Neotropical Birds
Version  1.0
This is a historic version of this account.   Current version

Castelnau's Antshrike Thamnophilus cryptoleucus

Thomas S. Schulenberg and Gary H. Rosenberg
Version: 1.0 — Published April 27, 2012


Distinguishing Characteristics

Thamnophilus antshrikes are medium to large sized antbirds with stout, hooked, "shrike"-like bills and relatively long tails. Both sexes of Castelnau's Antshrike are black, with a semiconcealed white interscapular patch. The male also has narrow white tips and edges to the wing coverts.

Similar Species

Few other sympatric species of antshrike are as black as Castelnau's Antshrike, and no other similar species occupies the same habitat as Castelnau's. The male White-shouldered Antshrike of western Amazonia (Thamnophilus aethiops kapouni) is very dark gray; it has a few white spots on the wing coverts, but these are much less prominent than in male Castelnau's. White-shouldered Antshrike also is restricted to the interior of terra firme forest, and does not occur on river islands or in the successional habitats occupied by Castelnau's Antshrike.

Detailed Description

Sexes differ. The following description is based on Zimmer and Isler (2003):

Adult male: Black overall, with white interscapular patch (usually more or less concealed). Tips of scapulars white. Tips and edges of wing coverts white. Rectrices black, but sometimes the outer rectrices have very small white tips. Flanks and posterior underparts dark gray. Underwing coverts white.

Adult female: Similar to adult male, but scapulars and wing coverts entirely black.

Subadult: Similar to adult female, but browner.


Bare Parts

Iris: brown

Bill: black

Tarsi and toes: blue-gray

Bare parts color information from specimens in the Louisiana State University Museum of Natural Science.


Total length: 16-17 cm (Zimmer and Isler 2003), 17-18 cm (Ridgely and Greenfield 2001b), 18 cm (Hilty and Brown 1986)

Linear measurements:

These data are from Cory and Hellmayr (1924), and, contra Cory and Hellmayr (1924), are for females (Todd 1927):

wing length: 73.5 mm, 78 mm

tail length: 60 mm, 60.5 mm

tarsus length: 26 mm

bill length: 22 mm, 23 mm

Mass: 30-35 g (Zimmer and Isler 2003; sample size?)

Recommended Citation

Schulenberg, T. S. and G. H. Rosenberg (2012). Castelnau's Antshrike (Thamnophilus cryptoleucus), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.casant1.01
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