A study of winter waterfowl ecology at Port Joli

This study was carried out in and near the Port Joli Bird Sanctuary, on the South Shore of Nova Scotia, between October, 1967, and June, 1969. The primary objectives of the study were to determine the food habits of the waterfowl; to assess the availability and utilization of waterfowl foods; to determine waterfowl numbers, past and present, and their movements; and to assess the effects of weather, tide, and other environmental factors on the waterfowl populations. Data were obtained on all of the above factors and are reported in the thesis. The principal food of Canada geese (Branta canadensis) was the leaves and rhizomes of eelgrass, Zostera marina. The chief fall foods of black ducks (Anas rubripes) were the Gastropods Littorina littorea and Nassarius obsoletus; while the main winter foods were Littorina littorea and L. obtusata. The primary food of common goldeneye (Bucephala clangula) and scaup (Aythya marila and A. affinis) was the seeds of eelgrass and the principal food of green-winged teal (Anas carolinensis) was the seeds of widgeongrass, (Ruppia maritima). All of these foods were readily available in the study area. The crude protein content of eelgrass blades in winter (14.8%) was found to be adequate for maintenance of Canada geese. Results of previous studies indicate that Canada geese at Port Joli should have been stressed during the study but no overt signs were noted.