Swainson’s Thrush is a medium sized (15-18cm) thrush which prefers to breed in dense shrub growth associated with spruce-fir forests. The "russet-backed" race prefers mixed forests and deciduous riparian woodlands of the coastal region from British Columbia, to northern California. These Pacific populations winter in mature tropical and secondary forests of Central America, whereas the "olive-backed" race that breeds in the Boreal and Rockies winters in S. America.
Models of Monitoring Avian Productivity and Survival (MAPS) demographic data and high-resolution land cover data showed that Swainson’s Thrush prefers large intact forest patches with low perimeter to area ratios.
1.06432-(0.000119 * "gtopo30") - ( "pnr_lat_grid"* 0.013561) - (0.00219 * "nlcd01cc2k") - (0.000285 * "strmnet5k")
Definitions of these parameters and how they were derived can be found in