Gray-headed Tanager Eucometis penicillata

  • Order: Passeriformes
  • Family: Thraupidae
  • Polytypic: 7 subspecies
  • Authors: Carly S. Baker and Kevin J. Burns
Sections

Appearance

Distinguishing Characteristics

The Gray-headed Tanager is a brightly colored, moderately sized tanager. It has olive to yellow upperparts, bright yellow underparts, and a conspicuous gray head and crest (Hilty and Brown 1986).

Similar Species

Gray-headed Tanagers may be mistaken for female White-shouldered Tanagers (Tachyphonus luctuosus), female Black-throated Shrike-Tanagers (Lanio aurantius) or Gray-hooded Bush-Tanagers (Cnemoscopus rubrirostris), all of which share a similar plumage pattern. The Gray-headed Tanager can be distinguished from these species by its gray crest. In addition, the Gray-headed Tanager typically forages closer to the ground than these species; it is smaller than the Black-throated Shrike-Tanager and larger than the White-shouldered Tanager and Gray-hooded Bush-Tanager (Ridgely and Tudor 1989, Howell and Webb 1995, Restall et al. 2007). There also is little or no overlap in elevational distribution with the bush-tanager, which occurs above 1900 m in the Andes.

Detailed Description

Adults: Overall, both males and females are olive yellow with a gray head. The wings are yellowish olive with darker margins, and underwing coverts are yellowish. Its namesake gray head has a crest of white feathers tipped with gray. The crest is usually laid flat against the head but can be raised when the bird is agitated (Ridgely and Tudor 1989). The chest is a conspicuous bright yellow and the throat is pale white. The tail is pale brown with yellowish olive margins. Willis (1985) noted that the yellow and green pigments of this species blends well with dappled foliage; however, the yellow underparts are more conspicuous closer to the ground. The sexes of the Gray-headed Tanager are similar, but males of at least one subspecies (E. p. albicollis) have a longer crest (Ridgely and Tudor 1989). An analysis of coloration using an avian visual model confirms the lack of sexual dichromatism for most plumage regions; however, the belly and flanks differ slightly between males and females (A. J. Shultz and K. J. Burns, unpubl. data).

Immatures and subadults have a reduced crest and usually lack a gray head (Schulenberg et al. 2007). Instead, the head is greenish olive and the throat olive-yellow (Isler and Isler 1999). Nestlings less than 12 days old have pink skin with sparse gray feathers (Skutch 1989). At about seven months, young are finishing wing molt and look similar to adults (Willis 1985).

Molts

Willis (1985) reported the timing of molt from young to adult plumage for the following locations: Central America (late May-late October), northern Colombia and Venezuela (April-early September), southern Brazil (mid April-late June).  For adult birds, molt takes about four months and timing varies geographically (Willis 1985).  From Mexico to northern Colombia and Venezuela, adult birds begin molt in June to August and end molt from October to December (Willis 1985). From Mato Grosso to São Paulo, molt begins in November or December and lasts to March, while birds in Amazonia and Guyana molt from February to July (Willis 1985).

Bare Parts

Bill: hazel and white underneath with a large rounded notch on upper mandible, subconical, compressed, and much shorter than rest of head (Clark 1913).

Iris: bright reddish brown (Wetmore et al. 1984).

Tarsi and toes: pale brown; claws dull slate (Ridgway 1902, Wetmore et al. 1984).

Measurements

Total length: 16-17 cm (Isler and Isler 1999)

Mass, both sexes: mean 27 g (range 22.5-35.0 g; n=52; Isler and Isler 1999)

Table 1- Length measurements of various parts of the body, measurements in mm, from Ridgway (1902).
Sex Body Wing Tail Culmen Depth of Bill Tarsus Middle Toe
Male 156 89.9 75.9 12.7 6.9 21.8 15
Female 153.8 83.8 72.4 14 6.9 22 15.7

Table 2- Length measurements of various parts of the body, measurements in mm, specimens from Costa Rica and Panama, from Wetmore et al. (1984).

Sex Wing Tail Culmen (from base) Tarsus
Male 89.5 76.8 17.1 21.3
Female 86.3 74.2 16.9 21.3


Recommended Citation

Baker, C. S. and K. J. Burns (2010). Gray-headed Tanager (Eucometis penicillata), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.grhtan1.01