Effects of Food Abundance and Environmental Parameters on Foraging Behavior of Gadwalls and American Coots in Winter

摘要: Diurnal behaviors of wintering gadwalls (Anas strepera) and American coots (Fulica americana) were studied at Guntersville Reservoir, Alabama. Feeding accounted for a substantial amount time spent by (>50%) (>62%). rate (pecks per minute) female was higher than that males, foraging speed (metres unpaired paired birds. For both coots, increased feeding decreased over time. Stepwise multiple regression used to test the effects food abundance, day length, ambient temperature, mean daily wind on speed. Foraging with declining abundance coots. Additionally, length small but significant variation in Moving faster while probably allowed maintain adequate intake nutritious items from resource. Variation not explained or environmental variables. decreasing temperature. As declined, reduced density suitable resulted fewer surface pecks more time-consuming dives. The lower temperatures thermoregulatory costs. Unlike typically do dive, adjusted stealing diving Because exploited bringing January February, gadwall during this somewhat uncoupled surface. Although diurnal is limiting some waterfowl species, results present study indicate Alabama predominantly response changes abundance.