SPECIES

Puerto Rican Bullfinch Melopyrrha portoricensis Scientific name definitions

John Faaborg and Amber Wiewel
Version: 2.0 — Published February 18, 2022

Plumages, Molts, and Structure

Plumages

The following description is based on Ridgway (1).

Immature

Upperparts deep olive-brown. Underparts paler olive-brown or olive; undertail coverts orange-rufous.

Adult

Male. Crown (except forecrown and supercilium), chin, throat, center of the breast, and the undertail coverts orange-rufous. Rest of plumage, including the sides of the breast, uniform rich black.

Female. Similar to adult male, but with the black slightly less intense.

Molts

The Puerto Rican Bullfinch is one of a very few Puerto Rican bird species that has a distinct juvenile plumage when a young bird fledges. During a study of molt from October 2008 to September 2009 (except August 2009), J. Toms found a few individuals in first basic plumage in every month of the year (personal communication). Molt was observed in some individuals in most months of the year, although flight feather molt appeared to be most common in the late summer and fall. During January mist-netting, many juvenile birds are undergoing extensive body molt to adult plumage in some years, while in other years few juveniles are observed, which could be because molt had already occurred or because few young were produced the previous summer. It also is possible that body molt is not synchronized among individuals due to differences in individual body condition, age or breeding status. The above data are from Guánica Forest, which has an extremely seasonal climate; timing of molt could differ on other parts of the island with less extreme environmental conditions.

Bare Parts

Bill

Bill of adults of both sexes are black. Immature bill is dusky. Nestlings have pink-gray bills.

Iris and Facial Skin

The iris is black.

Tarsi and Toes

Tarsi and toes of adults of both sexes are black. Immature legs and feet are dusky. Nestlings have dark gray tarsi and toes. Bill, tarsi, and toes darken to black over the nestling period (AW, unpublished data).

Measurements

Linear Measurements

Overall length: 16.5–19 cm (2).

Male (n = 7; 1):

  • wing length: mean 89.9 mm (range 86.6-93.0 mm).
  • tail length: mean 73.2 mm (range 69.6-77.7 mm).
  • bill length (exposed culmen): mean 16.5 mm (range 15.5-17.5 mm).
  • bill depth (at base): mean 14.0 (range 13.2-15.0 mm).
  • tarsus length: mean 23.9 mm (range 23.4-24.4 mm).

Female (n = 5; 1):

  • wing length: mean 83.1 mm (range 80.0-88.4 mm).
  • tail length: mean 70.9 mm (range 67.1-76.2 mm).
  • bill length (exposed culmen): mean 15.0 mm (range 14.0-17.3 mm).
  • bill depth (at base): mean 13.5 (range 11.9-15.0 mm).
  • tarsus length: mean 22.9 mm (range 21.8-24.6 mm).

Mass

Male mean 34.8 G SD 2.56 (range 26.7-44.8 g, n = 389); female mean 29.5 g SD 2.71 (range 23.4–45.5 g, n = 332) (3).

Recommended Citation

Faaborg, J. and A. Wiewel (2022). Puerto Rican Bullfinch (Melopyrrha portoricensis), version 2.0. In Birds of the World (T. S. Schulenberg and J. Gerbracht, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.purbul1.02