|Scientific Name:||Cyanolyca nanus (Du Bus de Gisignies, 1847)|
Cyanolyca nana (Du Bus de Gisignies, 1847) [orth. error]
|Taxonomic Source(s):||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.|
Cyanolyca armillata and C. quindiuna (del Hoyo and Collar 2016) were previously lumped as C. armillata following SACC (2005 & updates), Sibley & Monroe (1990, 1993) and Stotz et al. (1996).
|Identification information:||20-23 cm. Small, slender and agile, blue jay. Slate-blue except for black mask bordered by slight, whitish supercilium and whitish throat highlighted by diffuse breast-band. Voice Repeated two-syllable, high-pitched nasal yeeyip yeeyip. Occasionally also longer, harsh squawk. Hints Often accompanies mixed-species flocks with Grey-barred Wren Campylorhynchus megalopterus.|
|Red List Category & Criteria:||Vulnerable A2c+3c+4c ver 3.1|
|Contributor(s):||Escalante, P., Navarro, A., Peterson, A. & Martínez-Morales, M.|
|Facilitator/Compiler(s):||Capper, D., Harding, M., Isherwood, I., Mahood, S., Pople, R., Sharpe, C.J., Westrip, J.|
This species is considered Vulnerable because it is believed to be declining rapidly in response to habitat loss.
|Previously published Red List assessments:|
|Range Description:||This species is known historically from central Veracruz adjacent to the border with Puebla and the Sierras Juárez, Aloapaneca and Zempoaltepec in northern Oaxaca south-east Mexico. It was feared extinct throughout this range except for the Cerro San Felipe in the Sierra Aloapaneca, where it remains quite common. However, it is now known to be more widespread. There are records from Tangojó in extreme east Querétaro, north-east Hidalgo, central Veracruz and La Chinantla in north Oaxaca, and it may be locally common where suitable habitat persists (M. Angel Martínez, E. Ruelas and R. Sanchez pers. comm. to A. G. Navarro in litt. 1998, A. G. Navarro in litt. 1998, Rojas-Soto et al. 2001, Martínez-Morales 2004).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||In Hidalgo the population density has been estimated at 4.4 individuals per km2 (M. Martínez-Morales in litt. 2016). Assuming that this is representative and that only a proportion of its range is occupied, this would equate to a population of c.4,100 individuals; roughly equating to 2,750 mature individuals.|
Trend Justification: No quantitative data are available for the calculation of population trends; however, the species is suspected to be declining rapidly in line with habitat degradation within its range.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||It has been observed in several humid montane forest-associations, but most abundantly in pine-oak-fir associations and areas with an even mix of pine and oak. Laurel and abundant epiphytic growth are characteristic of these associations. Lower densities occur in oak-dominated forest, and its occurrence in secondary growth depends on the predominance of the preferred tree-associations and nearby tracts of primary forest. Suitable breeding habitat has a sufficiently open canopy to allow the development of a dense subcanopy. It forages mostly from the lower subcanopy to the higher shrub layer, where it gleans invertebrates from and around epiphytes. It occurs at elevations of 1,400-3,200 m (Rojas-Soto et al. 2001), but only above 1,670 m in the centre and south of its range. This is plausibly a natural altitudinal distribution, but it may have been extirpated from the lower elevations in the south of its range. The breeding season begins at Cerro San Felipe in early April.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||6.7|
|Movement patterns:||Not a Migrant|
|Major Threat(s):||Logging, agricultural expansion, firewood-gathering, road and tourist developments, sheep-ranching, intense grazing and intensive urbanisation have resulted in extensive and continuing destruction and fragmentation of its habitat (Dinerstein et al. 1995). It is prone to nest-desertion following human disturbance, suggesting that there are few predators of adult birds. The continuing spread of West Nile virus is not thought to pose a serious threat, and no related mortality has been detected in this species (P. Escalante in litt. 2005). Climate change is also expected to be an additional factor of habitat loss (Ponce-Reyes et al. 2012).|
Conservation Actions Underway
There are two protected areas within the species's range: Sierra Gorda Biosphere Reserve and Benito Juárez National Park. Cerro San Felipe is officially within Benito Juárez National Park, but the boundaries of this relatively small reserve have never been demarcated (Salas et al. 1994) and it offers the species little protection (A. T. Peterson in litt. 1998). Additionally, eight voluntarily destined areas for conservation have been created in north Oaxaca: San Juan Teponaxtla Communal Ecological Reserve Zone, San Antonio del Barrio Conservation Area, San Pedro Tlatepusco conservation Area, San Felipe de León Conservation Area, Tierra del Faisán Conservation Area, Nopalera del Rosario Conservation Area, Santo Domingo Cacalotepec Communal Conservation Zone, and La Cruz-Corral de Piedra (http://www.conanp.gob.mx/que_hacemos/areas_certi.php) (M. Martínez-Morales in litt. 2016).
Conservation Actions Proposed
Survey to assess more precisely the extent of its distribution. Demarcate and effectively protect the boundaries of Benito Juárez National Park. Protect sites where the species has been recently recorded.
|Citation:||BirdLife International. 2017. Cyanolyca nanus. The IUCN Red List of Threatened Species 2017: e.T22705672A117183117.Downloaded on 13 December 2017.|
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