Bicknell's Thrush Point Count Surveys in Cordillera Septentrional, Dominican Republic, 2010

The winter range of Bicknell's Thrush (Catharus bicknelli), a globally Vulnerable Nearctic-Neotropical migratory songbird, is restricted to the Greater Antilles. Most birds occur on Hispaniola, where the species exhibits sexual habitat segregation, and loss of its preferred wet broadleaf habitats has been severe. Conservation of female-dominated habitats has been identified as a top priority. During 2010, we conducted standardized field surveys for Bicknell's Thrush in forests of the Dominican Republic's Cordillera Septentrional, an area of high importance for females. We used a generalized random tessellation stratified (GRTS) sampling design to allow for a spatially balanced probabilistic approach. For the GRTS selection process we divided our study area into 1 km2 blocks (n=1,100). We then evaluated each block in the order in which it was selected by GRTS and established survey points if the block: 1) contained enough forested areas to place at least 4 survey points 200 m apart and 2) was within 3 km of an access road or 1 km of a trail. We did not place survey points within blocks that we did not have permission to access. For logistical reasons, we occasionally placed 1 to 2 points in an adjacent block to create a full route of points. This resulted in 25 blocks containing 1 to 12 points.