GAP species range data show a coarse representation of the total areal extent of a species or the geographic limits within which a species can be found (Morrison and Hall 2002). To represent these geographic limits, GAP compiled existing GAP data, where available, and NatureServe data (Patterson et al. 2003, Ridgely et al. 2007, NatureServe 2010) IUCN data (IUCN 2004), where needed. Data provided by GAP in collaboration with the Northwest Gap Analysis Project (NWGAP), the Southwest Regional Gap Analysis Project (SWReGAP), the Southeast Gap Analysis Project (SEGAP), the Alaska Gap Analysis Project (AKGAP), the Hawaii Gap Analysis Project (HIGAP), the Puerto Rico Gap Analysis Project (PRGAP), and the U.S. Virgin Islands Gap Analysis Project (USVIGAP). Web map services for species ranges can be accessed via: http://gis1.usgs.gov/arcgis/rest/services/NAT_Species_Birds http://gis1.usgs.gov/arcgis/rest/services/NAT_Species_Mammals http://gis1.usgs.gov/arcgis/rest/services/NAT_Species_Amphibians http://gis1.usgs.gov/arcgis/rest/services/NAT_Species_Reptiles A table listing all of GAP’s available web map services can be found here:http://gapanalysis.usgs.gov/species/data/web-map-services/ Bird data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy’s Migratory Bird Program, Conservation International’s Center for Applied Biodiversity Science (CABS), World Wildlife Fund US, and Environment Canada’s WILDSPACE. Mammal data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy’s Migratory Bird Program, Conservation International’s CABS, World Wildlife Fund US, and Environment Canada’s WILDSPACE. Reptile data were provided by the International Union for Conservation of Nature and Natural Resources (IUCN). Amphibian data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe. Once the needed range data were compiled it was intersected with Natural Resource Conservation Service National Watershed Boundary dataset of 12-digit hydrological units for the US (U.S. Geological Survey and U.S. Department of Agriculture, Natural Resources Conservation Service 2009). Range data were attributed with information regarding occurrence/presence, origin, reproductive use, and seasonal use from GAP regional projects (SWReGAP, SEGAP, NWGAP, AKGAP, HIGAP, PRGAP, and USVIGAP), NatureServe data, and IUCN data. GAP used the best information available to create these species ranges; however GAP seeks to improve and update these data as new information becomes available. These species range data provide the biological context within which to build our species distribution models. Recommended citation: U.S. Geological Survey Gap Analysis Program (USGS-GAP). [Year]. National Species Ranges. Available: http://gapanalysis.usgs.gov. Accessed [date].
