Gray-headed Tanager Eucometis penicillata

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

Breeding

Breeding occurs in Central America from March-September; in eastern Brazil (Pará) breeding occurred in February, September, November, and December. Males have been observed bringing food to a female mate during precopulatory activities and during incubation. Copulation usually follows feeding. Nest building begins in March (Willis 1985). The nests are small, thin, loose cups, usually built about 0.5 to 3 m off the ground in a palm tree, orange tree, coffee shrub and hedges, generally in areas with thick undergrowth. Wetmore et al. (1984) described one nest that measured 10 cm in outside diameter and was 5 cm high, with the inside cavity 7.5 x 5 cm in diameter and 4 cm deep. A pair usually builds the nest together. They take turns finding materials for the nest (rather than coming and going together) and come back to deposit the materials, such as rootlets and fungal hyphae, to shape the nest. Occasionally, they will pass the materials to the partner already sitting inside of the nest. Of 24 Grey-headed Tanagers nests observed in Costa Rica, only 9 were successful. Nest failure is mostly due to predation by snakes, squirrels and other nest predators. Clutch size: two eggs are usually laid per clutch on consecutive days, but nests with only one or up to three eggs have been observed (Skutch 1954, 1989, Isler and Isler 1999). Eggs: Brown and black in color, heavily marked, and may completely mask the pale blue-gray color underneath. Mean eggs dimensions are 24.2 x 17.33 mm (Wetmore et al. 1984). Incubation: 14-16 days. Incubation may begin anywhere from 0-5 days after the nest has been completed, and only the females incubate. Parental Care: Parental care lasts 11-12 days in which both parents feed the nestlings about four times per hour during this period and also perform nighttime brooding to incubate the young over night. Nestlings hatch with closed eyes, pink skin and sparse, gray downy feathers. A 12 day old nestling has well developed plumage and has ability for weak flight (Skutch 1954, 1989, Hilty and Brown 1986, Isler and Isler 1999). Young stay with their parents much of the time until they develop an adult plumage at about seven months. After this point, parents and young may rejoin occasionally, and by the next breeding season pairs are on their own (Willis 1985).

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