Cyanolyca nanus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Corvidae

Scientific Name: Cyanolyca nanus (Du Bus De Gisignies, 1847)
Common Name(s):
English Dwarf Jay
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.
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.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2c+3c+4c;B1ab(i,ii,iii,iv,v) ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Escalante, P., Navarro, A. & Peterson, A.
Facilitator/Compiler(s): Capper, D., Harding, M., Isherwood, I., Mahood, S., Pople, R., Sharpe, C.J.
This species is considered Vulnerable because it has a small range, which is declining rapidly in response to habitat loss.

Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is known historically from Veracruz adjacent to the border with Puebla and the Sierras Juárez, Aloapaneca and Zempoaltepec in 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 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. in press).

Countries occurrence:
Additional data:
Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:44800
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:6-10Continuing decline in number of locations:Yes
Extreme fluctuations in the number of locations:NoLower elevation limit (metres):1400
Upper elevation limit (metres):3200
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 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
Additional data:
Number of mature individuals:6000-15000Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:2-100Continuing decline in subpopulations:Yes
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

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. in press), 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

Threats [top]

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).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
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).

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. 2016. Cyanolyca nanus. The IUCN Red List of Threatened Species 2016: e.T22705672A94029909. . Downloaded on 17 October 2017.
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