The rose-breasted grosbeak (Pheucticus ludovicianus), colloquially called "cut-throat" due to its coloration, is a large, seed-eating grosbeak in the cardinal family (Cardinalidae). It is primarily a foliage gleaner. Males have black heads, wings, backs, and tails, and a bright rose colored patch on their white breast. Males and females exhibit marked sexual dimorphism.
Breeding habitat consists of cool-temperate open deciduous woods throughout much of eastern North America, with migration to tropical America in winter. Rose-breasted grosbeaks have an average maximum lifespan of 7.3 years in the wild, and up to 24 years in captivity. Death in the wild is generally due to collision with objects (buildings, cars, etc.) and predation, to eggs, nestlings and adults.
Taxonomy In 1760 the French zoologist Mathurin Jacques Brisson included a description of the rose-breasted grosbeak in his Ornithologie based on a specimen collected in Louisiana. He used the French name Le gros-bec de la Louisiane and the Latin Coccothraustes Ludoviciana. The two stars (**) at the start of the section indicates that Brisson based his description on the examination of a specimen. Although Brisson coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature. When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition, he added 240 species that had been previously described by Brisson. One of these was the rose-breasted grosbeak. Linnaeus included a brief description, coined the binomial name Loxia ludoviciana and cited Brisson's work. This species is now placed in the genus Pheucticus that was introduced by the German naturalist Ludwig Reichenbach in 1850. The species is monotypic.
The genus name Pheucticus is from Ancient Greek φευκτικός - pheuktikós, "shy", from - pheúgo, "to flee", and the specific ludovicianus is from Neo-Latin and refers to Louisiana.
Description
Adult birds are long, span across the wings and weigh .Rose-breasted Grosbeak, All about BirdsCRC Handbook of Avian Body Masses by John B. Dunning Jr. (Editor). CRC Press (1992), . Grosbeaks measured during migration in the West Indies averaged , while those banded in Pennsylvania average about .Faaborg, J. R. and J. W. Terborgh. 1980. Patterns of migration in the West Indies. in Migrant birds in the Neotropics: ecological, behavior, distribution and conservation. (Keast, A. and E. S. Morton, Eds.) Smithson. Inst. Press, Washington, D.C.Clench, M. H. and R. C. Leberman. 1978. Weights of 151 species of Pennsylvania birds analyzed by month, age, and sex. Bull. Carnegie Mus. Nat. Hist. 5. Very little sexual dimorphism in size is seen; females were found to be marginally smaller in standard measurements, but in some seasons were marginally heavier than males when banded in Pennsylvania.Godfrey, W. E. 1986. The birds of Canada. Rev. ed. Natl. Mus. Nat. Sci. Ottawa, ON.Pyle, P. 1997. Identification guide to North American birds. Pt. 1: Columbidae to Ploceidae. Slate Creek Press, Bolinas, CA. At all ages and in both sexes, the beak is dusky horn-colored, and the feet and eyes are dark.
The adult male in breeding plumage has a black head, wings, back, and tail, and a bright rose-red patch on its breast; the wings have two white patches and rose-red linings. Its underside and rump are white. Males in nonbreeding plumage have largely white underparts, supercilium, and cheeks. The upperside feathers have brown fringes, and most wing feathers white ones, giving a scaly appearance. The bases of the primary remiges are also white. The coloration renders the adult male rose-breasted grosbeak (even while wintering) unmistakable if seen well.
The adult female has dark grey-brown upperparts – darker on wings and tail – a white supercilium, a buff stripe along the top of the head, and black-streaked white underparts, which except in the center of the belly have a buff tinge. The wing linings are yellowish, and on the upperwing are two white patches like in the summer male. Immatures are similar, but with pink wing-linings and less prominent streaks and usually a pinkish-buff hue on the throat and breast. At one year of age—in their first breeding season—males are scaly above like fully adult males in winter plumage, and still retain the immature's browner wings. Unlike males, females can easily be confused with the black-headed grosbeak (Pheucticus melanocephalus) where their ranges overlap in the central United States and south-central Canada. The rose-breasted grosbeak female has slightly darker brown markings on the underside, paler rather yellowish streaking on both the head and wings and paler, pinkish (rather than bi-colored) bill when compared to the female black-headed grosbeak.Morlan, J. 1991. Identification of female Rose-breasted and Black-headed grosbeaks. Birding 23:220-223. A potential confusion species also is the female purple finch (Haemorhous purpureus), but that species is noticeably smaller with a less robust bill and a notched tail.
The song is a subdued mellow warbling, resembling a more refined, sweeter version of the American robin's (Turdus migratorius). Males start singing early, occasionally even when still in winter quarters. The call is a sharp pink or pick, somewhat reminiscent of 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. In particular, the northern birds 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 known; it was, for example, only recorded in the Serranía de las Quinchas (Colombia) in the 1990s. In winter, they prefer more open woodland, or similar habitat with a loose growth of trees, such as forest edges, parks, gardens, and plantations, ranging from sea level into the hills, e.g. up to above mean sea level in Costa Rica.Olson et al. (1981), Stiles & Skutch (1989), Hilty (2003) Since 1966 the rose-breasted grosbeak has experienced a greater than 1.5% yearly decline in population throughout the eastern part of its summer range, but a coincident >1.5% yearly increase in western parts of its summer range.
Migration The first birds leave the breeding grounds as early as August, while the last ones do not return until mid-late May. In general, however, they migrate south in late September or in October, and return in late April or early May. It appears as if they remain on their breeding grounds longer today than they did in the early 20th century, when migrants were more commonly seen in May and August than in April or September. The rose-breasted grosbeak occurs as a very rare vagrant in western Europe.Henninger (1906), OOS (2004) During breeding it is fairly territorial; in winter, it typically travels in small groups, and sometimes in larger flocks of a dozen or more.
Behaviour and ecology
Breeding Rose-breasted grosbeaks were the only one of 70 migratory songbird species in the eastern United States shown in males to have produced sperm while still far south of their breeding location.Quay, W. B. 1985. Cloacal sperm in spring migrants: occurrence and interpretation. Condor 87:273–280. Male grosbeaks tend to arrive a few days to a week before the females and pair formation apparently occurs on the breeding grounds.Dunham, D. W. 1966. Territorial and sexual behavior in the Rose-breasted Grosbeak, Pheucticus ludovicianus. Z. Tierpsychol. 23:438–451. Nest building begins from as early as early May in Tennessee to as late as early June further north in Saskatchewan.Nicholson, C. P. 1997. Rose-breasted Grosbeak. Pages 325–327 in Atlas of the breeding birds of Tennessee. (Nicholson, C. P., Ed.) Univ. of Tennessee Press, Knoxville.Macoun, J., and J. M. Macoun. 1909. Catalogue of Canadian birds. Dep. Mines, Geol. Surv. Branch, Ottawa, ON. Egg laying may occur anytime from mid-May to mid-July, as has been recorded in Quebec.Pelletier, R., and D. Dauphin. 1996. Rose-breasted Grosbeak. Pages 954–957 in The breeding birds of Quebec: atlas of the breeding birds of southern Québec. (Gauthier, J., and Y. Aubry, Eds.) Assoc. québecoise des groupes d'ornithologues, Prov. of Quebec Soc. for the protection of birds, Can. Wildl. Serv., Environ. Canada, Québec Region, Montréal. Usually only a single brood is laid by these grosbeaks each summer but second broods are suspected in Canada and confirmed in semi-captivity.Watts, G. E. 1935. Life history of the Rose-breasted Grosbeak (Hedymeles ludoviciana). Master's Thesis. Cornell Univ. Ithaca, NY.Peck, G. K., and R. D. James. 1998. Breeding birds of Ontario: nidiology and distribution: passerines (1st rev.-pt. C: tanagers to Old World sparrows). Ont. Birds 16:111–127. Both the male and the female apparently participate in selecting and building the nest, which is on a tree branch, over vines or any elevated woody vegetation.Roberts, T. S. 1932. The birds of Minnesota. Univ. of Minnesota Press, Minneapolis. Nests have been recorded at off the ground, averaging high, almost always in the vicinity of openings in woodlands.Scott, D. M. 1998. Laying hours and other nesting data of Rose-breasted Grosbeaks. Ont. Birds 16:88–93. Nests are typical of many passerines in both construct, material and size, made from leaves, twigs, rootlets or hair.Baicich, P. J., and C. J. O. Harrison. 1997. A guide to the nests, eggs, and nestlings of North American birds. 2nd ed. Academic Press, San Diego, CA. Clutches are from 1 to 5 eggs, normally being 3–4, being pale blue to green with purplish to brownish red spotting.Best, L. B., and D. F. Stauffer. 1980. Factors affecting nesting success in riparian bird communities. Condor 82:149–157. Males do a third of the incubation roughly, the female doing the remaining amount, and incubation can last from 11 to 14 days. Nestlings are at hatching and after 3–6 days of age, they gain at least each day. The young grosbeaks typically fledge at 9–13 days of age and are independent of their parents after approximately 3 weeks.
Longevity and mortality