Tuesday, February 24, 2015

Treeswifts––Pure Elegance!

Among many highlights of our recent trip to Cambodia and Borneo were treeswifts––the ultimate in avian elegance!

Related to swifts and hummingbirds, treeswifts comprise one small family of only four species. For a long time they confounded ornithologists, who placed them with swallows. Even their scientific name reflects the confusion: Hemiprocne, or "half-swallow". 

On this recent trek to Asia, we were delighted to see three of the four treeswifts: Crested, Whiskered, and Gray-rumped. 

Crested Treeswifts grace the skies of Tmatboey, Cambodia
(Photos by Narca)

Most treeswifts live in more open, edge habitats, where they swoop through the air like especially acrobatic swallows to catch their insect prey, but the lovely Whiskered Treeswift is a species of primary evergreen forest, where it works a different kind of edge. It soars in the spaces around the canopies of emergent trees, acrobatically scouring the upper edge of the tall forests for its food. Only rarely does it venture into second-growth forest.

Male Whiskered Treeswifts sport deep rufous cheeks...

while the female's cheeks are blackish. 
This pair was in the Danum Valley, Borneo.

Pairs of Whiskered Treeswifts stay in their year-round territories, where they nest at the tips of slender branches (probably as a defense against predation by snakes). Their small nests are built of bits of bark, leaves and feathers, cemented by their saliva. They lay a single egg, which completely fills the tiny cup.

I never tire of watching the graceful flight of treeswifts!