Cherry-throated Tanager

识别特征

The upper side is ashy grey, with a darker back and a lighter top of the head. A wide black mask extends from the forehead across the eyes, nearly meeting again at the nape; a small white line runs above it, and thus the forehead appears white when seen from the front. The wings and the square-tipped tail are black, with blue iridescence on the primary and secondary wing-coverts, and a striped patch formed by the light grey outer web of the tertiary remiges, with the grey scapulars sometimes dropping over the wings to form a grey shoulder patch. The uppertail coverts are likewise black, quite long, and have white tips that may have a signal function as they are sometimes prominently presented by the birds. The belly is white, and the throat has a patch of cherry red that varies in extent, in some birds reaching onto the breast. The feet and toenails are dull pink, and the iris is dark yellow.<p>Males and females probably look much alike, though it may be that the latter have a smaller red throat patch on average. Juveniles apparently have the throat patch dull brown.<p>In the field, the cherry-throated tanager is only likely to be confused with the rather common Paroaria cardinal-tanagers which have a similar color pattern when seen from a distance. At close range however, the distribution of black in N. rourei's plumage is distinctive.<p>The type specimen is 14 cm (5,5 inch) long, with wings of 8,3 cm (3,25 in) and a tail of about 6 cm (2,4 in) length. Its bill is 1 cm (0,4 in) long along the ridge, 1,5 cm (0,6 in) long along the gape, and the tarsometatarsus (lower "leg") measures about 1,9 cm (0,75 in). A specimen banded in 1998 was smaller, at 12,5 cm (c. 5 in); its bill was 5,5 mm (0,22 in) high and 5 mm (0,2 in) wide and it weighed 22 g (0,78 oz).<p>The cherry-throated tanager has a clear, far-carrying call, at 5-6 kHz. This note is given singly, or in a row of 2-3 in rapid succession. In the latter case, it is often followed by 2 slightly higher-pitched (8 kHz) notes; an entire 5-note sequence takes a mere second for the bird to utter. There is a kind of song, which consists of the same notes as the call does, interspersed with a more rapid chittering.

分类信息

学名

Nemosia rourei

命名信息

Cabanis, 1870

目

Passeriformes

科

Thraupidae

属

Nemosia

分布与栖息地

迁徙

Resident species

行为

The verified records of the species were all at altitudes of 850–1,250 m ASL in Atlantic Dense Montane Rainforest ecotone; whether the altitude range reflects restriction of habitat or genuine preference is not known. It was never recorded from open forest and usually avoids secondary forest and plantations (coffee, eucalyptus, Pinus elliottii and Pinus patula), though if the canopy cover is dense enough it may utilize plantations and secondary rainforest as corridors to move between patches of prime habitat.<p>The cherry-throated tanager moves through its habitat singly, in pairs (especially during breeding season) or in small flocks led by a dominant bird. If undisturbed, it utilizes regular "tracks" to visit feeding sites over the course of the day; these tracks vary according to season. It is apparently a resident bird; there is no indication even for altitudinal migrations. The species, like many tanagers, joins mixed-species feeding flocks. Those in which N. rourei was observed to participate were usually led by Sirystes and contained chestnut-crowned becards and rufous-headed tanagers as "core" species. The food of adult birds at least seems to consist entirely or nearly entirely of small invertebrates such as caterpillars, butterflies, ants, and other arthropods; Eucalyptus flowers are visited though it is not clear whether to feed on nectar or on nectar-feeding insects. Food is taken by gleaning and clambering through branches to look under leaves as typical for tanagers; the birds do not hang down from branches like titmice.<p>A golden-chevroned tanager was once observed to dominate over a cherry-throated tanager individual, and a black-necked aracari was seen to attack the species for purposes unknown. There exists an observation of an apparent intraspecific threat pose, in which the head and neck are extended and held horizontally, and the wings are half-spread.<p>Longevity is unknown, but not presumed to differ from roughly one decade common among mid-sized passerines. The single ringed bird is known to have lived for at least 6 years.<p>No good data exists, but apparent courtship activity was observed in October, and birds were observed to collect nest-building material in November. What seems to be young birds close to independence but still accompanied by their parents were observed in late February. Considering the usual time from egg-laying to fledging is 2–3 weeks in tropical tanagers, this would seem to fit rather well with the main nesting season being in December/January, just as in most tanager species with similar ecology.

保护状况

种群趋势

declining