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Aphelocoma coerulescens
– Vulnerable
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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AVES
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Order:
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PASSERIFORMES
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Family:
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CORVIDAE
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Scientific Name:
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Aphelocoma coerulescens
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Species Authority:
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(Bosc, 1795)
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Common Name/s:
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| English | — | FLORIDA SCRUB-JAY |
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Assessment Information
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Red List Category & Criteria:
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VU B1ab(i,ii,iii,iv,v); C1+2a(i) ver 3.1 (2001)
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Year Assessed:
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2004
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Assessor/s:
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BirdLife International
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Evaluator/s:
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Capper, D., Wege, D. & Pople, R. (BirdLife International Red List Authority)
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Justification:
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This species qualifies as Vulnerable because it has a small and fragmented population and range, which continues to decline as a result of urban development and human disturbance.
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History:
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| 2000 | - | Vulnerable (BirdLife International 2000) |
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Geographic Range
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Range Description:
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Aphelocoma coerulescens was known from scattered localities in 39 of 40 peninsula counties in Florida, USA, but has declined since the mid-19th century and most rapidly since 1950. The current range is local and fragmented from Flagler, Marion and Levy counties to Collier, Glades and Palm Beach. The breeding population was 4,000 pairs in 1993. As the average group size is three, total numbers were probably c.10,000, a c.25% decline since 19834,5.
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Range Map:
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 (click for detailed map)
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Countries:
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Native:
Mexico; United States
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Population
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Population Trend:
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Habitat and Ecology
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Habitat and Ecology:
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It is entirely restricted to scrub and shrubby flatwoods (a xeromorphic shrub community dominated by a layer of oaks Quercus spp. rarely more than 2 m high). Ground cover is sparse with bare sand patches for foraging and acorn-caching. It rarely uses scrub with more than 15% pine cover. Habitat structure and composition are maintained by frequent fires, and optimal habitat occurs 5-15 years post-fire. It is permanently territorial and territory size is not significantly compressible except through artificial feeding. Dispersal is inhibited by more than 8 km of open, non-scrub habitat or 1 km of forest. First brood eggs are laid from March-May, and true second brood attempts are rare. It feeds mainly on arthropods, acorns and small vertebrates4,5.
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System:
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Terrestrial
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Threats
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Threats:
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Housing developments and citrus-groves have replaced much suitable habitat5. The rate of development in Florida has increased markedly since the 1960s as the human population almost doubled between 1960 and 19802. Direct human disturbance and feral cats affect the increasing number of territories adjacent to housing2, and birds in roadside territories are frequently killed by vehicles3,6. Fire suppression causes scrub to overgrow and pine density to increase, rendering habitat unsuitable. Several species of snake, bird and mammal are native predators4. The recent spread of West Nile virus to Florida may pose a threat to the species8.
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Conservation Actions
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Conservation Actions:
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Conservation measures underway:
The species has been studied since 1969 and this continues, especially at and near the Archbold Biological Station4,5. There are now four populations of colour-banded jays that are monitored7. Habitat management by burning is still too site-specific7.
Conservation measures proposed:
Monitor the population4,5. Regularly determine the extent of habitat4,5. Research the causes of variation in birth rates, death rates, and spatial/temporal movement patterns, in both natural and human-modified habitats4,5. Maintain the long-term ecological study4,5. Acquire and actively manage a protected-area network4,5. Burn patches of habitat every 8-15 years4,5.
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