Gymnorhinus cyanocephalus
| Kingdom |
Phylum |
Class |
Order |
Family |
| ANIMALIA |
CHORDATA |
AVES |
PASSERIFORMES |
CORVIDAE |
| Scientific Name: |
Gymnorhinus cyanocephalus |
| Species Authority: |
Wied, 1841 |
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Common Name/s:
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Assessment Information
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| Red List Category & Criteria: |
Vulnerable
A2bc+3bc+4bc
ver 3.1
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| Year Published: |
2012 |
| Assessor/s: |
BirdLife International |
| Reviewer/s: |
Butchart, S. & Symes, A. |
| Contributor/s: |
Benford, R., Inigo, E., Rosenberg, K. & Wells, J. |
Justification:
This species is listed as Vulnerable because of evidence for rapid population declines, presumably as a result of the conversion and degradation of its pinyon-juniper woodland habitat.
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| History: |
| 2008 |
– |
Vulnerable
|
| 2004 |
– |
Vulnerable
|
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Geographic Range
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| Range Description: |
Gymnorhinus cyanocephalus is a permanent resident of the foothills and lower mountain slopes of the western and south-western U.S.A. and northern Baja California, Mexico. In the U.S.A., it is found from central Oregon east to western South Dakota and south to central New Mexico and western Oklahoma. In years when pine crops fail it becomes irruptive, with individuals often dispersing far outside their normal range (Madge and Burn 1993, Balda 2002). Owing mainly to habitat loss, this species is estimated to have suffered a population decline of 36.9% per decade since 1966 (and 59% per decade between 1993 and 2002), but these estimates are unreliable owing to small sample sizes (Sauer et al. 2003, J. Wells in litt. 2003).
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| Countries: |
Native: Mexico; United States
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| Range Map: |
Click here to open the map viewer and explore range. |
Population
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| Population: |
Rich et al. (2003).
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| Population Trend: |
Decreasing
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Habitat and Ecology
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| Habitat and Ecology: |
This species is a highly social cooperatively-breeding bird, forming permanent flocks of typically 250 individuals (Madge and Burn 1993), but which may number over 500 (Balda 2002). Many birds spend their entire lives in their natal flocks, and individuals that do disperse (mostly young females) generally travel short distances. Dispersal habits are affected by changes in local habitat, and by fluctuating operational sex ratios within and among flocks (R. Benford in litt. 2012). Although omnivorous, it has a mutualist relationship with the pinyon pine of western North America, dispersing the large wingless seeds long distances and reaping the reward of an energy and nutrient rich food source. Individuals have excellent spatial memories, giving them uncanny recovery accuracy when digging up food stores months after caching, even through snow. It is one of the earliest nesting passerines in the U.S.A., commencing breeding in the winter in areas where the pine-seed crop was abundant the previous autumn. One population in New Mexico breeds in autumn when pinyon pine cone crops are available (Balda 2002).
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| Systems: |
Terrestrial |
| Major Threat(s): |
The major threat to this species is the destruction of its major habitat type, pinyon-juniper woodland. Land managers have followed a policy to eradicate this woodland, with the U.S. Forest Service classifying it as "non-commercial" and placing it in a "no-value" category. During the 1940s-1960s, major programmes to eradicate the entire habitat were carried out, during which possibly millions of G. cyanocephalus died owing to habitat destruction. Currently herbicides, mechanical ploughing and fire are used to turn pinyon-juniper woodland into pasture land for cattle. Fire-suppression policies in south-west U.S.A. have led to huge, uncontrolled wildfires that consumed large areas of suitable habitat in the late 1990s (Balda 2002). A "catastrophic" drought in the early 2000s also caused considerable mortality (Benford 2008). The decline of pinyon pine and associated encroachment of juniper associated with global warming are primary factors restricting habitat and limiting reproductive success (R. Benford in litt. 2012).
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Conservation Actions
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| Conservation Actions: |
Conservation Actions Underway
No new policies are in place, whilst old ones are no longer implemented (Balda 2002).
Conservation Actions Proposed
Identify suitable areas of pinyon-juniper habitat for protection. Promote suitable land-management practices. Encourage land-owners to take advantage of funding opportunities to create, restore and maintain suitable habitat on their land. Reclassify high-quality, contiguous patches of pinyon juniper woodland as ecologically valuable and protected; most Pinyon Jay habitat is on public land, and management plans focused on preserving this forest are essential (R. Benford in litt. 2012).
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