First record of Turdus ignobilis Sclater , 1857 ( Aves : Turdidae ) in the Andes of Ecuador

We present the first record of the Black-billed Thrush (Turdus ignobilis) in Loja city, Ecuadorian Andes. The bird was recorded in August and September 2015 in Jipiro Park, north of the city, at an elevation of 2,074 m. This increases this species’ altitudinal range in Ecuador by at least 540 m. The presence of the Black-billed Thrush in Loja shows that the valley of the Zamora River allows some species to move from the eastern lowlands to this region of the country.

The Black-billed Thrush (Turdus ignobilis Sclater, 1857) is a passerine bird of medium size (21-24 cm, 44-66 g) that inhabits deforested areas, plantations, forest edges and altered areas.It feeds on insects, worms, caterpillars, fruits and seeds, and is considered an abundant species in its range (Canaday & Jost 1999;Collar & Bonan 2015).Some authors write that this species is restricted in Ecuador to areas below 1,200 m in eastern tropical forests (Ridgely & Greenfield 2006;Collar & Bonan 2015).However, McMullan & Navarrete (2013) proposed that its range is higher, up to 1,500 m (Figure 1).
On 27 August 2015, we photographed a subadult individual of T. ignobilis (Figures 2a, b) in the urban Jipiro Park (03°58ʹ14ʺ S, 079°12ʹ16ʺ W, 2,040 m) north of the city of Loja, Ecuador.Days later, 3 September 2015, the species was recorded again in the same city.On this occasion, two individuals were found in a small group of willows (Salix babylonica), pines (Pinus sp.), eucalyptus (Eucalyptus sp.), and alders (Alnus acuminata).Individuals were observed for longer than 25 minutes.During this time, they were searching for food on the ground, peering between some dry leaves, and quiet, not singing or calling.On several occasions, several male adults of T. fuscater d'Orbigny & Lafresnaye, 1837, a very common species in the area, attacked individuals of T. ignobilis, forcing them to move away.In the same place, there were also present several young individuals of Turdus reevei Lawrence, 1870.They stayed close to T. fuscater and T. ignobilis without disturbing or harming any of them.
The species identification was based on publications of Ridgely & Greenfield (2006) and Schulenberg et al. (2010).In addition, photographs were sent to some members of the Ecuadorian Committee of Ornithological Records (https://ceroecuador.wordpress.com)who corroborated the identification.Photographs (Figures 2a,  b) show that the sighted individuals were grayish brown, with the chest slightly more gray, the belly whitish, and the throat white with some dark stripes.The beak was black and there was no eye ring.However, all individuals lacked the characteristic half-moon on the base of the throat that is diagnostic of T. ignobilis debilis Hellmayr, 1902, the subspecies that inhabits Ecuador (Ridgely & Greenfield 2001;Collar & Bonan 2015).This may be because the photographed individual is subadult and distinctive halfmoon mark requires more time to develop (pers.obs.).
Our record of T. ignobilis from Loja is the first of the species in the Ecuadorian Andes.This record, at 2040 m above sea level, increases this species' altitudinal range in Ecuador by at least 540 m above the upper limit proposed by McMullan & Navarrete (2013) and 840 m by that proposed by Ridgely & Greenfield (2006) and Collar & Bonan (2015) (Figure 1).It also expand the known range of T. ignobilis by more than 50 km west of the tropical forests of southeastern Ecuador, where the city of Zamora is located.
The city of Loja is located in a depression surrounded by mountains known as Hoya de Loja; these mountains have an altitude of 2,500-2,700 m in the south and west to 2,900-3,100 m in the north and east.Two major rivers cross the city: Zamora (east) and Malacatos (west).Some forests, Andean thickets, and plantations of exotic trees (Eucalyptus sp., Pinus sp., Cupressus sp.), are present around Loja city and along the Zamora and Malacatos rivers.Both rivers originate from Podocarpus National Park and run north to merge at the city center.Downstream from this confluence, the river keeps the name of Zamora River, which passes through the eastern flank of the Hoya  field, members of the Ecuadorian Committee of Ornithological Records (https://ceroecuador.wordpress.com/) for helping to corroborate the identification of T. ignobilis.

LITERATURE CITED
de Loja.From there, the river runs eastward, toward the city of Zamora.Given this relief, the valley of the Zamora River is the only possible way for T. ignobilis to reach Loja from the humid tropical forests of southeastern Ecuador.Flying over the 2,900-3100 m high mountain range to access the Central Andes seems less probable.
Our record of T. ignobilis in the city of Loja helps to understand the range and mobility of birds in the southern Ecuadorian Andes, little known to date and heavily influenced by geographical features (Krabbe 2008).Compared to the north region, ranges of the southern Ecuadorian Andes are more scattered, lack of a clear orientation, and are lower in elevation (Winckell 1982).This allows birds to penetrate in some areas of the southern Ecuadorian Andes and their distribution is more difficult to explain.
We recorded Turdus ignobilis in a novel ecosystem.This species is considered uncommon to locally common in eastern tropical forests of Ecuador (Ridgely & Greenfield 2006).However, our record was in an altered habitat dominated by exotic tree species, mainly Pinus sp., Eucalyptus sp., and Cupressus sp, and surrounded by shrubs and evergreen forests in the Hoya de Loja.The closest documented records of T. ignobilis are from the Bombuscaro area (Podocarpus National Park) at about 1,000 m, south of the city of Zamora.There, it is considered a common species according to the literature (Rasmussen & Rabeck 1994;Collar & Bonan 2015) and records posted on eBird and Xeno-Canto (Sullivan et al. 2009;Ordóñez-Delgado 2014).
Our new records show the need to investigate the role of Zamora River, other local rivers, and low-lying areas of mountain ranges as habitat linkages and corridors for birds (Bolger et al. 2001) between the Hoya de Loja and the surrounding areas (e.g., Malacatos or Catamayo valleys).Diversity, ecological tolerance, and the distribution patterns of birds in the southern Ecuadorian Andes might be more reliably determined if knowledge of how birds use corridors through the mountains.Such knowledge would be important for the conservation of the birds of the southern Ecuadorian Andes.

Figure 2 .
Figure 2. Photographs of Black-billed Thrush taken north of the city of Loja: (a) detail of the head, beak, throat and belly, (b) left flank.