Frequency and Distribution of Birds within Forested Wetlands – Breeding and Wintering Seasons

F. M. Smith, The Center for Conservation Biology
B D. Watts, The Center for Conservation Biology

Abstract

The life histories of approximately 350 bird species bring them to the Virginia portion of the Mid-Atlantic Coastal Plain, with nearly 180 species breeding within this region. The Mid-Atlantic Coastal Plain is the northern limit for many “southern” species, and the southern range limit for many “northern” species (Watts 1999). Many species of high conservation concern occupy Coastal Plain forested wetlands and adjacent marsh habitats (Watts 1999, Virginia Dept. of Game and Inland Fisheries 2005, North American Bird Conservation Initiative 2016). Recent declines in songbird populations have led to an increase in management and conservation efforts (Robinson et al. 1987, Suarez et al. 1997, Hunter et al. 2001, Lanham et al 2002, Sauer et al. 2013). The Center for Conservation Biology surveyed a total of 10 study sites three times during the summer of 2016 and the winter season of 2016-2017. These counts, consisting of area search and unlimited radius point count techniques, were used to measure frequency, occurrence, and species richness within select habitat patches in breeding and wintering habitats. . Habitats sampled during the two seasons include forested wetlands (from the headwaters of the wetland to the transition zone, characterized in general by mature hardwood forest), transition zone wetlands (from forested wetland edge to the edge of open marsh habitat, characterized by dense shrubby fringing habitat and an understory of freshwater marsh plants), and upland edge habitats along both headwater and transition wetlands (characterized by drier habitat dominated by pine and oak species). Aerial insectivores were recorded as utilizing the habitat that they were foraging over, while flyover species were simply recorded for presence/absence and not associated with habitat type. A total of 1,036 detections of 72 bird species were made during the breeding and wintering surveys, comprised of 29 neotropical migrant species, 24 temperate migrant species, and 18 non-migratory (resident) species. During the breeding season, a total of 626 birds of 49 species were detected, comprised of 25 neotropical species, 15 resident species, and 9 temperate migrant species. During the winter season, a total of 410 birds of 45 species were detected, comprised of 23 resident species, 17 temperate migrants, and 4 neotropical migrants. Three rounds of playback surveys were used to target the presence or absence of clapper rails during the 2016 breeding season. No clapper rails were detected within the study sites. The species observed during both seasons are typical of those found within the forested wetland habitats of coastal Virginia in the Mid-Atlantic region in both breeding and wintering seasons.