Time Budget of Behavior among Lesser Scaups on Delta Marsh

Time budgets of diurnal behaviors were determined for lesser scaups (Aythya affinis) visiting the Delta Marsh, Manitoba, during the period 3-26 May 1971. Of 3,932 birds observed, 68 percent were males of which 53 percent were unmated. All but 3 females appeared to be mated. Resting and foraging were major components of the total time budget. The proportion of foraging females generally exceeded the proportion of foraging males, because individual females generally devoted more time to foraging and foraged more intensively than their mates. Mated males spent relatively more time swimming; unmated males spent most of their time resting. Foraging behavior consisted almost exclusively of diving. Females averaged 195 foraging dives per hour and foraged for one out of every three hours during the period 0600-2200 hours (local standard time). Courtship, and other epigamic behavior, constituted a minor percentage of the total behavioral activity.