Nombre en español: Mirla Collareja
Nombre en inglés: White-necked Thrush
Nombre científico: Turdus albicollis
Familia: Turdidae
El zorzal cuelliblanco (Turdus albicollis) también conocida como mirla collareja, tordo de collar blanco, zorzal collar blanco, o zorzal cuello blanco, es una especie de ave paseriforme de la familia Turdidae que vive en diversas regiones de Sudamérica, tales como Colombia, Venezuela, Brasil, la zona norteña de Argentina, en Trinidad y Tobago y en Perú.
La Mirla collareja es usualmente solitaria o en parejas y es muy perseguida como ave de jaula por su canto. Su nombre Turdus significa mirla en latín. El epíteto albicollis significa de cuello blanco, viene de las raíces latinas albus= blanco y collus= cuello.
Morfología
Es un ave que mide 26 cm aproximadamente. La parte superior de la cabeza y las articulaciones son negras, con las plumas de la frente marginadas de café blanco. El resto de las partes superiores es gris obscuro con tintes oliváceo. La garganta es blanquecina y tiene estrías negras. El pecho, el vientre y las plumas subcaudales son de color amarillo claro. En los juveniles el pecho es rayado. Las alas y la cola son negras. El pico y las patas son de color amarillo.
Especies similares
Similar a la Mirla ollera (Turdus ignobilis) especialmente la subespecie T.i debilis que no tiene garganta tan bien marcada (estrías negras menos nítidas y parche blanco más pequeño) y muestra menos contraste entre las partes superiores e inferiores.
Regionales
En Colombia se reconocen dos subespecies T. a phaeopygoides y T.a phaeopygus.
Distribución
Se distribuye en la Sierra Nevada de Santa Marta y Serranía del Perijá hasta los 1500m, se distribuye además en la vertiente oriental en extremo norte, Guamalito, en Norte de Santander y en los Andes hasta los 1000m desde Norte de Santander y Vichada hasta Vaupés y Nariño.
Habitat
Es relativamente común (fácilmente desapercibida excepto por su canto) en selva húmeda de tierra firme y várzea, a veces en bordes.
Alimentación
La Mirla Collareja se alimenta principalmente cerca del suelo de invertebrados. Así mismo, toma un poco de fruta y bayas. Se observa regularmente siguiendo ejércitos de hormigas.
Reproducción
Ponen de 2 a 3 huevos azul verdoso pálido marcados de café. El nido es una taza hecha de ramas colocadas (a una altura de 1-9 m) en un árbol o arbusto.
Comportamiento
Escondidizo y difícil de ver, permanecen en sotobosque, a veces hasta nivel medio. Es un ave regular en suelo de la selva y puede seguir marchas de hormigas. Usualmente solitario o en parejas y muy perseguido como ave de jaula por su canto.
Taxonomía
Forman dos grupos, el » grupo assimilis «de Mesoamérica y el «grupo albicollis»de América del Sur, comúnmente se tratan como dos especies distintas. Además, la subespecie daguae recientemente ha sido considerada como una especie distinta. Tres especies (albicollis, paraguayensis , crotopezus ) se han propuesto como representantes de una especie más en función de las diferencias de menor importancia. En todos los casos, sin embargo, la evidencia para dividirlas no ha sido coherente, y en algunos casos implica evaluaciones subjetivas vocales en gran medida.
White-necked thrush
The white-necked thrush (Turdus albicollis) is a songbird found in forest and woodland in South America. The taxonomy is potentially confusing, and it sometimes includes the members of the T. assimilis group as subspecies, in which case the «combined species» is referred to as the white-throated thrush (a name limited to T. assimilis when the two are split). On the contrary, it may be split into two species, the rufous-flanked thrush (T. albicollis) and the grey-flanked thrush (T. phaeopygos).
Description
This thrush is 20 1⁄2–26 cm (8.1–10.2 in) long and weighs 40–77 g (1.4–2.7 oz). The upperparts are dark brown, turning duskier or greyer towards the ocular region. The throat is white with dense dark streaks, except on the lowermost part, resulting in the appearance of a white crescent below the dark-streaked white throat. This has given rise to both its English and scientific name. The crissum (the undertail coverts surrounding the cloaca) and central belly are whitish, and the chest is grey often tinged brown. The members of the nominate group have conspicuous rufous flanks, and the bill is yellow with a dusky culmen. The flanks are paler and more tawny in the subspecies crotopezus, which also has the entire upper mandible dusky. The members of the phaeopygos group lack contrasting rufous or tawny flanks, and have bills that are almost entirely dusky. All subspecies have pinkish-brown legs and a reddish or yellow eye-ring. Sexes are similar, but juveniles are duller, with dull orange spotting above, and brownish spotting below.
The song is a relatively musical, often rather monotonous two-e-o, two-e. The calls is a distinctive wuk, while the alarm is a rough jjig-wig-wig.
Distribution and habitat
The nominate group (including subspecies paraguayensis and crotopezus) occurs in eastern Brazil, far northern Uruguay, eastern Paraguay and far north-eastern Argentina. The phaeopygos group (including subspecies phaopygoides, spodiolaemus and contemptus) is mainly found in the Amazon Basin, but with populations extending along the eastern slope of the Andes as far south as north-eastern Argentina, and as far north as western Venezuela, with extensions along the Coastal Range, the region centered around Serranía del Perijá and Sierra Nevada de Santa Marta, and the islands of Trinidad and Tobago.
Both groups are mainly associated with humid forest and woodland. In the case of the nominate group, mainly the Atlantic Forest, and in the case of the phaeopygos group, mainly the Amazon Rainforest or humid forests and woodlands near mountains. It rarely ventures far from cover.
Behavior
The white-necked thrush mainly feeds on or near the ground on invertebrates. It also takes some fruit and berries. It regularly follows army ant swarms, but does not attend mixed species flocks. Throughout most of its range, especially in the Amazon, it is a shy species, heard far more than seen, but in Trinidad and parts of south-eastern Brazil it may be less retiring.White-necked thrush at nest
The nest is a lined cup of twigs placed low (at a height of 1–9 m [3.3–29.5 ft]) in a tree or bush. Two to three reddish-blotched green-blue eggs are laid and incubated by the female alone for 12–13 days. Social mongamous, but extra-pair mate are common.
Taxonomy
T. albicollis sometimes includes the members of the T. assimilis group as subspecies, in which case the «combined species» is referred to as the white-throated thrush (a name limited to T. assimilis when the two are split). Published evidence supporting either treatment is weak, but most recent authorities have followed the split.
On the contrary, it has been suggested that the nominate group and the phaeopygos group of T. albicollis should be considered separate species, but the voices of the two are similar, and the subspecies crotopezus from the nominate group approach members of the phaeopygos group in both plumage and colour of bill. If the two groups are split, the common name rufous-flanked thrush has been suggested for T. albicollis, with T. phaeopygos retaining the common name white-necked thrush or being renamed grey-flanked thrush.
Generally considered to represent a species apart from the White-throated Thrush (Turdus assimilis), which is confined to Middle America and South America west of the Andes, the White-necked Thrush is very widely distributed across much of South America east of the Andes, from northern Venezuela to northern Argentina and Uruguay. Compared to the White-throated Thrush, this species usually has rather bright-colored (apricot) flanks and a partially or wholly yellow (rather than mainly dark) bill, but shares the white foreneck and dark-streaked throat, which are the two most obvious plumage features of the latter. Like its presumed sister-species, the White-necked Thrush is generally a bird of the forest interior and, although it can be highly responsive to playback, the species is perhaps most likely to be observed visiting a fruiting tree. However, the species can sometimes descend to the ground, for example when joining other birds at an ant swarm.
Fuentes: Wikipedia/eBird/xeno-canto/WikiAves/Neotropical Birds
