About Pheucticus ludovicianus (Linnaeus, 1766)
Scientific name: Pheucticus ludovicianus (Linnaeus, 1766). Description. Adult rose-breasted grosbeaks are 18–22 cm (7.1–8.7 in) long, have a wingspan of 29–33 cm (11–13 in), and weigh 35–65 g (1.2–2.3 oz). Grosbeaks measured during migration in the West Indies had an average weight of 43 g (1.5 oz), while individuals banded in Pennsylvania average about 45 g (1.6 oz). Very little sexual dimorphism in size occurs; females are marginally smaller in standard measurements, but in some seasons, banded females in Pennsylvania were marginally heavier than males. At all ages and in both sexes, the beak is dusky horn-colored, and the feet and eyes are dark. Adult males in breeding plumage have black heads, wings, back, and tail, with a bright rose-red patch on the breast. The wings have two white patches and rose-red linings, and the underside and rump are white. Nonbreeding adult males have mostly white underparts, supercilium, and cheeks. Upperside feathers have brown fringes, and most wing feathers have white fringes, creating a scaly appearance. The bases of the primary remiges are also white. When seen clearly, adult male rose-breasted grosbeaks are unmistakable, even during the winter. Adult females have dark grey-brown upperparts, which are darker on the wings and tail. They have a white supercilium, a buff stripe along the top of the head, and black-streaked white underparts that have a buff tinge everywhere except the center of the belly. The wing linings are yellowish, and the upperwing has two white patches, just like breeding males. Immature rose-breasted grosbeaks are similar to adult females, but have pink wing-linings, less prominent streaks, and usually a pinkish-buff hue on the throat and breast. One-year-old males in their first breeding season are scaly on the upperparts like fully adult males in winter plumage, and still retain the browner wings of immatures. Where their ranges overlap in the central United States and south-central Canada, female rose-breasted grosbeaks can easily be confused with female black-headed grosbeaks (Pheucticus melanocephalus). Compared to female black-headed grosbeaks, female rose-breasted grosbeaks have slightly darker brown markings on the underside, paler rather yellowish streaking on both the head and wings, and a paler, pinkish (rather than bi-colored) bill. Female purple finches (Haemorhous purpureus) are another potential confusion species, but purple finches are noticeably smaller with a less robust bill and a notched tail. The rose-breasted grosbeak's song is a subdued mellow warbling, similar to a more refined, sweeter version of the American robin's (Turdus migratorius) song. Males begin singing early, occasionally even when they are still in their winter quarters. The call is a sharp pink or pick, somewhat similar to a woodpecker call. Distribution and habitat. The rose-breasted grosbeak's breeding habitat is open deciduous woods across most of Canada and the northeastern United States. Northern populations migrate south through the United States east of the Rocky Mountains, to winter from central-southern Mexico through Central America and the Caribbean to Peru and Venezuela. The southern limit of its wintering range is not well understood; for example, it was only recorded in the SerranÃa de las Quinchas, Colombia, in the 1990s. In winter, the species prefers more open woodland, or similar habitat with loose tree growth such as forest edges, parks, gardens, and plantations. It ranges from sea level into the hills, for example up to 1,500 m (5,000 ft) above mean sea level in Costa Rica. Since 1966, the rose-breasted grosbeak has had a greater than 1.5% yearly population decline across the eastern part of its summer range, while the western parts of its summer range have seen a matching yearly population increase of over 1.5%.
