Habitat use and demography of red-headed woodpeckers in west-central Illinois

For the last four decades, red-headed woodpeckers (Melanerpes erythrocephalus) have experienced steep population declines across much of eastern North America. The most pronounced declines have been in the Midwestern U.S. The causes of these declines are not fully understood, but have been attributed to the loss or degradation of preferred habitat, particularly because of changes in land use and management practices. Red-headed woodpeckers have been known to use a variety of habitat types, but little is known about specific habitat features associated with habitat use and reproductive success. During the breeding seasons of 2012 and 2013, I conducted surveys for red-headed woodpeckers and monitored nests to estimate reproductive success at seven sites in west-central Illinois. I detected red-headed woodpeckers at 32% of 502 points surveyed, and occupancy ranged from 0.15 to 0.76 among sites. I found few differences in vegetation structure between points where red-headed woodpeckers were detected relative to random points. Relative to randomly selected points, nest sites were characterized by greater abundance of large trees, snags, and dead limbs. Nest survival varied little among sites, but appeared to be greater for higher cavities, nests located in floodplain forest, and at nest sites surrounded by relatively little shrub cover. My results suggest that red-headed woodpeckers use a variety of available habitats on the modern Midwestern landscape, and will nest in areas with an open understory and dead limbs and snags, especially large snags, and reproduce successfully in a range of habitat conditions