Broad-winged Hawk (Buteo platypterus)

Broad-winged Hawk

Description

The broad-winged hawk (Buteo platypterus) is a medium-sized hawk of the genus Buteo. During the summer, some subspecies are distributed over eastern North America, as far west as British Columbia and Texas; they then migrate south to winter in the Neotropics from Mexico south to southern Brazil. Other subspecies are all-year residents on Caribbean islands. As in most raptors, females are slightly larger than males. Broad-winged hawks' wings are relatively short and broad with a tapered, somewhat pointed appearance. The two types of coloration are a dark morph with fewer white areas and a light morph that is more pale overall. Although the broad-winged hawk's numbers are relatively stable, populations are declining in some parts of its breeding range because of forest fragmentation.

Distribution And Habitat

The Broad-winged Hawk is a rare and endemic non- migratory subspecies in Puerto Rico (Raffaele and others 1998), mostly restricted to El Yunque National Forest, and in Carite and Río Abajo Commonwealth Forests, where it is most abundant (Oberle 2018). However, it has also been reported for the Toro Negro, Maricao, and Guajataca Commonwealth Forests (J.A. Salguero-Faría, personal observation 2009). It is an extremely rare visitor in Vieques (Gemmill 2015). Currently, this species is restricted to dense broadleaf forests in the mountains (Oberle 2018, Raffaele and others 1998). The atlas fieldwork yielded a total of 15 records within 13 hexagons or 3 percent of the 479 total hexagons (see map). Of the 13 hexagons where this species was found, breeding met the atlas definition of probable in 8 percent (1) and possible in 77 percent (10), while the species was observed in 15 percent (2) of the hexagons but without evidence of breeding (see map). Broad-winged Hawk distribution. The map shows the highest breeding code by hexagon and overlaying the ecological life zones in Puerto Rico. Note: percentages may not total 100 due to rounding. 171Broad-winged Hawk/Guaraguao de Bosque

Breeding Habits

Previously published reports indicate that the Broad-winged Hawk builds a large bulky stick nest in a tree or on a cliff from January to July (Raffaele and others 1998), but most of the nesting activity occurs in February and March (Oberle 2018). Atlas results indicate that breeding activity for this species peaks in April, suggesting this species may also breed outside of the period described in the literature. Results show that the Broad-winged Hawk mostly breeds within the subtropical wet and subtropical moist forest life zones (73 and 27 percent of the hexagons, respectively) (see table and map).

Conservation

Overall, the Broad-winged Hawk (B. platypterus) is listed as a species of least concern by the IUCN (BirdLife International 2016). Locally, however, the subspecies (B. p. brunnescens) is listed as critically endangered by local laws (PRDNER 2015) and as endangered by Federal laws (USFWS 1973). In Puerto Rico, the Broad-winged Hawk has a protected habitat in land of 34 percent or 106 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (311 km2).