|Scientific Name:||Aphelocoma coerulescens|
|Species Authority:||(Bosc, 1795)|
|Taxonomic Notes:||~3000 family groups (~9000 birds) (Boughton and Bowman 2011).|
|Red List Category & Criteria:||Vulnerable A2cde+3cde+4cde;B1ab(i,ii,iii,iv,v);C1+2a(i) ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
|Contributor/s:||Bowman, R., Breininger, D., Butcher, G. & Woolfenden, G.|
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 habitat loss and degradation, largely as a result of fire suppression.
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, but has continued to decline by >25% since then (Boughton and Bowman 2011) and is now estimated at c.3,000 family groups (Boughton and Bowman 2011, R. Bowman in litt. 2012). In many areas, average group size is below three, thus the global population is suspected to be 6,000-9,000 individuals.
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The breeding population was 4,000 pairs in 1993 (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998), but has decline by >25% since then (Boughton and Bowman 2011) and is now estimated at c.3,000 family groups (R. Bowman in litt. 2012). In many areas, average group size is below three, thus the global population is suspected to be 6,000-9,000 individuals, roughly equivalent to 4,000-6,000 mature individuals.|
|Habitat and Ecology:||
It is entirely restricted to scrub and shrubby flatwoods (a xeromorphic shrub community dominated by a layer of oak 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. Fire frequency for coastal scrub should be greater than that for inland scrub as open sandy areas do not persist in coastal areas for more than a few years (D. Breininger in litt. 2012). It is permanently territorial, with habitat fragmentation decreasing territory size and 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 success (Franzreb 2007). It feeds mainly on arthropods, acorns and small vertebrates (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998).
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. Declines on lands specifically protected for the species are largely the result of reduced habitat quality, caused by disrupted fire regimes (Breininger et al. 1999, 2006, 2009, 2010). In addition, extensive habitat fragmentation has led to a high degree of genetic differentiation (Coulon et al. 2008) and additional land protection to increase connectivity within existing genetic units is likely necessary to prevent further fragmentation and loss of genetic diversity (Coulon et al. 2010, 2012). Housing developments and citrus-groves have replaced much suitable habitat (G. E. Woolfenden in litt. 1998). The rate of development in Florida has increased markedly since the 1960s as the human population almost doubled between 1960 and 1980 (Cox 1987). Direct human disturbance and feral cats affect the increasing number of territories adjacent to housing (Cox 1987). Birds in roadside territories are frequently killed by vehicles (Dreschel et al. 1990, Mumme et al. 2000). Several species of snake, bird and mammal are native predators (Woolfenden and Fitzpatrick 1996). Nocturnal predators, including yellow rat snakes Elaphe obsoleta, are a particular threat since breeding birds do not appear to be vigilant to, or defend against, nocturnal predators and brooding females are also at risk from being killed (Carter et al. 2007). Hatching failure has been linked to below-average rainfall during the breeding season (Wilcoxen et al. 2011) and so droughts are likely to pose a threat to the species. The recent spread of West Nile virus to Florida may pose a threat to the species (Chu et al. 2003). An observation of nest-predation by invasive fire ants Solenopsis invicta was reported in south-central Florida in 2009 (Wilcoxen and Rensel 2009) and may be a threat to the reproductive success of the species. Climate change may pose a threat to the species.
Conservation Actions Underway
The species has been studied since 1969 and this continues, especially at and near the Archbold Biological Station (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998). A long-term study at Kennedy Space Center has been running for >20 years, focusing on linking demography to habitat management decision making (e.g. Breininger et al. 2009). A species recovery plan was published in 1990 (U.S. Fish and Wildlife Service 1990) and the species is included in the Multi-Species Recovery Plan for South Florida (1999). There are now four populations of colour-banded jays that are monitored (R. Bowman in litt. 2003). Habitat management by burning is still too site-specific (R. Bowman in litt. 2003). Supplementary feeding at Archbold Biological Station in south-central Florida from 2000 to 2007 resulted in a marked improvement of reproductive output (Schoech et al. 2008) which has potential impacts for local populations as well as potential translocated populations.
Conservation Actions Proposed
Monitor the population (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998). Regularly determine the extent of habitat (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998). Research the causes of variation in birth rates, death rates, and spatial/temporal movement patterns, in both natural and human-modified habitats (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998). Maintain long-term ecological studies (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998, Breininger et al. 2009). Acquire and actively manage a protected-area network (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998). Burn patches of habitat based on habitat states and predicted trajectories (Woolfenden and Fitzpatrick 1996, G. E. Woolfenden in litt. 1998, Breininger et al. 2010).
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
Boughton, R. and Bowman, R. 2011. State wide assessment of Florida Scrub-Jay on managed areas: A comparison of current populations to the results of the 1992-93 survey. Report to USFWS.
Breininger, D. R., J. D. Nichols, B. W. Duncan, E. D. Stolen, G. M. Carter, D. Hunt, J. H. Drese. 2010. Multistate modeling of habitat dynamics: factors affecting Florida scrub transition probabilities. Ecology 9: 3354-3364.
Breininger, D. R., J. D. Nichols, G. M. Carter, D. M. Oddy. 2009. Habitat-specific breeder survival of Florida Scrub-Jays: inferences using multistate models. Ecology 90: 3180-3189.
Breininger, D. R., M. A. Burgman, and B. M. Stith. 1999. Influence of habitat, catastrophes, and population size on extinction risk on Florida Scrub-Jay populations. Wildlife Society Bulletin 27: 810-822.
Breininger, D. R.; Toland, B.; Oddy, D.M.; Legare, M. L. 2006. Landcover characterizations and Florida Scrub-jay (Aphelocoma coerulescens) population dynamics. Biological Conservation 128: 169-181.
Carter, G. M.; Legare, M. L.; Breininger, D. R.; Oddy, D. M. 2007. Nocturnal nest predation: a potential obstacle to recovery of a Florida Scrub-jay population. Journal of Field Ornithology 78(4): 390-394.
Chu, M.; Stone, W.; McGowan, K. J.; Dhondt, A. A.; Hochachka, W. M.; Therrien, J. E. 2003. West Nile file. Birdscope 17: 10-11.
Coulon, A., J W. Fitzpatrick, R. Bowman, and I. J. Lovette. 2012. Mind the gaps: linear increase of genetic differentiation with the size of habitat gaps in Florida Scrub-Jays. Biology Letters (in press).
Coulon, A., J. W. Fitzpatrick, R. Bowman, B. M. Stith, C. A. Makarewich, L. M. Stenzler, and I. J. Lovette. 2008. Congruent population structures identified by dispersal modeling and intensive genetic surveys in the threatened Florida Scrub-Jay (Aphelocoma cœrulescens). Molecular Ecology 17: 1685-1701.
Coulon, A., J. W. Fitzpatrick, R. Bowman, I. J. Lovette. 2010. Effective dispersal decreases with increased habitat fragmentation in the Florida Scrub-Jay: complimentary evidence from direct and indirect dispersal estimates. Conservation Biology 24: 1080-1088.
Cox, J. A. 1987. Status and distribution of the Florida Scrub Jay. Florida Ornithologists Society, Florida, U.S.A.
Dreschel, T. W, Smith,R. B. and Breininger, D. R. 1990. Florida Scrub Jay mortality on roadsides. Florida Field Naturalist 18: 82-83.
Franzreb, K. E. 2007. Reproductive success and nest depradation of the Florida Scrub-jay. Wilson Journal of Ornithology 119(2): 162-169.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Johnson, F. A., D. R. Breininger, B. W. Duncan, J. D. Nichols, M. C. Runge, B. K. Williams. 2011. A Markov decision process for managing habitat for Florida Scrub-Jays. Journal of Fish and Wildlife Management 2: 234-2470.
Mumme, R.L., Schoech, S.J., Woolfenden, G.W. and Fitzpatrick, J.W. 2000. Life and death in the fast lane: demographic consequences of road mortality in the Florida scrub-jay. Conservation Biology 14(2): 501-512.
Schoech, S. J.; Bridge, E. S.; Boughton, R. K.; Reynolds, S. J.; Arwell, J. W.; Bowman, R. 2008. Food supplementation: a tool to increase reproductive output? A case study in the threatened Florida Scrub-jay. Biological Conservation 141(1): 162-173.
U.S. Fish and Wildlife Service. 1990. Florida Scrub Jay recovery plan.
U.S. Fish and Wildlife Service. 1999. South Florida Multi-species recovery plan. Atlanta, Georgia.
Wilcoxen, T. E.; Bridge, E. S.; Boughton, R. K.; Rensel, M. A.; Reynolds, S. J.; Schoech, S. J. 2011. Parental, social and environmental factors associated with hatching failure in Florida Scrub-jays Aphelocoma coerulescens. Ibis 153(1): 70-77.
Wilcoxen, T. E.; Rensel, M. A. 2009. Invasive fire ants depredate nest of Florida Scrub-jay. Wilson Journal of Ornithology 121(4): 846-847.
Woolfenden, G. E.; Fitzpatrick, J. W. 1996. Florida Scrub-Jay (Aphelocoma coerulescens). In: Poole, A.; Gill, F. (ed.), The birds of North America, No. 228, pp. 1-28. The Academy of Natural Sciences, and The American Ornithologists' Union, Philadelphia, and Washington, DC.
|Citation:||BirdLife International 2012. Aphelocoma coerulescens. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 25 May 2013.|
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