Diurnal activity budgets and habitat functions of Northern Pintail Anas acuta wintering in Sinaloa, Mexico

Abstract

We determined the activity budgets and habitat use patterns of Northern Pintail wintering in the Ensenada del Pabelln Coastal System in Sinaloa, Mexico, over the winters of 1989-90, 1990-91 and 1991-92. Radio-marked females (n = 47-59/year) were used to lead observers to Pintail flocks, where time budget data were collected. Dominant daytime activities were resting (47%), feeding (20%), preening (17%) and locomoting (13%). Annual variation was high and depended on the availability and functional use of four habitat types. Natural fresh-brackish marshes were used for resting (34-58%), feeding (6-39%), and social activity (0.4-6%). Ephemeral ponds also were used for feeding 7-43%) and social activity (0.3-4%) during some wintering periods, but they generally functioned as resting areas (31-71%). Mangrove mudflats were used for resting (51-79%), whereas reservoirs were used for resting (44-54%) and social activity (1-5%), particularly during midwinter. Management recommendations include enhancing rice availability, but also improving quality of natural marshes via control of Cattail.