SURVIVAL OF FEMALE NORTHERN PINTAILS WINTERING IN SOUTHWESTERN LOUISIANA

The North American breeding population of northern pintails (Anas acut a) has reached previously unprecedented low numbers 4 times since 1983 . Because pintails show high fidelity to wintering areas, regional sur vival estimates and identification of factors influencing survival are needed to guide management of wintering pintails. We used radioteleme try to estimate survival rates of female pintails wintering in southwe stern Louisiana. We tested for variation in survival and hunting morta lity rates in relation to age (immature or adult), winter (1990-91, 19 91-92, 1992-93), time period (prehunting season, first hunting season, time between split hunting seasons, second hunting season, posthuntin g season), body condition (body mass when released, adjusted for body size), and region (southwestern Louisiana or elsewhere on the Texas-Lo uisiana Gulf Coast or Mississippi Alluvial Valley). Within southwester n Louisiana, the 147-day (5 Oct-28 Feb) survival rate of adults (0.714 +/- 0.045; (x) over bar +/- SE) was greater (P = 0.02) than that of i mmatures (0.550 +/- 0.068), primarily because immatures had higher hun ting mortality. Female survival was lower (Ps < 0.01) during hunting t han during nonhunting seasons but did not differ between first and sec ond hunting seasons (P = 0.58) or among nonhunting seasons (Ps > 0.25) . Survival did not differ in relation to winter or condition (Ps > 0.1 2). Hunting mortality did not differ (Ps > 0.13) in relation to winter , condition, or region. but hunting mortality of immatures (0.287 +/- 0.046) was greater (P < 0.001) than that of adults (0.130 +/- 0.025). Despite conservative hunting regulations (30-day seasons and 1 pintail daily), hunting mortality rates of pintails in southwestern Louisiana were high. Pintails in southwestern Louisiana rely on a small number of key refuges for protection but feed almost exclusively in privately owned agricultural fields. If increased winter survival of female pin tails in southwestern Louisiana is desired, we recommend that managers increase food availability on refuges.