Justification 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.

Family/Sub-family Corvidae

Species name author (Bosc, 1795)

Taxonomic source(s) AOU checklist (1998 + supplements), Sibley and Monroe (1990, 1993), Stotz et al. (1996)

Identification 27-31 cm. Medium-sized, blue and grey jay with long tail. Adults have blue wings, tail and head with white supercilium and black facial patch, grey mantle, whitish underparts, black legs and bill. Juvenile similar with blue in head replaced by brown tinged grey. Similar spp. Blue Jay Cyanocitta cristata in flight, but has white in wings and tail. Voice Variety of calls, with marked variation locally even over short distances, including rasping creep and sweet, loose ch-leep. Hints Most easily found by voice as noisy groups move furtively from bush to bush.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

8,000

decreasing

6,900 km²

Yes

Range & population 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 1983^4,5. Declines are believed to have continued and the current best estimate places the global population at c.6,500 individuals¹⁰.

Ecology: 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; territory size is often decreased owing to habitat fragmentation resulting in increased predation and reduced reproductive success. 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. Some nests benefit from helpers, which increase reproductive success⁹. It feeds mainly on arthropods, acorns and small vertebrates^4,5.

Threats 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. Fire suppression in remaining habitat has been identified as a major continuing threat because it causes scrub to overgrow and pine density to increase, rendering habitat unsuitable. Direct human disturbance and feral cats affect the increasing number of territories adjacent to housing². Birds in roadside territories are frequently killed by vehicles^3,6. 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.

Conservation measures underway The species has been studied since 1969 and this continues, especially at and near the Archbold Biological Station^4,5. 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 population^4,5. Regularly determine the extent of habitat^4,5. Research the causes of variation in birth rates, death rates, and spatial/temporal movement patterns, in both natural and human-modified habitats^4,5. Maintain the long-term ecological study^4,5. Acquire and actively manage a protected-area network^4,5. Burn patches of habitat every 8-15 years^4,5.

References 1. AOU (1998). 2. Cox (1987). 3. Dreschel (1990). 4. Woolfenden and Fitzpatrick (1996). 5. G. E. Woolfenden in litt. (1998). 6. Mumme et al. (2000). 7. R. Bowman in litt. (2003). 8. Chu et al. (2003). 9. Franzreb (2007). 10. G. Butcher in litt. (2007).

Further web sources of information

Audubon WatchList

U.S. Fish and Wildlife Service - Recovery Plan

Text account compilers Jeremy Bird (BirdLife International), David Capper (BirdLife International), Matt Harding (BirdLife International), Rob Pople (BirdLife International), David Wege (BirdLife International)

Contributors Reed Bowman (Archibold Biological Station, Florida), Greg Butcher (National Audubon Society), G.E Woolfenden (University of South Florida)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International), Mike Crosby (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Aphelocoma coerulescens. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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