Formicario di Urrao

Identificazione

The bird most closely resembles the brown-banded antpitta, which is endemic to the Cordillera Central of Colombia, but it has a slate-grey breast and lacks the brown flanks and breast band of the other species. Measurements of the living bird from which Barrera and Bartels' holotype material was derived, as well as of the two collected specimens, show weights ranging from 53.5 to 57.4 grams (1.89 to 2.02 oz), flat wing chords of 95–99 millimetres (3.7–3.9 in), tail lengths of 57–63 millimetres (2.2–2.5 in), and tarsus lengths of 44.5–49.9 millimetres (1.75–1.96 in). The sexes are similar in appearance, as with most other antpittas.<p>A captured fledgling was covered with dark grey down with brown edges above and was buff below. Its feet were dark pink; its bill was black above and orange below, with conspicuous red-orange edges. A captured juvenile looked scaled, with patches of chestnut-edged black down intermixed with grey feathers on much of its body, and a buff belly. Its bill resembled that of the fledgling.<p>The song comprises three notes of increasing length and frequency. The birds sing more early in the year. The call is a single note, higher-pitched than the song, which rises, falls, and rises again. The birds often give it in response to loud noises and playbacks of its vocalisations. They call more later in the year. Both song and call resemble those of the brown-banded antpitta, but Fenwick's antpitta's notes are shorter and lower-pitched, and those of its song are separated by wider intervals.

Tassonomia

Within its genus, the bird is a typical member of the plain-coloured group due to its relatively small wings, fairly uniform upperparts and underparts without strong markings, relatively high tail / wing ratio, a convolute inner edge of the tarsus, and 12 rectrices. It is evidently most closely related to the brown-banded antpitta, G. milleri, because of similarities in voice and measurements and its generally plain plumage. Barrera and Bartels and other ornithologists have suggested that it is most closely related to the probably extinct subspecies G. m. gilesi, but Carantón and Certuche say that it may resemble G. m. milleri more closely than it does gilesi. They suggest that the present species, the brown-banded antpitta, and the Cundinamarca antpitta form a clade.<p>The genus name Grallaria is derived from the Latin word grallae, meaning "stilts", referring to the bird's relatively long legs. The specific name fenwickorum recognises George Fenwick, President of the American Bird Conservancy (ABC), and his family, who assisted Fundación ProAves (ABC's partner organization in Colombia) in the purchase of land, now the Colibrí del Sol Bird Reserve. Based on present knowledge, the antpitta is restricted to the reserve and its immediate surroundings. ProAves's suggested English name also honours Fenwick, while the Spanish common name Tororoi de Urrao is given after the municipality of Urrao, where the bird is found. Tororoi is a general Spanish name used for most antpitta species. The creation of a type specimen without killing an individual follows the policy of the ABC.

Nome scientifico

Grallaria urraoensis

Autorità

Carantón-Ayala & Certuche-Cubillos, 2010

Ordine

Passeriformi

Famiglia

Grallariidae

Genere

Grallaria

Areale e habitat

The known distribution of the bird is limited to the Urrao municipality in and near the Colibrí del Sol Bird Reserve, a 28.52 square kilometres (11.01 sq mi) reserve on the south-eastern slope of the Páramo del Sol massif, at the northern end of the Cordillera Occidental of Colombia, and some 55 kilometres (34 mi) west of Medellín, Colombia's second largest city. The massif has over 27 square kilometres (10 sq mi) of relatively intact páramo and Polylepis woodland, containing more such habitat than all the other páramos in the region combined. There the bird is restricted to upper montane cloud forest dominated by Colombian oak, at an altitude of 2,600 to 3,300 metres (8,500 to 10,800 ft) above sea level, where most territories contain Chusquea bamboo thickets. It is suspected that its range may be larger than currently known, but so far surveys have failed to confirm this.

Migrazione

Resident species

Comportamento

The species exhibits behaviour typical of other members of its genus; it is a shy, terrestrial forager for insects (especially beetles) in the leaf-litter within the forest understorey. It ascends to higher perches (up to 1.5 m above the ground) to sing, and is most active and vocal in the hours following dawn and prior to dusk.<p>It usually occurs in pairs, less often singly, and one group of three has been observed.<p>The males captured in February and March had enlarged testes, typical of breeding birds. The fledgling and an adult with old brood patches were observed in June. These data and song activity from February to April (a dry season) suggest that the breeding season begins early in the year, possibly as early as January, and extends for several months.<p>As in other Grallaria species, the fledgling was less developed than those of most passerines, and both parents fed it earthworms.

Conservazione

The bird has a very restricted known range, limited to the Colibrí del Sol reserve and its immediate vicinity, while previous surveys in similar habitat in the region have failed to record the species. Moreover, habitat used by the bird has been extensively cleared for pasture, and the area is rich in minerals. The known population of 24 territories has an estimated area of 5.8 square kilometres (2.2 sq mi), giving a conservative global population estimate of 57–156 territories. Both articles on the new species propose that the IUCN classify Fenwick's antpitta as critically endangered, and this will be followed in the forthcoming 2011 edition of the BirdLife International list, which is the authority used for birds by the IUCN. Although it is protected in the Colibrí del Sol reserve, it needs further protective measures. The single bird or pair that was known from outside the reserve has not been recorded since mid-2010 and appears to have disappeared.

Tendenza della popolazione

declining