Great Dusky Swift Cypseloides senex

  • Order: Caprimulgiformes
  • Family: Apodidae
  • Monotypic
  • Authors: Connor Rosenblatt


Detailed Description

The following description is based on Chantler (2000):

Adult: Sexes similar. Feathers of the top of the head chocolate brown, with blackish shaft streaks and distinct pale gray fringes. The pattern on the throat is similar. Consequently the head has an overall pale or "frosted" appearance, especially for fore parts (forecrown, lores, and chin). The back is blackish brown, clearly darker than the head and nape; the rump and uppertail coverts are slightly paler than the back (but darker than the head), and very lightly pale fringed. The rectrices are blackish brown. The greater wing coverts are blackish brown, paler tipped; the other coverts are uniformly blackish brown. The remiges are blackish brown; the inner primaries and the secondaries are paler tipped, especially on the inner webs. The underwing is only slightly paler than the upper surface, and are only slightly paler than the greater coverts. The median and lesser coverts are darker and browner.

Juvenile: Similar to adult, but with very narrow pale fringes to the remiges. On the underwing, median coverts are paler than the greater coverts; the outerwebs of the underwing primary coverts are basally white.



Bare Parts

Bill and toes black.


Total length: 18 cm (Sick 1993, Chantler 2000).

Lineear measurements (from Navarro et al. 1992; n = 2, sex?)

wing length (chord): mean 160.5 ± 2.5 mm

tail length: mean 46.0 ± 1.5 mm

tarsus length: mean 20.47 ± 0.05 mm


mean 99.8 g (range 86.1-110 g, n = 33, sexes combined, Argentina; Dunning 2007)

mean 67.8 g (range 56-80 g, n = 8, sexes combined, Brazil; Dunning 2007)

Recommended Citation

Rosenblatt, C. (2014). Great Dusky Swift (Cypseloides senex), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.