, or modify existing survey programs to become more efficient in terms of cost and broader in terms of species and areas while, at the same time, maintaining the integrity of the original design to provide the required information on the annual status on these species and the result of management actions on these hunted populations.   We have learned from experience that long gaps in monitoring the status of the high arctic populations is not in the best scientific or public interest to waterfowl management.  We need to maintain consistent information but, at the same time, deal with decreasing budgets.  The high cost of doing business in the Arctic is placing more pressure on managers to broaden the emphasis of these waterfowl programs to become more multispecies and multipurpose in nature.

Monitoring Primary Demographic Parameters:  The MAPS and BBIRD Programs  David F. DeSante, Institute for Bird Populations, P.O.Box 1346, Point Reyes Station, CA 94956  Thomas E. Martin, University of Montana, Missoula, Montana

Monitoring primary demographic parameters (productivity and survivorship) is a critically important component of any integrated avian population monitoring strategy that aims to determine the proximal demographic causes of population change, identify conservation strategies and management actions to reverse population declines, and evaluate the effectiveness of the conservation strategies and management actions implemented.  This is because environmental stressors and management actions affect primary demographic parameters directly and without the buffering or time lags that often occur with secondary population trends.  Furthermore, primary demographic parameters provide crucial information about the stage of the life cycle at which population change is effected and critical information about the health of populations.  Moreover, primary demographic parameters provide a clear index of the quality of habitats and landscapes and allow identification of habitat conditions that provide source populations and that influence sink populations.

In North America, different aspects of productivity are monitored at different, but overlapping, spatial scales by the Monitoring Avian Productivity and Survivorship (MAPS) and the Breeding Biology Research and Monitoring Database (BBIRD) programs; survivorship, however, is monitored only by MAPS.   The MAPS program is a continent-wide, cooperative network of over 430 (in 1997) constant-effort mist-netting stations operated during the breeding season that provides indices and estimates of adult population size, indices of post- fledging productivity, and estimates of adult survival rate and recruitment into the adult population for a suite of over 100 target species.  MAPS aims to describe: (1) temporal and spatial patterns in productivity and survivorship at multiple spatial scales ranging from the local landscape to the entire continent; and (2)relationships between those patterns and (a) ecological characteristics of the target species, (b) population trends of the target species, (c) landscape-level habitat characteristics, and (d) weather variables.  Temporal and spatial variation in productivity indices are modelled with logistic regression while such variation in survivorship is modelled through modified Cormack-Jolly- Seber mark-recapture analyses.  Model selection is conducted using AIC.  The potential weaknesses of MAPS are that: (1) the adequacy of the productivity indices is unknown because the populations sampled are not clearly identified and the indices could be affected by variation in dispersal as well as productivity; (2) inferences at larger spatial scales may not be reliable beyond the sample of stations because of the lack of a probability-based sampling strategy; and (3) large-scale indices and estimates may be biased when substantial smaller-scale variation occurs, while more accurate smaller-scale indices and estimates may have limited precision unless relatively large numbers of birds are sampled.

Patterns of MAPS productivity indices with respect to nest location and migration strategy agree with those found by direct nest monitoring and those predicted from theoreticalconsiderations.  In addition, these patterns are consistent over both time and space, and were similar for eastern North America whether data were included only from the 61 stations that were operated during each of the four pilot years or from all stations operated each year which increased nearly threefold between 1992 and 1995 from 81 to 203 stations.  Survival-rateestimates as a function of migration strategy vary inversely with productivity indices, again in agreement with current life-history theory.   Moreover, annual productivity indices from population-wide mist netting in Kirtland's Warblers have been found to correlate well with productivity estimated from annual changes in population size and survival rates.  Finally, spatial differences in productivity indices and/or survival-rate estimates detected through model selection by AIC are consistent with and can account for spatial differences in population trends as detected from short-term MAPS data or longer-term BBS data for many species at multiple spatial scales (ranging from clusters of stations in single national parks or national forests to major portions of the continent).  These results suggest that the potential weaknesses of MAPS enumerated above do not preclude the program from providing critically useful information regarding temporal and spatial patterns of productivity and survivorship at multiple spatial scales.  The next step is to include landscape- level habitat data into multivariate models of productivity and survivorship.

BBIRD is a continent-wide collaborative program that provides standardized field methodologies for studying nesting success in birds.  BBIRD monitors nesting success (clutch size, Mayfield egg and nestling survival rates, number fledged), nesting habitat, and, depending upon individual collaborators' interest, specific treatment effects (e.g., forestry practices, grazing regimes, landscape variation) through direct nest and vegetation monitoring. Studies at local sites are administrated by independent investigators to maintain high data quality.

BBIRD includes several spatial scales: the nest site, which includes a 5-m radius nested within an11.3-m sampling radius; the plot, typically about 30- 50 ha; the site, which includes 4-30 plots and may include different treatments; and the landscape, currently measured at a 10-km scale.  Point counts are used to index population size at plots.  Standardized vegetation sampling is conducted at nest sites, at 3 points within point counts (to provide a random sample), and where individual investigators deem useful at "non-use" sites that are paired with locations of actual nests.  BBIRD currently includes data from 27 sites, 360 plots, and >3000 nests of more than 200 bird species.  BBIRD aims to identify causes of variation in nesting success in non-game birds in multiple habitats throughout North America, determine habitat requirements for viable populations, identify links between population viability and habitat features at multiple spatial scales (nest, plot, ite, landscape, region), and rovide spatial and temporal baseline monitoring data at the specific habitat and local landscape scale to allow early identification of demographic problems.  The potential weaknesses of BBIRD are that: (1) nesting success is only an index of annual reproductive success (unless birds are individually color-marked, all nesting attempts are monitored, and the fateof fledglings are followed until they reach independence from their parents); (2) large sample sizes are difficult to obtain for some species groups (i.e., forest canopy nesters); and (3) the assignment of correct nest fate includes some uncertainty.

Recent analyses of BBIRD data provide important insight into landscape-level effects of forest coverage on rates of cowbird brood parasitism and rates of nest predation.  The percent ofthe landscape (measured at 10 km radius) that is in forest cover has a strong influence on Brown-headed Cowbird parasitism rate as previously documented by others. However, the analyses show that the slope of the relationship (the strength of the response of cowbirds to changes in forest cover) varies strongly among eastern, midwestern, and western regions of  the U.S.  In contrast, nest predation does not vary with forest cover in the landscape, at least at the scale and resolution currently being measured (finer resolution studies are planned).  Regardless of the resolution, the results indicate that effects of landscape-level loss of forest on nest predation are not strong.  Previous individual studies have often been based on artificial nests, which include many biases, and may often be measuring edge effects rather than landscape effects based on their designs.  The BBIRD program allows true replication at the landscape scale.

It is clear that MAPS and BBIRD provide complementary information about productivity in landbirds.  The two programs focus on different aspects and emphasize different, but overlapping, spatial scales.  Moreover, the strengths of each program tend somewhat to address the weaknesses of the other.  We suggest that both programs are necessary to provide a comprehensive monitoring of all aspects of productivity.  We also suggest that a hypothesis-driven sampling strategy, based on BBS population trends at the physiographic stratum scale, that monitors both productivity and survivorship using MAPS and BBIRD techniques may provide an optimal experimental design for an integrated monitoring effort to investigate causes of population declines.

Integrated Landbird Monitoring - the Canadian Experience  C.M. Downes  National Wildlife Research Centre  Canadian Wildlife Service  Hull, Quebec, K1A 0H3, CANADA  Connie.Downes@ec.gc.ca

The Canadian Landbird Monitoring Strategy (CLMS) was published in 1994 by the Canadian Wildlife Service, as one of the first products of Partners in Flight Canada. The CLMS provides a framework to integrate monitoring activities that are conducted by  both government and conservation organizations, and recommends a suite of surveys selected to provide data on the population status of landbirds in Canada. The CLMS concentrates on national or regional, multi-species monitoring programs aimed at tracking changes in species distribution and abundance.  Programs for monitoring other aspects of landbird population dynamics (e.g. productivity and survival) are also included.

In 1994  the selection of surveys for inclusion in the CLMS and the identification of data gaps was based on the mainly qualitative evaluations available at that time.  Much progress has been made since.  More rigorous evaluations of several surveys have been completed or are in progress and new surveys have started.  A priority-setting scheme for bird conservation and monitoring has been developed (Dunn, 1997).  This year the CLMS is being revised.  The priority-setting scheme will be used as a basis for identifying species for which Canada has the highest supervisory responsibility and those with inadequate monitoring information, and to focus efforts to improve monitoring coverage.  The surveys included in the current Monitoring Strategy will be re-evaluated and new surveys and techniques will be assessed.

Much work remains to be done.  While local surveys have recently started to cover nocturnal and marshland birds there is no coordinated effort to monitor these species at the national level.  There are still gaps in monitoring coverage of some northern species.  More coordination of expanding surveys, such as Checklists, is needed both at the national and continental level to ensure that there is consistency in data collection techniques and that needs of local  programs are being met.  Guidelines for land managers interested in monitoring specific sites should encourage data collection and storage techniques consistent with national guidelines and ensure that data from local monitoring programs can be integrated with, and complement regional and national systems.

The CLMS approach has been successful in encouraging increased volunteer participation in surveys and improved species and geographic coverage. However, because of the immense size and remoteness of much of Canada, volunteer-based monitoring will continue to be a challenge.  It is important to provide more opportunities for training and to raise public awareness within the birding community of the connection between monitoring and bird conservation and the continuing need for skilled participants in monitoring programs.

MIgration Monitoring  Erica Dunn, Canadian Wildlife Service, 100 Gamelin Blvd., Hull, Quebec, Canada K1A 0H3  David Hussell, Ministry of Natural Resources, 300 Water Street, Peterborough, ON, Canada K9J 8M5

 Migration Monitoring is the use of daily counts of migrants over or past a specific small area, for the use of population monitoring.  The method is ideal for diurnally-migrating raptors or waterfowl streaming past a lookout, but is also suitable for nocturnal migrants counted during stopover as long as most individuals leave after a single day's rest.

 Although in its infancy as an organized continental-scale monitoring program, there is some administrative structure in place.  A North American Migration Monitoring Council, with representatives from U.S. and Canadian governments and NGOs, has overseen preparation of standards for operation of stations that primarily monitor small landbirds (Hussell and Ralph 1995). Raptor counting is not currently represented on the Council but coordination of efforts is a goal.

 A Canadian Migration Monitoring Network is currently being formalized, under the direction of Bird Studies Canada (BSC).  Member stations will (among other things) adhere to the Hussell and Ralph (1995) guidelines, agree to cover 75% of the migration period of at least 5 target species (see partial list below), and contribute data to BSC in a standard format by an annual deadline.  BSC will archive data and analyse it using standard methods to ensure comparability of results, and both parties agree to data-sharing guidelines.  Improved communication and training are both goals and benefits of network membership.

 Migration counting as a means of monitoring populations was the subject of a major review (Dunn and Hussell 1995) which examined underlying assumptions, probable biases and sources of error, strengths and weaknesses of the program and prospects for its future as a major  monitoring program.  This and other work (Dunn et al. 1997) showed that migration count trends agreed well with BBS trends.

Major strengths of migration monitoring:  1.  Covers set of species otherwise poorly monitored and provides independent trend data for many others (see below).  2.  Evaluation and validation of method have been addressed.  3.  Analysis methods have been developed to cope with major sources of noise in the data (e.g. weather).  4.  Program can build on existing pool of stations and trained volunteers.

Major limitations of migration monitoring:  1.  Data are noisy.  (Of birds available to be counted each day, proportion actually counted may vary.  Also, the number of birds available to be counted is undoubtedly not a constant proportion of the numbers actually flying over in a 24-hr period, primarily due to weather  effects.)  2.  Data from distant stations cannot justifiably be pooled to derive regional trends (because it is not known whether 2 stations are sampling the same population or not; and abundance of birds at each station is not reliably proportional to the size of the population being monitored).  Instead we have to look for geographic patterns in trends from individual stations.  3.  Origin/destination of migrants counted at a given site are almost always unknown.  Therefore trends from a particular site cannot be used to justify conservation action in a particular breeding/wintering area. We can only look for geographic patterns in trends from individual  stations and consider whether a species is experiencing population change over a broad portion of its range.  4.  Habitat succession is a problem insofar as it causes long-term change in the migration counts (e.g. lower netting totals as vegetation grows taller).  Judicious choice of count sites and habitat management are important issues.  5.  Stations are labour intensive and relatively expensive (although possibly comparable to other surveys given breadth of bird's range being sampled).  6.  Desirable geographic coverage not always achievable, because of limits to where sustainable stations can be sited.

Priorities for future development of a formalized migration monitoring  program:  1.  Further develop network(s).  All stations wishing to contribute should agree to common standards and protocols.  If there is more than one network these should be coordinated through the Migration Monitoring Council to ensure compatibility of data and results.  2.  Further evaluation needed of:   a.  Ability of individual stations to detect trends which agree with those from independent  sources,   b.  Effectiveness of sharing daily coverage among several stations in the same local area.  3.  Research in areas that could add value to migration monitoring:   a.  Ways to identify source/destination of migrants at a given site (e.g. DNA, isotope  ratios, radio transmitters),   b.  Improved radar/acoustic means of counting migrants (to evaluate variation of what is  counted vs. what passes by uncounted),   c.  Investigation of accuracy of productivity indices derived from fall age ratios of  migrants,   d.  Improvements to analysis procedures.  4.  Develop stable funding for at least one scientist and one data technician to handle data centrally and analyze trends.

References:  Dunn, E.H., and D.J.T. Hussell. 1995. Using migration counts to monitor landbird populations:  review and evaluation of current status. Pp. 43-88  In: Power, Dennis M. (Ed.) Current  Ornithology, Vol. 12.  Plenum Press, New York.  Dunn, E.H., D.J. T. Hussell and R.J. Adams. 1997. Monitoring songbird population change with  autumn mist-netting. J. Wildl. Manage. 61:389-396.  Hussell, D.J.T., and C.J. Ralph. 1995. Recommended methods for monitoring bird populations by  counting and banding migrants. (http://www.rsl.psw.fs.fed.us/pif/int_prot.html)

Appendix I:  Target species for migration monitoring in North America

Group A:  20 species with <50% of Canadian/U.S. breeding range covered  by BBS and <60% of wintering range in Canada/U.S.

Alder Flycatcher  Lincoln's Sparrow  Swainson's Thrush  American Pipit  Magnolia Warbler  Tennessee Warbler  Bay-breasted Warbler  Merlin  White-winged Crossbill  Blackpoll Warbler  Northern Waterthrush  Wilson's Warbler  Cape May Warbler  Orange-crowned Warbler  Yellow-bellied Flycatcher  Connecticut Warbler  Osprey  Yellow-bellied Sapsucker  Gray-cheeked Thrush  Savannah Sparrow

Group B:  30 species with <50% of Canadian/U.S. breeding range covered  by BBS and >60% of wintering range in Canada/U.S.

Group C:  44 species with <50% of Canadian/Alaskan breeding range  covered by BBS and <60% of wintering range in Canada/U.S.

Group D:  28 species with <50% of Canadian/Alaskan breeding range  covered by BBS and >60% of wintering range in Canada/U.S.

Monitoring of Wading Birds in North America  R. Michael Erwin and Robert W. Butler, USGS Patuxent Wildlife Research Center and Department of Environmental Sciences, University of Virginia, Charlottesville VA 22903 USA and Canadian Wildlife Service-Environment Canada, 5421 Robertson Rd, RR 1, Delta, BC Canada V4K 3Y3.  (Email: rme5g@virginia.edu and Rob.Butler@ec.gc.ca)

Monitoring of wading birds is historically one of the oldest bird conservation programs in North America; the millinery trade in the late 1800s nearly extirpated a number of species, especially egrets, resulting in efforts by the National Audubon Society to protect nesting colonies.  Currently, there are a modest number of species (n=29), families (n=4) and orders (n=2) in North America, with 18 species being found north of Mexico.  Except for the Great Blue Heron (Ardea herodias) which is moderately well covered by the BBS in the U.S.,  and by a national monitoring program in Canada (but not in Mexico), no other species are well monitored on a national level.  At regional levels, some monitoring efforts are made for species of concern such as Black-crowned Night-Herons (Nycticorax nycticorax), Wood Storks (Mycteria americana), White Ibis (Eudocimus albus), and White-faced Ibis (Plegadis chihi), but much of the effort is fractionated and inconsistent and is not driven by an overall comprehensive plan. In Mexico, wading bird monitoring is limited to a few key wetland areas (e.g. Laguna de Terminos and Sian Kaan Reserve in the Yucatan) or key species such as the Greater Flamingo (Phoenicopterus ruber).  Even for species where there is evidence of declines such as the IUCN-listed Agami Heron (Agamia agamia) and Fasciated Tiger Heron (Tigrisoma fasciatum) in Mexico, the Reddish Egret (Egretta rufescens) along the Gulf Coast of the U.S., and the American Bittern (Botaurus lentiginosus) and Least Bittern (Ixobrychus exilis) throughout North America, little monitoring effort exists.  The U.S. Geological Survey's Biological Resources Division is currently developing  a national colonial waterbird inventory and monitoring starting with monitoring data collected by the Atlantic coastal states in the early 1990s.  This effort will depend on states providing monitoring data but then archiving the data in a national database, similar to the earlier efforts of the Colonial Bird Register supported by the National Audubon Society.

Preliminary evaluation of the regional and national monitoring efforts indicated that the major weaknesses include: (1) first, and most importantly, lack of an overall comprehensive waterbird conservation plan for North America that could be subsumed within the North American Waterfowl Managment Plan (the first meeting of such an effort however is scheduled for April 1998); (2) related to (1) above, a lack of consistent program support at state, regional/provincial, or national levels for funding and manpower; (3) clearly identifying the questions of interest and following a statistically rigorous protocol for colony surveys and for estimating populations; (4) need for training programs for observers; (5) incorporating into population estimation activities an effort to collect demographic, habitat, contaminant, or other type of "bioassay" data that may serve a "bioindicator" function of the environment in addition to providing more insights into population or community condition; (6) the need for expanded geographic coverage (especially Mexico and Gulf Coast of the U.S.) and taxonomic coverage to include species such as the bitterns, Reddish Egret, Agami and Fasciated Tiger herons whose populations may be at risk, and (7) an almost complete lack of any monitoring efforts during migration or wintering periods.

Use of wading bird monitoring data has been primarily by state or federal agencies, mostly using nesting colony location data for regulatory purposes.  Relatively few attempts have been made to assess population trends at regional or national levels using nationally archived databases.  State efforts to assess trends have typically assumed that the entire population has been "counted" and therefore trends can be determined by simple comparisons over time of absolute numbers.  However, assumptions need to be tested to determine if: (1) all colonies of a species in a given region (state) have been located, and (2) counts made by different observers at each colony are comparable and accurately reflect the "true population" (e.g. total nest count) or whether several biases in sampling exist.

It is revealing that since the early 1900s when legal protection and refuge establishment by the Department of the Interior and National Audubon Society  led to heightened public interest and  population recoveries of most wading bird species, that apathy concerning population changes  seems to have set in over the past two decades - in spite of apparent declines in many states/provinces of two species of ibises, Snowy Egrets (Egretta thula),  Wood Storks, bitterns and the Mexican Agami and Fasciated Tiger herons.  However, we have learned hard lessons from endangered species programs that waiting too long on the population decline trajectory may be a costly if not irreversible error.  We need to act now before we experience another era when the Florida Everglades, Usumacinta Delta in Mexico, or Laguna Atascosa in Texas are totally devoid of spectacular wading bird flocks.

North American Bird Monitoring Workshop: Mexican Perspective  Patricia Escalante, Instituto de Biolog a UNAM, Mexico City, Mexico  (email: escalant@servidor.unam.mx)

 Mexico does not have a bird monitoring program at the national level, but ornithology in Mexico has developed significantly in the past five years and the possibility to establish an effort at this level is very good.  There are two main problems for a program like this.  The first is that more training is needed.  Simply bird identification workshops, sessions, or field trips are needed in which mixed groups share skills and help Mexican students in developing their identification skills. In Oaxaca, for instance,  one US professor studying the bird knowledge of Indian cultures (Dr. Eugene Hunn) was able to establish a local group who is every year doing the Christmas bird counts and they won the second place in Mexico for the richest count. Very little interaction takes place between foreign birdwatchers that come or live in Mexico and Mexicans.  Of course, these foreigners are contributing with information about bird populations on their own, and here we have the second main problem for a monitoring program that is communication. The organization of this kind of data in a way that it is current, together, and available. With the recent advances in communications this is not any more a very difficult task.

In this paper I will present the list of monitoring efforts going on in Mexico that very little is known about. These are the result from an electronic questionnaire sent to all members of CIPAMEX, an organization devoted to bird conservation in Mexico, active since 1992. All those who answered the questionnaire are willing to put their data in a central atabase, and INE-SEMARNAP had shown interest in funding the creation of this database and its establishment in a gopher or the internet. If this is developed, it is likely that the amount of data will grow, since CIPAMEX has now 120 active members, the majority of whom study birds in the field.

Regarding seabirds, the Pacific Seabird Group has a Standing Committee on Seabird Monitoring who is compiling information about this group in Mexico. It is not yet a monitoring program, but an inventory of the information at hand. It is composed of four databases (species, citations, personal data, and specific data by informant -species, localities, parameters, years of study, and comments). The coordinators is Eduardo Palacios of UC - Davis (epalacios@ucdavis.edu).  Although the list here is not exhaustive it helps in seeing where there are more monitoring efforts being taken place in the country. In the north there is only one effort in Chihuahua regarding landbirds, the central and southeastern part of the country are somewhat better represented.

The research projects listed in this study were provided by 19 people and include 29 projects. Most of this projects are more than one year surveys, with a maximum of 9-year study almost with the same methodology in the case of the Manantlan reserve study. Projects that had started since 1987  is 1 (the aquatic birds of the Yucatan Peninsula), 1988 is 1, 1989 is1, 1992 is 1, 1993 are 3, 1994 are 6, 1995 are 2, 1996 are 4, and 1997 are 4.  Although not at national scale, these projects provide the basis for national monitoring program, and most of them share in general similar methodology. The undertaking of this national program seems feasible and will follow these steps:  1) organizing the information being produced in databases with recognition to the producers  2) adopting a standard methodology  3) applying for funding for the operation of a central database that updates the information

'BirdSource' and the role of large-scale citizen efforts for monitoring winter bird populations.  John W. Fitzpatrick, Cornell Lab of Ornithology, Ithaca, NY 14850 (jwf7@cornell.edu  Frank Gill, National Audubon Society, New York, NY 10003 (fgill@audubon.org).

We introduce the group to 'BirdSource,' an interactive web-site designed to receive, archive, display, and interpret large-scale data bases on bird populations. Data are collected and submitted over the web by citizens, and screened for accuracy by several means including client-side software (JavaScript). Data are displayed in graphic and map formats prompted by user-generated queries. Links are provided to other important monitoring projects (e.g. BBS). Data bases from Christmas Bird Count (1900-1997) and Project FeederWatch (1988-1997) are being loaded now. Additional wintertime censusing projects include the Winter Finch Survey and the Great '98  Backyard Bird Count. Citizen-based data have enormous power to document local and regional population trends, year-to-year population fluctuations, and the effects of variation in landscape structure. Populations of many North American birds that winter in southern United States are declining. For this reason, and because many species numbers may be limited more on wintering grounds than on breeding grounds, large-scale citizen science projects during the winter represent an extremely important component to the national effort to monitor the continent's bird populations. We still are only scratching the surface of what can be accomplished in this  emerging scientific arena.

Why Monitor Birds? Point/Counterpoint.  The Role of the National Wildlife Refuge System in Monitoring North American Bird Populations  US Fish & Wildlife Service  Kathy Granillo, Regional Biologist  Refuges & Wildlife, Southwest Region

The Refuge System is clearly mandated to monitor the status and trends of fish, wildlife and plants in several laws that address refuge management and the US Fish and Wildlife Service as well as in the recent National Wildlife Refuge System Improvement Act of 1997. This new Act will be stepped down into policy and practice and will be codified in the Federal Register by October 1999.  Many far-reaching problems need to be addressed between now and then.

The lack of clear and consistent goals and objectives at the international, landscape, regional, and local level make it impossible to plan refuge activities across the System that consistently support critical wildlife resource needs of the larger landscape.  Refuge planning often focuses on the highest and best use of a refuge from a local perspective, rather than in the context of ecosystem, landscape, flyway, and national goals. The Service and the Refuge System need to identify strategies by which resource needs at these various levels can be stepped down so that refuges are managed for their highest and best use, while still complying with individual refuge purposes.

Approaches to inventory and monitoring on refuges are not consistent across regions, landscapes, or  ecosystems.  The contribution of a refuge to the larger landscape level is not often understood.  Inadequate baseline (inventories) data exists for most refuges.  As a result, management is often implemented without knowledge of existing resources and the potential negative or positive impact that may occur.  Monitoring associated with management practices is often inconsistent, not focused on target resources, or nonexistent.  Except for a few national surveys, standard protocols for inventorying and monitoring, when appropriate, are seldom used.  The System has not yet effectively utilized data bases to store and analyze basic inventory and monitoring data to evaluate management practices on refuges.  GIS technology and other standards have not been consistently implemented on refuges to produce resource mapping data compatible across refuges, regions, and other land management agencies.

For trend monitoring purposes, refuge efforts are most effectively focused on supporting coordinated national and regional monitoring programs.  But refuge lands do provide a unique opportunity to contribute to our understanding of species occurrence and distribution; to examine species and habitat relationships at the community or species level; and to conduct more intensive monitoring efforts focused on selected population parameters such as productivity and survivorship.

Shorebird monitoring programs.  Brian Harrington, Robert Gill, Cheri Gratto-Trevor, R. I. G. Morrison, and Gary Page.

Existing shorebird monitoring programs are reviewed with a view to describing their strengths and weaknesses for monitoring population change in shorebirds, and to consider how existing and/or additional survey might strengthen population trend monitoring.  The goal of the exercise is to begin identifying some of the considerations that should be evaluated in  deciding whether/how to improve population trend monitoring of North American shorebirds, and to consider opportunities on a species-by-species basis.

Seabird Monitoring in the North Pacific:  Status, Problems, and Opportunities  Scott A. Hatch1, G. Vernon Byrd2, William J. Sydeman3, and Charla M. Sterne1

Seabird monitoring is the accumulation of time series data on any aspect of seabird distribution, abundance, demography, or behavior.  Typical studies include annual or less frequent measures of numbers or productivity; less commonly, the focus is on marine habitat use, nesting chronology, food habits, survival (as in mark-resighting studies), or mortality (as in beached bird surveys).  The key requirement is that observations are replicated over time and are made with sufficient precision and accuracy to permit the meaningful analysis of variability and trends.

The value of monitoring seabirds is twofold.  On one hand, wildlife managers and the public are concerned about the welfare of particular species and populations that may be affected by human use of coastal lands and marine resources.  But seabirds also serve an important role as indicators of change in their marine environments.  For instance, some species respond dramatically to El Nino events, and that is only one well-studied example of the kinds of large-scale oceanographic and atomospheric processes to which seabirds are sensitive.  This characteristic increases the relevance of seabird monitoring during an era when global climate change is a growing concern.  Similarly, fishery managers are realizing that seabirds can serve as cost-effective samplers of young year classes of commercial fish stocks, which are otherwise difficult to assess.

Along the Pacific coast of North America, seabird monitoring has consumed substantial amounts of public funding since the early 1970's.  The effort stems from various legislatitve and executive mandates and has been largely uncoordinated among the many entities involved, including state, provincial, and federal agencies, non-governmental organizations, university faculty, and students.  While national and international investment in seabird monitoring is increasing, a recent survey of seabird monitoring effort conducted by the Pacific Seabird Group revealed that a vast amount of information already exists on the population parameters of Pacific seabirds.  New efforts are coming on line, particularly on the Asian side of the North Pacific, and additional data are accumulating steadily.  However, lack of ready access to this information, by resource managers and researchers alike, has been a continuing problem.  Much of the information is never published in the open literature, or publication lags far behind the gathering of data.

Currently, a collaborative effort by the U.S. Geological Survey and Pacific Seabird Group is producing a comprehensive database on seabird monitoring results from throughout the North Pacific.  The Pacific Seabird Monitoring Database presently contains more than 11,000 observations, each representing an annual measure of some population parameter (e.g., numbers, productivity, survival, breeding chronology, or other) for a given species, location, and year.  Those observations comprise about 1,800 time series spanning 1 to 37 years since studies were initiated.  Some quantity of information is available on 54 species breeding in 190 different locations.  Most of this work (82%) has been sponsored by Federal agencies in the United States, but significant contributions have also been made by private (12%), State (5%), and Provincial (1%) agencies.  Much work remains to be done to ensure the completeness, reliability, and future maintenance of the Pacific Seabird Monitoring Database, but a draft version of the system is available for review and error-checking by cooperators this year (FY 1998), and wider distribution via the Internet is anticipated within 1-2 years.  Ultimately, this project is intended to foster:  (a) a better coordinated program for monitoring Pacific Seabirds, (b) greater standardization of field methods,  (c) timely availability of resultsówithin 3-4 months after each breeding season as a reasonable goalóand (4) effective use of seabirds as indicators of local and large-scale change in the Pacific marine environment.

An examination of count data for murres (Uria spp.) reveals the strengths and limitations of typical methods for monitoring colonial seabirds that nest in the open.  Murres are broadly distributed and extensively studied in Alaska, Washington, Oregon, and California.  A typical monitoring design in Alaska consists of annual visits to selected colonies, where 5-10 replicate counts of birds on study plots are made over as many days during a well-defined "census period," when daily variation in attendance is lowest.  The statistical power of this approach to detect trends in population size is readily assessed using a computer program (MONITOR) authored by James P. Gibbs of the State University of New York and available on-line through a USGS-BRD website.  We entered the pertinent data on survey designs for murre monitoring into the MONITOR program and determined that power values in the range of 0.8-0.9 are attainable when the goal is detection of a 3-5% annual rate of decline sustained over 10-15 years.  However, power is limited principally by the temporal span of observations, and it declines sharply for studies conducted over fewer than 10 years.  Moreover, we caution against using the MONITOR program incorrectly, which is easy to do.  The appropriate measure of temporal variation to enter is the standard error of estimation from regression analysis (residual variation of annual means about the regression line)ówith an associated sample size of 1 mean count per yearónot the within-season variation of daily counts (sample size 5-10 counts per year in the present example) as instructed in the user's manual that accompanies the program.  To illustrate the effect of incorrectly specifying survey design, we estimated a power value of 0.98 for detecting a 2% annual decline of murres in a 5-year study using inappropriate inputs.  The true power of the survey techniques to detect a 2% annual decline over 5 years is only 0.07.  The optimal allocation of sampling effort within and between years is a related but separate issue that cannot be addressed using the MONITOR program.  Used correctly, MONITOR is accurate and simple to use for assessing past efforts and designing future studies.  Much work remains to be done in applying this tool to seabird monitoring data on a post-hoc basis.

It is essential to maintain at least current levels of effort to monitor Pacific seabirds if this activity is to achieve its goals and fully reward past investments.  This is particularly true given the increasing recognition that much of the environmental variation we wish to detect and understand occurs on decadal, possibly even centenary, temporal scales.  Even as we engage in this activity, however, there is a critical need for both theoretical and empirical investigations into what is "normal," thereby establishing "action thresholds" to apply when examining information on seabird population dynamics.  Faced with a confusing barrage of findings indicating trends of various durations and magnitudes, managers need concrete advice on when to become concerned to the point of expending public resources to address perceived problems.  Given the nature of variation in marine environments and the associated life history traits of marine birds, we believe that population modeling and Monte Carlo methods applied to simulated data sets will likely be  the most productive avenue for research and development in this area.   

1 U.S. Geological Survey, Alaska Biological Science Center, 1011 E. Tudor Road, Anchorage, AK 99503 (e-mail address of first author:  scott_hatch@usgs.gov)  2 U.S. Fish and Wildlife Service, Alaska Maritime National Wildlife Refuge, 2355 Kachemak Drive, Suite 101, Homer, AK 99603-8021  3 Point Reyes Bird Observatory, 4990 Shoreline Highway, Stinson Beach, CA 94970

Monitoring:  Conservation Science or Chicken Soup?  Joseph R. Jehl, Jr.  Hubbs SeaWorld Research Institute  2595 Ingraham Street  San Diego, CA 92109

Monitoring in various forms is integral  to understanding the basic question of population biology: what controls the distribution and abundance of animals.  At small scales, as in determining trends in colonies, it can be extremely useful. For studying species at regional or continental scales its utility is moot. Monitoring depends on the fulfillment of assumptions, whose existence often unappreciated or ignored. And interpreting the results requires detailed knowledge of the target species, which too often is  unavailable.

The central question to this meeting should not be "to monitor or not" but "do we know how to count birds with enough accuracy to mean anything?" Will the results even be interpretable, and can they be made practical? The results of studies of two "easy" species, Wilson's Phalarope and Eared Grebe, suggest not.   For too many species, it will take years to confirm whether population trends are apparent or real. If conservation of avian resources is the proximate goal, that time is not available, particularly for tropical migrants or species affected by fragmentation of habitats,  because of the unceasing growth of human populations and the rate at which governments act. Without immediate and practical programs to detect, understand, and deal with declining populations, monitoring is Chicken Soup--it makes you feel good but has no curative effect. On the bright side, it will provide a superb record of decline and extinction, though not necessarily of causality. That is good enough for historians, but not for biologists.

Monitoring seabird populations in Northeastern North America: a  summary overview for the Atlantic seaboard  David N. Nettleship¹ and Ian C.T. Nisbet²

¹  Canadian Wildlife Service, Environment Canada, 45 Alderney Drive,  Dartmouth, N.S., Canada B2Y 2N6 and Lundy Consulting, 25 Tidewater  Lane, Head of St. Margaret's Bay, Tantallon, N.S., Canada B0J 3J0  ²  I.C.T. Nisbet & Co., 150 Alder Lane, North Falmouth, MA 02556, USA   

The origin of monitoring populations of seabirds worldwide is the belief that their conservation and protection is significant to  biological diversity and the integrity of marine ecosystems.  Generally, the aim of such monitoring programs is to gather detailed  information on patterns of distribution, levels of abundance, habitats  and ecological requirements, and determinants to changes observed in  key population parameters of species present in a geographic marine  region through part or all of the year. The overall objective is to  acquire sufficient knowledge of processes responsible for population  dynamics to be able to identify probable causes of major changes in  population status and take appropriate actions where necessary to  mitigate or remove factors responsible. Most programs are directed at  the population level of individual species or a set of representative  ecological types within a marine system with a particular focus on changes in breeding population size and status.

Vast numbers of seabirds assemble in and utilize the inshore and offshore waters of eastern North America throughout the year. Breeding populations are large. Altogether, about 7.5 million pairs of 32 species breed in the region from Ellesmere Island, Northwest territories south to east Florida. The total for the eastern Canadian arctic and Atlantic Canada is roughly 7.0 million pairs comprising 24 seabird species (ten not in eastern United States), whereas about 500,000 pairs of 23 species nest from the Gulf of Maine to east Florida. These populations are often at risk by human activity in marine regions such as offshore oil drilling and mining, oil spills, commercial fisheries developments, unregulated hunting, use of toxic chemicals, domestic and industrial sewage disposal and the promotion of populations of large gulls and other predatory species. Additional threats include disturbance of breeding colonies from tourism, human predation, coastal habitat alteration and destruction, introduction of  alien predators, climate change, new fishing technologies -- that reduce seabird survival and productivity by either depleting their prey or increasing the risk of by-catch or both -- and offshore oil developments and transport. The increased awareness of the vulnerability of seabirds to this plethora of threats, particularly the discovery of oil on the North Slope of Alaska in 1968 and the likelihood of extensive areas of eastern North America's arctic islands and continental shelf being subjected to oil drilling, led  governmental agencies (Canadian Wildlife Service [CWS] and U.S. Fish & Wildlife Service [USFWS]) to organize and plan comprehensive investigations of seabirds in the northwest Atlantic in the early 1970s.

The push to develop a conservation strategy to protect and maintain seabird populations led to management plans aimed to satisfy three conditions: (1) regulate and control the impact of general environmental stresses on seabirds and their marine habitats in the immediate future; (2) mitigate quickly or halt existing disturbances  causing obvious damage to specific species populations; and (3) provide a dynamic monitoring system capable of measuring important demographic parameters of individual seabird species to determine present status, predict change, and identify causal factors responsible. In Canada, the approach taken to achieve these criteria  centered on the systematic development of a biological monitoring system (BMWs) for eastern Canadian seabirds. Designed in 1971-1972, the aim was not only to examine the distributions and sizes of breeding populations of individual species using standardized census techniques, but also to provide the population biology information essential to understanding the causes of changes detected by monitoring bird numbers. The overall goal was to establish a network of long-term biological studies of a few representative species within each oceanic zone (high arctic, low arctic, boreal) including generalist, specialist, sedentary, migrant, low and high trophic  feeders at sample colonies at the center and edge of the breeding range of those species. Such an approach -- information on distribution and levels of abundance of individual species, breeding performance (measurement of primary demographic parameters of populations), and determinants of changes in key population parameters  -- culminate in an integrated population monitoring plan, or BMS. Because population counts by themselves provide no insight on the cause of any change detected, it is essential to adopt a BMS unified approach to effectively monitor seabird population size and the determinants of change. Similar programs were subsequently initiated  in the eastern United States by both GOs (federal and state agencies) and NGOs (e.g., National Audubon Society).

The results of these long-term monitoring studies have begun to reveal significant changes in seabird populations. In general, highly specialized species such as terns (Sternidae) and alcids (Alcidae) have steadily decreased in numbers, whereas the more generalized and adaptable species such as fulmars and gulls have increased  dramatically. Reasonably good information is available on the numbers and trends of each of the 23 seabird species that breed in the eastern United States, though the most recent censuses were conducted in the period 1976 to 1985. Only four species -- Leach's Storm-petrel, Herring Gull, Gull-billed Tern, and Black Tern -- appear to be  decreasing, whereas 16 are increasing, though many of these are recent small increases following lengthy and marked declines (e.g., terns and alcids). In 1993, the USGS Patuxant Wildlife Research Center initiated a colonial waterbird inventory and monitoring program encompassing all east coast states except Florida. The long-term aim is to conduct complete statewide surveys for colonial waterbirds along the eastern seaboard to determine the status and trends of selected populations of waterbirds at local, regional, and national scales. Presently, researchers from 13 states under federal, state and university contracts have collected species records at about 2600 colonies. This program is scheduled to execute complete censuses at least once every four years (more frequently for certain species) following established protocol and survey procedures. Results from this monitoring exercise should enable the detection of changes in population size and status of most seabird species breeding in the eastern United States.

The current focus of the CWS Seabird Program in eastern Canada is the BMS component of the program: i.e., measurement of reproductive performance and other primary demographic parameters of key seabird species at representative sample colony sites. The populations selected for monitoring based upon the 1972-1975 colony surveys in Arctic and Atlantic Canada either represent a significant proportion of the species total numbers or make up a large fraction of the biomass of the region. In arctic regions north of 60oN, comprehensive baseline studies have been established at six locations since 1975 focusing on Northern Fulmar, Black-legged Kittiwake, Thick-billed  Murre, and Black Guillemot, supplemented by less exhaustive documentation of breeding biology for Glaucous Gull and Ivory Gull. South of 60oN, 14 baseline sites for monitoring were established covering 13 principal boreal water species: Leach's Storm-petrel, Northern Gannet, Double-crested Cormorant, Black-legged Kittiwake,  Herring Gull, Great Black-backed Gull, Common Tern, Arctic Tern, Razorbill, Thick-billed and Common Murres, Black Guillemot and Atlantic Puffin; these monitoring studies are supplemented by others on Great Cormorant, Ring-billed Gull, Caspian Tern, Roseate Tern, and Common Eider. Results from these monitoring studies provide reasonable measures of population status (i.e., in equilibrium or not) for 22 or the 24 species examined. In high and low arctic water zones, most species appear stable or increasing slightly except for Glaucous Gull and Thick-billed Murre. At lower latitudes in low arctic and boreal waters, petrels, gannets, and gulls are stable or increasing in  numbers, with most tern and auk species decreasing, some at an alarming rate such as three Sterna species -- Common, Arctic and Roseate Terns -- and Razorbill and Atlantic Puffin. Others vulnerable to human interference appear vulnerable including Double-crested and Great Cormorants even though both have shown increases during the previous decade. The status of several arctic species remains uncertain owing to the absence of repeat censuses.

Many gaps remain in our knowledge of the status of populations of seabirds in northeastern North America. We still know little about inter-year variation in reproductive performance for most individual species or how it varies within a species at different colonies in the same year. We also need to prepare for the assessment of imminent  threats to seabirds from global warming and other large-scale environmental changes. More generally, we should work to expand a system similar to the biological monitoring system of the CWS seabird program along the Atlantic seaboard to all regions of eastern North America. Seabird researchers and managers in different regions and countries -- United States and Canada -- need to work together to ensure results from seabird monitoring are compatible, that duplication of effort is avoided, and that gaps in information are addressed and filled. We must also develop standardized computerized data management systems to facilitate easy access to seabird colony  data such as the CWS Seabird Colony Registry presently in operation in Arctic and Atlantic Canada. Overall, we must ensure that seabird monitoring is not done in isolation, but is combined with studies of the causes of population change and is applied to management and conservation problems. Currently, however, the larger challenge may well be the attainment of such monitoring goals in the present climate of diminishing resources and governmental interest, particularly in Eastern and Atlantic Canada, in the conservation of seabirds and their marine environments.

Suggested Readings:  Greenwood, J.J.D., S.R. Baillie, H.P.Q. Crick, J.H. Marchant & W.J. Peach. 1993. Integrated population monitoring: detecting the effects of diverse changes. Pp. 267-342 in: Birds as monitors of environmental change (R.W. Furness & J.J.D. Greenwood, eds.). Chapman & Hall, London.

Nettleship, D.N. 1977. Seabird resources of eastern Canada: status, problems and prospects. Pp. 96-108 in: Canada's threatened species and habitats (T. Mosquin & C. Suchal, eds.). Cnadian Nature Federation Special Report no. 6, Ottawa.

Nettleship, D.N. 1991.Seabird management and future research. Colonial Waterbirds 14: 77-84.

Nettleship, D.N. 1993. CWS Seabird population monitoring program: national issues & program priorities 1994-2004. Canadian Wildlife Service "Studies on northern seabirds" Report No. 265: 1-77.

Nettleship, D.N. 1994. CWS Seabird Colony Registry: a computerized data management system for access to seabird colony data. Pp. 27-30 in: Science Review 1992 & '93 (A. Fiander, ed.). Department of Fisheries & Oceans Canada, Halifax.

Nettleship, D.N. 1996. Family Alcidae (The Auks). Pp. 678-722 in:  Handbook of the Birds of the World, Volume 3: Hoatzin to Auks (J. del  Hoyo, A. Elliott & J. Sargatal, eds.). Lynx Edicions, Barcelona.

Nettleship, D.N. 1997. Long-term monitoring of Canada's seabird populations. Pp. 16-23 in: Monitoring bird populations: the Canadian experience (E.H. Dunn, M.D. Cadman & J.B. Falls, eds.). Canadian Wildlife Service Occasional Paper No. 95, Ottawa.

Nettleship, D.N. 1998. Ecosystem disturbance and seabirds in crisis: Eastern and Atlantic Canada. World Wildlife Fund - Canada, Toronto.  (in press)

Nisbet, I.C.T. in prep. Marine birds of the Eastern United States: status and conservation. Manuscript report in: Seabirds of North America: status and conservation requirements (D.N. Nettleship, ed.). Special publication for Stichting Greenpeace Council, Amsterdam. 144 pp.

Monitoring:  How and Why:  J.D. Nichols, USGS, Patuxent Wildlife Research Center, Laurel, MD 20708-4017

Estimation of animal abundance over geographically extensive areas must deal with 2 constraints: (1) typically, animal survey methods (e.g., counts, captures) cannot be physically carried out on the entire area of interest, and inference must be based on samples representing some fraction of the total area of interest; (2) on areas that are part of the sample, our survey methods typically detect some unknown fraction of the animals actually present.  Serious efforts to monitor animal abundance must include reasonable approaches to dealing with these 2 constraints. The first constraint is not peculiar to animal surveys and is characteristic of many large-scale surveys. Traditional approaches to spatial sampling include random, stratified, systematic and cluster sampling. Adaptive cluster sampling approaches have been developed recently for animals exhibiting certain types of spatial distribution patterns.

Historically, the second constraint has been recognized primarily in animal ecology, although this kind of constraint appears to exist in many other application areas as well.  We conceptualize the second constraint by writing the expected value of our count statistic [E(C_i)] for sample time and location i as: E(C_i)=N_i p_i, where N_i is the true abundance for time-location i, andp_i is the associated detection probability (this can be thought of as the probability that an individual in the population is detected and appears in the count statistic).  Numerous methods have been developed to estimate the detection probability associated with specific count statistics.  Such estimation leads directly to estimation of abundance as : N hat sub{i}=C_i / p hat sub{i}, where the hats denote estimators.

Some workers claim that a focus on population "trend" (ratios of population size at different times) requires no interest in detection probability, as trend can be estimated directly as functions (e.g., ratios) of count statistics.  Note, however, that this estimation requires the often-restrictive assumption that detection probability be equal for the times being compared.  Index proponents try to minimize variation in detection probability by: (1) standardization to deal with sources of variation in p_i of which we are aware and over which we can exert control, and (2) measurement of covariates that we recognize as potential influences on detection probability for inclusion in the analysis of count statistics.  However, despite these approaches to dealing with detection probability, I suspect that there are typically many factors influencing detection probabilities that we are not smart enough to have identified. Analyses of count statistics as indices to abundance represent acts of faith that all relevant sources of variation in detection probability have been identified and dealt with via either standardization or the analytic inclusion of covariates.  The preferred approach to trend estimation, in my opinion, involves direct estimation of the detection probability as part of the survey (i.e., obtain the count statistics in a way that permits direct estimation of associated detection probabilities).

I suggest that serious evaluation of animal surveys should involve an assessment of how the 2 listed constraints are addressed by each survey. Very few large-scale animal surveys around the world deal adequately with either constraint.  As models are important, I recommend that those interested in developing or modifying avian monitoring programs look closely at the Breeding Ground Survey of prairie-nesting waterfowl in North America carried out annually by the U.S. Fish and Wildlife Service, the Canadian Wildlife Service and cooperating state and provincial government agencies.  This is the only large-scale survey for birds of which I am aware that was designed to deal with both constraints.

In addition to examining how well designated quantities are estimated by a monitoring program, it is important to ask the purpose of the program, as this will likely be a determinant of the adequacy of resulting estimates.  If we are involved in some sort of management, then I believe that there are 2 explicit roles of monitoring: (1) assessment of current state of the system for use in the current management decision, and (2) investigation of system dynamics and responses to management.  Note that role (1) does not necessarily imply annual or periodic management action, and includes the objective of identifying a threatened or declining population for the purpose of possible action.

Investigations associated with role (2) can be carried out using (a) retrospective analyses, (b) experimental or constrained manipulative studies, or (c) formal adaptive management. I believe that monitoring programs are frequently established with the vague idea that retrospective analyses using estimates of population size, population vital rates, and environmental variables, together with records of past management decisions, will somehow lead to a complete understanding of the system.  The idea is that if the relevant time series are sufficiently long and the estimates sufficiently accurate, then correlation analyses will eventually yield the truth about system dynamics and responses to management. As one of many investigators who has tried to wring such truth out of nearly 50 years of excellent survey data on mallard duck abundance and vital rates, I suggest that retrospective analyses are much more useful for description of past dynamics than for predicting future dynamics or responses to management.  Most investigators who have looked seriously at the mallard data have recommended experimentation and adaptive management as providing the best opportunities for learning from monitoring programs. Implementation of a management action and subsequent comparison of monitoring program estimates with model-based predictions provides a basis for learning about system dynamics and responses to management actions under experimental and adaptive management approaches.

As a model for use of monitoring as part of an ongoing management program, I again point to North American waterfowl. The current program of adaptive management used for North American mallard ducks has explicitly identified the role of monitoring programs in the management process. Four models reflect competing hypotheses about mallard population dynamics and are used to project the consequences of management actions for the purposes of making annual management decisions and assessing model performance (i.e., learning about system dynamics). Estimates of population size are used as one of the primary descriptors of system state and thus form the basis for annual decisions about hunting regulations.  Estimates of population size are also compared with model-based predictions made the previous year, and the differences are used to update model "weights" or probabilities reflecting relative degrees of faith in the different models.  Estimates of environmental variables such as wetland conditions are also used to characterize the state of the system, and estimates of mallard vital rates (survival and reproductive rates) and management-related variables such as harvest rate are used in the modeling process.

BBS and other programs  Bruce Peterjohn and Chandler S. Robbins  USGS Patuxent Wildlife Research Center  Laurel, MD, USA 20708

The 18 programs included in this group can be divided into four basic categories: Distribution, bird-habitat relationships, population trends, and wildlife health.  Breeding Bird Atlases are the best source of distributional information, although the Breeding Bird Survey (BBS), Checklist programs, and Urban Bird Monitoring Program may provide some useful data. Breeding Bird Atlases have been conducted in at least 40 states and provinces, with nearly complete coverage in the eastern third of North America.  Most atlases were conducted during the 1970s and 1980s, and should be repeated in the future to document temporal changes in distributions.  Limitations of  these data include variable timing for completed atlases, variable sampling designs, and that a number of states  have not conducted atlases.  While atlases have been coordinated within states and provinces, there is a need for regional coordination of future atlas efforts so that distributional changes can be better documented at larger geographic scales.

Bird-habitat relationships can be explored through Breeding Bird Census (BBC) data, although data for this program is primarily obtained from woodland habitats in eastern North America.  The Birds in Forested Landscapes is a new program that has more limited taxonomic and habitat coverages, but may provide useful information for bird-habitat relationships in woodlands once data have been collected for several years.  While BBS data have been used to explore bird-habitat relationships in recent years, the utility of point count data collected from  roadside surveys to accurately document these relationships remains to be established.  Our understanding of bird-habitat relationships would be improved through expanding the geographic coverage of the BBC and Birds in Forested Landscapes programs, and to obtain data from habitats other than woodlands throughout the continent.

Population trend data for 450+ species of North American birds are provided by the BBS.  This program was initiated during 1966-1968 and currently consists of approximately 4000 roadside survey routes scattered across the continental U.S., Canada, and Alaska.  The BBS provides population trend estimates at various geographic scales including continental, regional, states/provinces, and physiographic strata, and is the only source of trend information for many species of non-game birds.  Additionally, 10 other programs provide range-wide trend estimates for single species or small groups of species.  Five of these programs are restricted to endemic Hawaiian Island birds, while the Kirtland's Warbler (Dendroica kirtlandii) Count provides data for this endangered species.  The other programs survey Mourning Doves (Zenaida macroura), "night birds", Cerulean Warblers (Dendroica cerulea), and tanagers (Piranga spp.), although only the Mourning Dove Call-Count Survey has existed for more than 10 years and provides trend estimates throughout the U.S. for that species.  Secondary sources of population trend data could be provided from Breeding Bird Atlases, Checklist programs and possibly the BBC.

Of these programs, only the BBS and Mourning Dove Call-Count Survey have been extensively analyzed in the literature.  Both programs survey roadside habitats, and the potential biases associated with the selection of these habitats remains to be determined.  Additionally, a number of observer-related biases complicates any analyses of BBS data, although a detailed discussion of the limitations and potential biases associated with the BBS is beyond the scope of this paper.  The relationship between numbers of birds counted along BBS routes and the size of the actual breeding populations at these points has never been documented, and developing an understanding of this relationship is necessary before the accuracy of the BBS trend estimates can be validated.

The House Finch Disease Survey documents the spread of Mycoplasmal Conjunctivitis among several species of birds visiting feeders, primarily House Finches (Carpodacus mexicanus) and American Goldfinches (Carduelis tristis).  It is the only program monitoring aspects of wildlife health listed in the matrix, although beached bird surveys may also fall under this category.  The House Finch Disease Survey  is not based on systematic samples, but rather on observations of diseased birds reported by cooperators.

Most of these programs provide their data through publications, although the timely appearance of current data is not usually possible in this forum.  The BBS Trend Analysis Home Page (http://www.mbr-pwrc.usgs.gov/bbs/bbs.html) has pioneered the use of the Internet to provide population trend estimates and other results.  Portions of the BBC database are accessible online, while the entire BBS data set should be accessible over the Internet in 1998.  The development of similar home pages would greatly improve the availability of survey data and results from the other programs.

Other issues are also common to most of these monitoring programs.  Formal training procedures are virtually non-existent, and these programs either select observers "based on their familiarity with  species" or provide instructions and other materials for the participants to read.  Hence, the inability of participants to follow specific methodologies or to locate and correctly identify the species of interest can produce substantial variation in the data.  The importance of this problem will vary from program to program, being least critical in surveys of single island endemic species but of greater importance for programs surveying entire breeding communities.  None of these programs has undergone an independent peer review, a process that would help identify existing problems in the programs and suggest solutions that would improve their utility for monitoring various aspects of bird populations.  The analysis of survey data remains a controversial subject, and only data from the BBS and Mourning Dove Call-Count Survey have undergone considerable scrutiny.

These surveys provide a foundation for the development of an integrated monitoring effort for landbirds, obtaining some data on distribution, population trends, and bird-habitat relationships.  Aspects of all of these programs could be improved, however, especially with regards to the training of participants, independent review of program activities, and/or availability and analysis of survey data.  Other important issues need to be addressed, including: 1) How to attract enough qualified participants to conduct these and other surveys; 2)What to do for species that are currently poorly monitored by these programs; and 3) What financial resources are available to accomplish these goals?  Finding solutions to all of these problems will be essential in the development of an overall monitoring strategy for continental bird populations.

A Comparison of point count census methods for monitoring landbirds  C. John Ralph (Redwood Sciences Laboratory, U.S. Forest Service, Arcata, California [cjr2@axe.humboldt.edu])  Richard L. Hutto (Biological Sciences, University of Montana, Missoula, Montana).

    The monitoring of all species of landbirds has severalcomponent parts, the most adopted and active of which isundoubtedly point counts.  Several modifications of point countmethodology include Breeding Bird Surveys, Area Search, and someLine Transects.  All of these have established protocols andusually seek an index of abundance, rather than absolute density. The selection of some sort of "indicator" species to monitor hastaken much effort, much of it perhaps unneeded.  We suggest analternative involving landbird monitoring because of theirmillion point counts are conducted in North America annually, andthe half-life of such data sets is at perhaps 5 years, the restbeing lost.  The urgent need for data repositories has beenrecognized for some years.  The relative lack of progress isprobably due to the costs involved and the amount of concomitantGIS and vegetation data sets.  Several areas are in need of attention, including observer variability, road bias, and the meaning of abundance.  We have excellent indications from severalregions of the continent that the method works well.  We willdescribe a simple program, with important applications, and referto other regional efforts underway that provide good science as well as excellent management direction.

Monitoring activities in the American tropics  E. P. Mallory  Manomet Center for Conservation Sciences  P.O. Box 1770, Manomet, MA 02345-1770  epmallory@compuserve.com

C. S. Robbins  USGS Patuxent Wildlife Research Center  Laurel, MD 20708-4015  chan_robbins@usgs.gov   

Betsy Mallory designed a questionnaire and sent it to researchers known to be working in the American tropics.  She has summarized the results of 32 responses by computer.

 In addition to such standard information as locality, years, seasons, investigators, and details of methodology, the questionnaire requested categorization by habitats (following Stotz et al.), information on conservation threats to the study sites, extent of government oversight over research, research permits required, involvement and training for local people, and whether in-country institutions are using the results to solve local problems.  Information on funding sources and prognosis for continued monitoring at the site was also requested, as was an estimate of people-hours of field time and number of species detected.

Mexico, Costa Rica, and Belize are the best represented. Scattered reports were received from other countries in Central and South America, but only two from the West Indies.

 Most sites reported they had personnel on site or did some patrolling.

 About half the sites contain some tropical lowland evergreen forest, and half have secondary forest.

 Only two projects have more than 20 years of data, five projects have data for 5-7 years, seven projects have data for 3-4 years.  Many are optimistic (overly?) of ongoing status.

 21 of 32 studies used point counts, 7 used strip counts, 9 used area search, 5 used spot mapping, 22 used mistnets, and 9 do nest searches (only 7 regularly and only 7 for all species).  Only 6 monitor nest success.

 We are still looking for more projects to be included, and will have English and Spanish versions of the questionnaire available at the meeting.

Are counts censuses?  Ruminations on the role of statisticians in a review of monitoring methods  John R. Sauer, USGS Patuxent Wildlife Research Center, 11510 American Holly Drive, Laurel, MD.  (Email: john_r_sauer@usgs.gov)

An enormous amount of information is available about North American bird populations.  Checklists collected at National Wildlife Refuges, atlases, visibility-adjusted waterfowl surveys, nest records, and banding studies all provide some information about bird distribution, abundance, and population change.  Moreover, most all of this survey information is georeferenced at some level, allowing its use in Geographic Information Systems (GIS).  Finally, almost all the data are in the public domain, allowing access to any interested user.  This availability has led to use of most of these surveys in attempts to estimate temporal or spatial change in some attribute of bird populations.

However, there are lingering doubts about the extent and quality of the information.  There is concern that estimates from most surveys are biased, by either inappropriate selection of areas to be sampled or by use of data collection methods that provide incomplete counts within samples.  Even for well-designed surveys, new uses are constantly devised.  Information needs for the new uses are often very specific, requiring unbiased and precise estimates, and it is often difficult to judge the value of existing surveys for the new uses.  Changing information needs for management also require estimates at different geographic scales than those provided by existing surveys.

Challenging the surveys with new uses often helps us to better understand the value and limitations of the data, but unless careful attention is paid to estimation the new uses can also lead to production of biased estimates and an undermining of the credibility of the surveys.  The North American Breeding Bird Survey (BBS) provides an excellent example of both the opportunities and limitations of use of survey data.  The BBS is now a primary source of information for estimation of spatial and temporal aspects of bird population change at many geographic scales.  However, it is clear that there are great differences of opinion about what constitutes appropriate analyses of the data.

In part, these differences reflect interdisciplinary differences in approaches to data analysis and interpretation.  Design and analysis of bird surveys is a collaborative effort, requiring the efforts of both ornithologists, mathematical statisticians, and other quantitative scientists such as applied statisticians, programmers, and GIS specialists.  Although ornithologists provide the species expertise and ecological context for hypothesis testing, statisticians provide the critical understanding of sampling and estimation that underlie the credibility of any biological sampling.   In any review of monitoring programs by ornithologists, it is critical that statisticians be equal partners.  Here, I discuss how greater statistical input in survey discussions would assist in resolving controversies about appropriate survey methods and analysis, with particular emphasis on the use of indices of population size.

Many controversies in analysis of count data relate to the notion of incomplete counts.  There is a fundamental disagreement about the use of counts as indexes to both population size and population change.  Everyone recognizes that counts are underestimates of population size at a site, in that some birds are missed during counting.  Statisticians generally believe that this visibility rate must be estimated to provide credible estimates of any population attribute; however, many users of count data assume that counts are censuses, or that visibility rates are constant, and use counts as an index to population size.  This is not a trivial point, as the index assumption is implicit in all components of design and analysis of surveys, and it makes most analyses of survey data problematic.   In this talk, I briefly discuss a few situations where assumptions about visibility rates play a critical role in defining our views of the validity of count data, including:   I.  Effort adjustments in Christmas Bird Count data and use of observer change as covariates in BBS data as post-hoc attempts to accommodate visibility differences.   II. We often compare survey methods by implementing and comparing alternative indexes for a common area.   These comparisons are meaningless without a knowledge of bias of the alternative estimates.   III. Comparisons of survey analysis results from different surveys are often meaningless, as we cannot generally determine which estimates are less biased.   IV.  Implementation of standards and observer training are often regarded as activities that will eliminate visibility differences, when in practice visibility differences can always invalidate comparisons.   Any reasonable analysis of count survey data requires explicit acknowledgment of the role of visibility rates as a possible source of bias.

Monitoring the distribution and abundance of the birds of North America  J. Michael Scott, Patricia Heglund, Rita Dixon, University of Idaho; and Jonathan Bart, U.S. Geological Survey, Boise Idaho.

Knowledge of trends in distribution and abundance of the bird species found in North America is of interest to policy makers and conservationists, as well as professional biologists.  How common is it?  Where can I find it?  Is it decreasing, increasing, or stable in its numbers?  These are frequently asked questions, and questions we don't always have answers for.  They are questions that require extensive monitoring if we are to answer them for every species.  In this presentation, we will present the results of our efforts to identify all current attempts to track the abundance and distribution of the birds of North America.  We restricted our efforts to those that were comprehensive taxonomically or geographically during at least one season.  We identified 60 programs that met these criteria.  We determined which species lacked coverage and how many species were covered by more than one program.  In the future, we hope to provide information on how reliable trend information is for each species. Our goal is to provide a database of national monitoring programs for researchers interested in the quality, quantity, and coverage of established programs.  This database will be available on the World Wide Web in the near future.  We found the effectiveness of monitoring efforts varied among different behavioral, ecological, taxonomic, conservation, and legal categories in which we grouped species.  Few training programs and even fewer evaluation programs exist.  Thus, adjustments and additions to current monitoring efforts are needed if we are going to answer basic questions regarding the status and distribution of North America's avifauna.

Why Monitor Birds?  Jared Verner  Forestry Sciences Lab  2081 E. Sierra Ave.  Fresno, CA  93710

With six other panelists addressing the same question, I doubt whether I have anything substantive to add to the "why" of monitoring.  We monitor primarily to track the status and trends of populations.  This information aids in the identification of circumstances (e.g., serious decline of a species, or marked increase in numbers of a species that would be better kept at lower numbers) that may warrant more intensive study or specific management measures.  When linked with good habitat data, monitoring data can also be used to improve our assessments of species-habitat relations.

My main concern as a participant in this workshop is to encourage more widespread understanding of (1) the limitations of monitoring methods and (2) the importance of following rigorous sampling protocols designed to reduce the impacts of biases.  For example, practitioners need to understand that general efforts to monitor trends at local or regional scales will typically produce reliable trend data only for relatively abundant species.  Answers simply won't be there for most of the uncommon to rare species--those likely to be of most interest.  Failure to account for observer variability can obscure real population trends and real population differences in two-sample comparisons of relative abundance between sites or before and after habitat change at a single site.

Why monitor birds?  A conservation agency's perspective.  James D. Wilson, Ornithologist, Missouri Department of Conservation

Bird monitoring projects have provided an abundance of information on the long-term trends of bird species and communities.  Negative trends in bird populations can frequently be correlated with changes in land use or other forms of environmental degradation.  As agencies responsible for managing and protecting wildlife resources, conservation departments can develop and implement management strategies to address problems that have been revealed by monitoring projects. The Missouri Department of Conservation has carried on an array of monitoring projects, most involving annual surveys.  Many of the initial projects focused on species whereas later projects tend to address groups, guilds or communities.  Through experience we have learned that the most useful monitoring projects are those that have been developed with an application in mind.  Additionally, monitoring should use standard methodology so that results can be compared with similar projects in different places and times. And, most importantly, results must be readily available to managers, to those conducting environmental reviews, and to researchers and state Heritage Programs.  The Missouri Department of Conservation has used monitoring results to develop management plans, select lands for acquisition and flag species or groups that need special attention.  Results of monitoring projects, such as the Breeding Bird Survey, have been used to identify species for listing or those needing recovery plans.    Several major habitat management programs in Missouri are a consequence of bird monitoring projects.  These include timber harvest procedures that reduce forest fragmentation, reforestation of bottomlands, restoration of prairie landscapes and provision and protection of marsh habitat.  These programs would likely never have been considered had monitoring projects not documented the loss of wetland habitat and declines among forest, riparian and grassland birds.  As our Department has expanded its efforts in the area of nongame bird management, more monitoring is needed to evaluate the success of this management.  Realizing the potential application of bird monitoring results, projects should be designed and conducted so that they will yield needed and useful information.