EVENING FLIGHTS OF FEMALE NORTHERN PINTAILS FROM A MAJOR ROOST SITE

We monitored evening flights of female Northern Pintails (Anas acuta) from Lacassine National Wildlife Refuge (NWR) in southwestern Louisian a during winters of 1991-1992 and 1992-1993. We analyzed the influence of female age, winter, and date within wintering period on three flig ht parameters: distance, duration, and departure time. Flight distance and duration increased with date within wintering period, and age dif ferences in flight distance and duration were not consistent between w inters. Females departed 12 min later, on average, on clear, moonlit e venings than on overcast, moonless evenings, and 4 min later when wind s were light rather than heavy. After controlling for variation due to environmental conditions, immature females departed Lacassine NWR 1.3 min earlier, on average, than did adults. Flight parameters of female s did not differ between hunting and non-hunting time periods. Estimat ed daily transit costs ranged from 27-54% of basal metabolic rate, 7-1 9% of daily energy expenditure, and 8-20% of daily dietary intake of r ice (Oryza sativa). Our findings that flight distance and duration inc reased with date within wintering period were consistent with predicti ons of refuging theory, but alternative hypotheses also could explain these results. Evening flights of Northern Pintails roosting on Lacass ine NWR were greater in distance and duration than those reported for most other species of wintering waterfowl. We recommend that proximity of refuges to feeding sites be considered in conservation and managem ent plans for wintering Northern Pintails and other refuging waterfowl .