This indicator is an index of habitat suitability for twelve upland hardwood and forested wetland bird species based on patch size and other ecosystem characteristics such as proximity to water and proximity to forest and ecotone edge.
Reason for Selection
This index represents a variety of ecosystem features and is already being modeled and monitored for the entire region by the Atlantic Coast Joint Venture. The needs of these forest bird species are increasingly restrictive at higher index values, reflecting better quality habitat.
Input Data
– Southeast GAP species models:
Chuck-will’s widow (bCWWI)Red-headed woodpecker (bRHWO)Wood Thrush (bWOTH)Whip-poor-will (bWPWI)American Woodcock (bAMWO)Hooded Warbler (bHOWA)Kentucky Warbler (bKEWA)Acadian Flycatcher (bACFL)Black-throated green warbler (bBTNW)Northern parula (bNOPA)Prothonotary warbler (bPROW)Swainson’s warbler (bSWWA)
– Select models from the South Atlantic Migratory Bird Initiative (SAMBI) Designing Sustainable Landscapes (DSL) avian habitat project:
Prothonotary warbler (bPROW)Swainson’s warbler (bSWWA)
Mapping Steps
The index of forest birds is based on scores representing increasingly restrictive limitations of potential habitat for a suite of species. Species-based constraints are:
1) If a pixel was identified in the wood thrush (1 ha minimum patch), whip-poor-will (no more than 250 m into forest interior), red-headed woodpecker (interior patch within 500 m of early successional habitat), Chuck-will’s widow (interior patch within 500 m of early successional habitat), or American woodcock (within 125 m of ecotone edge) Southeast GAP models, it was given a value of 1. If not, it was given a value of 0.
2) If a pixel was identified in the hooded warbler (15 ha minimum patch) or Kentucky warbler (17 ha minimum patch in wet hardwoods) Southeast GAP models, it was given a value of 2. If not, it retained the value from step 1.
3) If a pixel was identified in the Acadian flycatcher (40 ha minimum patch) Southeast GAP model, it was given a value of 3. If not, it retained the value from step 2.
4) If a pixel was identified in the Northern parula (70 ha minimum patch) Southeast GAP model, black-throated green warbler (100 ha minimum patch) Southeast GAP model, or the Prothonotary warbler (70 ha minimum patch within 120 m of water) Southeast GAP or DSL model, it was given a value of 4. If not, it retained the value from step 3.
5) If a pixel was identified in the Swainson’s warbler (350 ha minimum patch within 250 m of water) Southeast GAP or DSL model, it was given a value of 5. If not, it retained the value from step 4.
Final indicator values
The resulting index appears below:
5 = Potential for additional presence of Swainson’s warbler (high)
4 = Potential for additional presence of Northern parula, black-throated green warbler, or Prothonotary warbler
3 = Potential for additional presence of Acadian flycatcher
2 = Potential for additional presence of hooded warbler or Kentucky warbler
1 = Potential for presence of wood thrush, whip-poor-will, red-headed woodpecker, Chuck-will’s widow, or American woodcock
0 = Less potential for presence of forest bird index species (low)
Known Issues
–This indicator predicts less habitat for Swainson’s warbler and prothonotary warbler in the Apalachicola basin because one of the two models used for these species (DSL) does not cover this area.
– This indicator overpredicts habitat in areas that have been converted since the release of 2001 GAP landcover data.
– Thresholds used in this indicator focus primarily on species presence and larger patches are likely needed for source populations of any of these species.
Disclaimer: Comparing with Older Indicator Versions
There are numerous problems with using South Atlantic indicators for change analysis. Please consult Blueprint staff if you would like to do this (email hilary_morris@fws.gov).
Literature Cited
Southeast Gap Analysis Project. SE-GAP Vertebrate Predicted Habitat. [http://www.basic.ncsu.edu/segap/DataServer.html].
Williams SG, Rubino MJ. 2012. Designing Sustainable Landscapes Project. Biodiversity and Spatial Information Center, North Carolina State University. Available: http://www.basic.ncsu.edu/dsl/hab.html (April 2014).
Williams SG, Rubino MJ, Silvano AL, Elliott MJ, Cook K, Smith S. 2010. Southeast Gap Analysis Project. Biodiversity and Spatial Information Center, North Carolina State University; Alabama Gap Project, Alabama Cooperative Fish & Wildlife Research Unit, Auburn University; Natural Resources and Spatial Analysis Laboratory, University of Georgia. Available: http://www.basic.ncsu.edu/segap/ (April 2014).
