C. n. perneglectaMayr, 1944 – eastern and central Lesser Sunda Islands[6]
Description
The drab swiftlet is 9–10 cm (3.5–3.9 in) in length with a square tail.[7] It has a satin grayish-blue back with slightly glossy crown and tail. The throat and the upper breast is a mid-gray with a lighter margin to the feathers. The lower breast, flanks and belly are white but the rump is dark. There are dull white spots on the inner webs of the tail feathers. Most birds have a tuft of feathers on the hallux, the rear facing toe. Subspecies perneglecta is darker and has more gloss on the feathers.[4]
^ abRheindt, Frank E.; Christidis, Les; Norman, Janette A.; Eaton, James A.; Sadanandan, Keren R.; Schodde, Richard (2017). "Speciation in Indo-Pacific swiftlets (Aves: Apodidae): integrating molecular and phenotypic data for a new provisional taxonomy of the Collocalia esculenta complex". Zootaxa. 4250 (5): 401–433. doi:10.11646/zootaxa.4250.5.1.
^Chantler, P.; Boesman, P. (2017). del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D.A.; de Juana, E. (eds.). "Glossy Swiftlet (Collocalia esculenta)". Handbook of the Birds of the World Alive. Lynx Edicions. Retrieved 23 August 2017.