Pygmy Swiftlet

The pygmy swiftlet (Collocalia troglodytes) is a species of swift in the family Apodidae. It is endemic to the Philippines.

Its natural habitat is subtropical or tropical moist lowland forests. At under 9 cm (3.5 in), it is the world's smallest swift. It weighs only 5 grams.

Swiftlets that nest in complete darkness in caves can use echolocation, the ability to position an object by reflected sound, used by other animals such as dolphins and bats.

References

• Price, J. J., Johnson, K. P., & Clayton, D. H. (2004). The Evolution of echolocation in Swiftlets. Journal of Avian Biology 35(2), 135–143. doi: 10.1111/j.0908-8857.2004.03182.x
• Thomassen, H. A., Den Tex, R., De Bakker, M., & Povel, G. (2005). Phylogenetic relationship among Swifts and Swiflets . Molecular Phylogenetics and Evolution, 37(1), 264–277. doi: 10.1016/j.ympev.2005.05.010