Populations of Rusty Blackbirds (Euphagus carolinus) have been declining steadily for nearly a century, with the steepest declines occurring over the past few decades. Potential causes of these declines include habitat loss and degradation on breeding grounds, migration stop-over sites, and wintering areas; competition with other blackbird species, increased nest mortality associated with timber harvesting; and impacts of parasites and contaminants. In New Hampshire, Rusty Blackbirds have disappeared from several historic breeding sites. However, surveys conducted in 2006 and 2008 confirmed that this species still breeds in several sites throughout the historic breeding range, from the White Mountains to the Canadian border.
Surveys in 2009 focused on sites in the White Mountain National Forest, where Rusty Blackbirds were documented at seven of 47 survey points, located in five different sites. Four of these sites were historic breeding areas, and one was documented for the first time this year. Habitat characteristics of occupied sites in the White Mountain National Forest were similar to other occupied sites throughout the state. However, occupied wetlands were well below 2500 ft. in elevation, and therefore situated in primarily mixed and deciduous forests, rather than spruce-fir dominated landscapes. Future surveys will focus on wetlands above 2500 ft. to determine if Rusty Blackbirds still inhabit historic breeding sites in spruce-fir habitat.
Project Report: Investigating Rusty Blackbird Breeeding Habitat in NH