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Thamnophilus zarumae

Chapman's Antshrike

  • Order: Passeriformes
  • Family: Thamnophilidae
  • Polytypic 2 Subspecies

Authors: Schulenberg, Thomas S.

Identification

Summary

The Chapman's Antshrike is similar to a slightly smaller, paler version of the widespread Barred Antshrike (Thamnophilus doliatus); but there is no geographic overlap between these two species.

Similar Species

The male Chapman's Antshrike is the only barred antshrike found west of the Andes in southwestern Ecuador or in northwestern Peru; it is unlikely to be confused with any other species. Fasciated Wren Campylorhynchus fasciatus is superficially similar (gray, with a barred back), but differs in many ways: the wren is more social, has a very different voice, a longer tail, a more slender bill, etc. The female Chapman's Antshrike differs from the female Collared Antshrike Thamnophilus bernardi by the plain, unmarked wings.

Vocalizations

The song lacks the characteristic terminal "bark" of the song of the Barred Antshrike Thamnophilus doliatus. The song consists of three elements: it begins with an accelerating series of 12-14 nasal notes, followed by three higher pitched, broad amplitude notes and then ending in a short rattle or trill (Zimmer and Isler 2003, Lane in Schulenberg et al. 2007; see also Parker et al. 1995). Calls include an "abrupt 'chup' " (Zimmer and Isler 2003) and "a high, descending, mewing whistle: 'peew' " (Lane in Schulenberg et al. 2007; this probably is the same as the "slightly longer downslurred note" described by Zimmer and Isler [2003]).

Nonvocal Sounds

None reported.

Detailed Description (appearance)

Male: Crown and crest black, forecrown streaked with white. Superciliary, and sides of the head and neck, streaked black and white. Nuchal collar unmarked, medium gray. Center and lower back, scapulars, rump and wings black, barred with white. Tail black, each rectrix with five to six white bars. Throat white, streaked with black. Breast and sides white, lightly barred with black. Center of belly white. Flanks and undertail coverts cinnamon buff. Immature (first basic?) males are similar to adults, but are barred cinnamon buff (not white) and black on the back, and the remiges are dusky (not black), barred with cinnamon buff. The pale bars on the rectrices also may be buff or cinnamon buff, especially along the outer web and at the feather tip.

Female: Crown rufous. Superciliary, auricular, and sides of the neck whitish buff, streaked black. Nuchal collar olive brown. Center of back, rump, wings and tail more or less uniform cinnamon rufous. Throat pale buff, finely streaked with black. Breast, belly and sides buff, with faint gray barring or speckling on the breast.

Bare Parts

Iris usually pale: yellow-white, pale yellow-brown, gray, pale brown, brown or reddish-brown (specimen data, Louisiana State University Museum of Zoology); grayish yellow or brown (Zimmer and Isler 2003).

Maxilla black; mandible blue-gray.

Tarsus blue-gray.

Measurements

Total length 15.5 cm (Ridgely and Greenfield 2001), 14-15 cm (Zimmer and Isler 2003), 15 cm (Schulenberg et al. 2007).

Mass: x = 21.9 g, range 19.2-23.2 g, SD ± 1.3 g (n = 8); specimen data, Louisiana State University Museum of Zoology, Museum of Vertebrate Zoology. 21-23 g (Zimmer and Isler 2003).

Molts

Not studied.

Geographic Variation

There are two subspecies of Chapman's Antshrike, which do not differ greatly in appearance:

zarumae Chapman 1921; type locality Zaruma, El Oro, Ecuador.

The range of nominate zarumae extends from southwestern Ecuador (El Oro and Loja) into extreme northern Peru (Tumbes; Wiedenfeld et al. 1985).

palamblae Zimmer 1933; type locality Palambla, Piura, Peru.

This subspecies occurs in Piura and Lambayeque, Peru. It is very similar to zarumae, but differs (in the male) by having fainter white markings on the upperparts, a buffier belly, and more strongly ochraceous flanks and vent; and (in the female) by darker upperparts generally, with a darker rufous crown, and by having deeper ochraceous flanks. The plumage differences between the two subspecies may be clinal (Zimmer and Isler 2003).

Systematics

Chapman's Antshrike originally was described as a separate species (Chapman 1921), but was considered conspecific with Barred Antshrike Thamnophilus doliatus soon thereafter (Zummer 1933).  The differences in plumage, song, and to some extent in behavior led to the recognition again of zarumae as a full species (Parker et al. 1995).

Brumfield and Edwards (2007) investigated the phylogenetics of Thamnophilus antshrikes, using DNA from three mitochondrial genes as well as two introns from a nuclear gene. Surprisingly, Thamnophilus zarumae is not the sister to Thamnophilus doliatus, but instead was sister to a clade composed of Bar-crested Antshrike Thamnophilus multistriatus, Lined Antshrike Thamnophilus tenuepunctatus, and Chestnut-backed Antshrike Thamnophilus palliatus; these four species in turn are the sister to the clade that includes Thamnophilus doliatus.

Recommended Citation

Schulenberg, Thomas S.. 2010. Chapman's Antshrike (Thamnophilus zarumae), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=368226