Castelnau's Antshrike
Thamnophilus cryptoleucus
Large black antshrike with a white back patch. Males have white wingbars, absent in females. An inhabitant of seasonally flooded forests, second growth, and river islands with dense understory composed of Cecropia and Heliconia vegetation. Forages in the understory and rarely accompanies mixed-species flocks. The song is an accelerating series of low descending notes.
Identification
Castelnau's antshrike is 16 to 18 cm (6.3 to 7.1 in) long and weighs 30 to 35 g (1.1 to 1.2 oz). Members of genus Thamnophilus are largish members of the antbird family; all have stout bills with a hook like those of true shrikes. This species exhibits slight sexual dimorphism. Adult males are mostly black. They have a mostly hidden white patch between their scapulars, white tips on the scapulars, white tips and edges on their wing coverts, sometimes very small white tips on their flight feathers, and white underwing coverts. Their flanks and belly are dark gray. Adult females are similar to males but their scapulars and wing coverts are entirely black. Subadults are similar to adult females but browner. Both sexes have a brown iris, a black bill, and blue-gray legs and feet.
Taxonomy
Castelnau's antshrike was originally described as Myrmelastes cryptoleucus. By the principle of priority, Myrmelastes is junior to Myrmeciza. In 1924 it was transferred to that genus and then in 1927 to its current Thamnophilus. Later some authors treated Castelnau's antshrike as a subspecies of the blackish-grey antshrike (T. nigrocinereus), but that approach was not widely accepted. They are now considered sister species. Castelnau's antshrike is monotypic.
- Scientific name
- Thamnophilus cryptoleucus
- Authority
- (Ménégaux & Hellmayr, 1906)
- Order
- Passeriformes
- Family
- Thamnophilidae
- Genus
- Thamnophilus
Range and habitat
Castelnau's antshrike is found along the upper Amazon River and its major upstream tributaries. It occurs along the Rio Napo in Ecuador and Peru to where it enters the Amazon. In Ecuador it also occurs along the Río Pastaza and presumably further downstream on that river in Peru. In Peru it also occurs along the rios Marañón and Ucayali. In Colombia it occurs in the extreme south along the Amazon, and in Brazil along the Amazon almost to the Rio Negro. Castelnau's antshrike is found almost exclusively on river islands but also occurs on the "mainland" near the rivers. In all areas it occurs mostly in dense understorey but commonly into the mid-storey as well. In elevation it occurs only as high as about 300 m (1,000 ft).
- Migration
- Resident species
Behavior
Migration pattern: Resident species.
Conservation
Population trend: declining.
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
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Black-throated Magpie-Jay
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Yellow-breasted Racquet-tail
Prioniturus flavicans
A large green parrot with a thin pair of tail rackets, confined to North Sulawesi and satellite islands. Entirely green, except for distinct yellow wash on breast and collar. Males show a small red crown patch. Juveniles lack rackets. Found in pairs and groups in canopy of forests and edges in lowlands and foothills. Prominent yellow breast and large size of this species distinguish it from Golden-mantled Racquet-tail. If rackets are not seen, note the silvery-gray bill, unlike Blue-naped Parrot. Noisy, giving varied vocalizations. Song is a high-pitched “kut-ut-ut-kler-kler.” Also gives screeches, squeaking, piping, and ear-splitting “kraa” notes.
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