Birdfinding.info ⇒ A localized endemic form of Broad-winged Hawk. Readily found at Río Abajo State Forest and adjacent parts of Puerto Rico’s northwestern haystack hills. Also occurs in and around El Yunque National Forest, but it has become scarce there in recent years.
“Puerto Rican Broad-winged Hawk”
Buteo platypterus brunnescens
Endemic to Puerto Rico, where it is rare and local in humid montane and foothill forests. Currently known from three disjunct areas: Río Abajo State Forest in the northwest; the Sierra de Cayey (Carite State Forest) in the southeast; and the Sierra de Luquillo (El Yunque National Forest) in the northeast. Historically occurred throughout the island.
In 1992, the total population was estimated at 124 individuals (U.S.F.W.S. 1997), with about 40% at Río Abajo, 40% in the Sierra de Cayey, and 20% at El Yunque.
Identification
Generally resembles other forms of Broad-winged Hawk, but darker than most, with a consistent pattern.
The adult’s underparts are a mix of reddish brown and cream color—not as white as base color of “Northern.” The upper breast is mostly dark with a few pale spots. The lower breast and belly are evenly barred.
“Puerto Rican Broad-winged Hawk,” P. b. brunnescens. El Yunque National Forest
“Puerto Rican Broad-winged Hawk,” B. p. brunnescens. (Arecibo Observatory, Puerto Rico; April 1, 2012.) © Nancy Crosby
“Puerto Rican Broad-winged Hawk.” (Río Abajo State Forest, Puerto Rico; April 18, 2014.) © Jay McGowan
“Puerto Rican Broad-winged Hawk,” B. p. brunnescens, adult with large chick. U.S. Fish and Wildlife Service
“Puerto Rican Broad-winged Hawk,” B. p. brunnescens. (Río Abajo State Forest, Puerto Rico; December 29, 2017.) © Jenna Curtis
“Puerto Rican Broad-winged Hawk,” B. p. brunnescens. (Río Abajo State Forest, Puerto Rico; October 20, 2018.) © Peter Kaestner
Immature “Puerto Ricans” are similar to those of other forms.
“Puerto Rican Broad-winged Hawk,” B. p. brunnescens, immature. (Río Abajo State Forest, Puerto Rico; December 16, 2016.) © Steve Semanchuk
Cf. Red-tailed Hawk. The only other Buteo on Puerto Rico is the much larger Red-tailed Hawk, which usually has pale underparts, although dark morphs and immatures could cause confusion.
Adult “Puerto Rican Broad-winged Hawk” is most reliably distinguished by its tail, which has broad dark and pale bands, whereas the Red-tailed’s tail can either be unmarked or have a single, narrow dark subterminal band.
Immature “Puerto Rican Broad-winged Hawk’s” tail has a single, narrow dark subterminal band, which may allow confusion with Red-tailed, particularly as immatures of both have boldly streaked underparts. Broad-winged is smaller and proportionately thicker-bodied and broader-winged—not as lanky as Red-tailed.
Notes
Monotypic form, one of three potentially distinct forms of Broad-winged Hawk.
The U.S. federal government lists it as Endangered.
References
eBird. 2019. eBird: An online database of bird distribution and abundance. Cornell Lab of Ornithology, Ithaca, N.Y. http://www.ebird.org. (Accessed April 14, 2019.)
Ferguson-Lees, J., and D.A. Christie. 2001. Raptors of the World. Houghton-Mifflin, Boston.
Raffaele, H., J. Wiley, O. Garrido, A. Keith, and J. Raffaele. 1998. A Guide to the Birds of the West Indies. Princeton University Press, Princeton, N.J.
U.S. Fish and Wildlife Service. 1997. Puerto Rican Broad-winged Hawk and Puerto Rican Sharp-shinned Hawk (Buteo platypterus brunnescens and Accipiter striatus venator) Recovery Plan. https://ecos.fws.gov/docs/recovery_plan/970908.pdf.
Vilella, F.J. and D.W. Hengstenberg. 2006. Broad-winged Hawk (Buteo platypterus brunnescens) movements and habitat use in a moist limestone forest of Puerto Rico. Ornitología Neotropical 17: 563-579.
White, C.M., P. Boesman, and J.S. Marks. 2018. Broad-winged Hawk (Buteo platypterus). In Handbook of the Birds of the World Alive (J. del Hoyo, A. Elliott, J. Sargatal, D.A. Christie, and E. de Juana, eds.). Lynx Edicions, Barcelona. https://www.hbw.com/node/53124. (Accessed February 4, 2018.)