Replication Data for Associations between elevation, introduced red squirrels, and boreal bird distributions on Newfoundland

Elevational gradients in boreal forest songbird assemblages have received limited attention but may have important conservation implications in the face of climate-change induced habitat alteration and shifts in predator communities. Our objectives were (1) to examine the role that elevation plays in the distribution of individual species, (2) to identify bird species for which occupancy rate was correlated with squirrel probability of occurrence, and (3) to investigate the influence of elevation and red squirrel occurrence on the species richness of different nesting guilds. We completed 1,960 point count surveys for birds and red squirrels over two years across a 257 km2 study area in western Newfoundland, Canada, that spanned southern boreal to northern boreal bioclimatic zones (75-610 m elevation).