Research Training Program

Joaquin Aldabe
Universidad de la República
Montevideo, Uruguay

Carla Dove, Ph.D.
Storrs Olson, Ph.D.
Supervising Scientists
Vertebrate Zoology - Birds

"I feel really happy and satisfied with
this beautiful experience. It made me
see the usefulness of science to society
and encouraged me to dedicate my life
to biological research."

Morphological adaptations for terrestrial habits of the Scimita-Billed Woddcreeper (Drymornis bridgesii).

Woodcreepers are Neotropical birds renowned for their tree climbing habits. It is on the trunks and branches of trees where almost all species forage, reproduce, and sleep, using their strong tail feathers as a body support in the same way as woodpeckers (Picidae). However, there is one species, the Scimitar billed Woodcreeper (Drymornis bridgesii), that has attracted the attention of ornithologists because it regularly descends from trees to feed on the ground, where it is even capable of running - with a little difficulty. This species occurs in open habitats such as the savannas of south central South America. As form and function are extremely correlated, this research anticipated confirmation that the Scimitar billed Woodcreeper would be very different from its' tree climbing relatives. Characters of the bones, claws, and tail feathers were studied. It turned out that the proportion of the metatarsal length (distal leg bone) in relation to whole leg length is larger in the Scimitar billed Woodcreeper than in the rest of the species studied, an adaptation to increase movement capability on the ground. Differences were also found in the tip width of the central feathers of the tail. Drymornis has a markedly thinner tip of the tail feathers because it doesn't use the feathers of the tail to support its weight as extensively as the rest of the woodcreepers. However, no differences in claw curvature were found, and Drymornis has a typical woodcreeper claw that aids in climbing. The results show that the Scimitar billed Woodcreeper has clear anatomical modifications that support its characteristic ground foraging habits. However, it is not completely changed to terrestrial life, as claw curvature shows. The Scimitar billed Woodcreeper has retained some of its original tree-climbing adapatations to facilitate hiding and nesting in trees.

This research was supported by a grant from the Smithsonian Latino Initiatives Fund.

Letter of gratitude