Data for Montane-breeding Bird Distribution and Abundance across National Parks of Southwestern Alaska, 2004-2008

We originally evaluated 14 fine-scale habitat classifications recorded by observers at each site as the basis of our habitat assessment, but models were often overfit and unable to be extrapolated to unsurveyed areas, so we standardized habitat classes between observed habitat types and the 2011 National Land Cover Database (NLCD) for Alaska (Homer et al. 2015). Correlation among observed fine-scale habitats and the NLCD were low. Because certain habitat types (e.g., grass, ice and snow) were rare and structurally similar to more common habitats (e.g., dwarf shrub, bare ground), we combined these habitats with others in the NLCD to reach seven coarse-scale habitats: Baresnow (bare ground and perennial ice and snow), Dshrubherb (mesic herbaceous cover and shrub cover <20 cm in height), Shrub (shrub cover >20 cm and <5 m in height), Dec (deciduous forest), Mixed (mixed deciduous–needleleaf forest), Spruce (needleleaf forest consisting of white, black or Sitka spruce), and Water (emergent and woody wetlands and open water types including turbid and clear water).