Research Training ProgramSmithsonian
Institution
|
|
| Moritz Weinbeer University of Würzburg D-97074 Würzburg, Germany Charles Handley, Ph.D. "The RTP unifies with unlimited scientific value the smallest details of biology with the greatest overview of natural history" |
 |
|
|
Bats of Isla Escudo de Veraguas, Panamá: a study of Systematics, Evolution, and Biogeography
ABSTRACT
Because they are completely isolated, islands offer outstanding opportunities for direct investigations of evolutionary processes such as immigration, extinction, and speciation that are quite difficult to study in non-isolated habitats. It was not until the time of C. Darwin and A.R. Wallace that processes occurring on islands have been put into the context of general evolution. Since those days many investigations have focused on the biogeography of islands, favoring plants, birds, and also quite a number of mammals, particularly rodents, as subjects of study. However, very little effort has been directed to the bats living on islands and archipelagoes. Bats, as well as birds, are to some extent different from many other animals, as they have the ability of real flight. This makes them better colonizers, especially of farther islands, but also more prone to extirpation processes. On the other hand, on islands that were formed in a progressive manner, these animals are more likely to stay in contact over long periods of time with populations from which they were derived, depending on the degree of isolation of the island. This work focused on the nectar-feeding bat Glossophaga soricina handleyi, Phyllostomidae, occurring on all islands of the Bocas del Toro archipelago. These islands differ in age, size, and type of vegetation. It has been assumed by several studies that small animals tend to be larger on islands, whereas large animals tend to be smaller than their mainland counterparts. Skin and skull measurements of Glossophaga soricina handleyi show a slight tendency of being larger on the farthest island, Isla Escudo de Veraguas. Additionally 20 qualitative cranial characters were chosen. A cluster analysis of these characters not only mirrors the exact scale of the age of the islands, but also clearly separates the individuals of Escudo from the individuals of the other islands.
This research was kindly supported by a grant from the Smithsonian Women's Committee.
