Canada Warbler Breeding Population Study

The Canada Warbler migrates to New Hampshire all the way from the eastern slope of the Andes. The North American Bird Conservation Initiative has identified this species as a high priority for Bird Conservation Region 14, the Atlantic Northern Forest. This handsome bird with a melodious song is experiencing a pronounced population decline throughout this area, with trend estimates ranging between -2.4% and -13.2% per year.

Canada warbler’s sparse distribution and secretive breeding habits have confounded past efforts to identify productive habitat and appropriate management techniques. However, survey methods recently developed by Villanova University promise to shed light on the conservation needs of this uncommon and vulnerable species. I will be collaborating with the Vermont Institute of Natural Science (VINS) and Villanova at a new avian research plot in the Canaan Town Forest. This forested wetland, located along the Mascoma River, harbors an unusually high concentration of Canada warblers. Adjacent conservation lands may provide additional opportunities for study.

The project’s primary goal is to compare Canada warbler reproductive success

across a variety of undisturbed and actively managed habitats in New Hampshire and Vermont. Dr. Jameson Chace of Villanova University will coordinate Vermont surveys in the Nulhegan Basin Division of the Silvio O. Conte National Fish and Wildlife Refuge and in Bear Swamp at the Center for Northern Studies. In Canaan, I will work with Dan Lambert of VINS and students from Plymouth State. We will use three measures to determine the value of different habitat types: pairing success (the proportion of territorial males that are mated), hatching success (the number of hatched young per nest), and fledging success (the number of fledged young per nest). We will map male and female habitat use by direct observation and radio telemetry and will employ standardized vegetation sampling techniques to describe the structure and composition of productive territories. Biology students from Plymouth State College will assist in the investigation in order to learn about the scientific method, ornithological field techniques, and principles of conservation biology. When the study is completed, results will be used to develop forest management guidelines that will help ensure the long-term prospects for Canada warblers in the Northeast.