Survival of female American Woodcock breeding in Maine

Abstract

During 1986-1989, 89 female American woodcock (Scolopax minor) included in this study were radio-marked and survival estimated for the period 1 Aprii-15 June. Eleven woodcock died: five (45%) were killed by mammals, two (18%) by unknown predators, and one (9%) by a raptor; two (18%) died from entanglement in the transmitter harness; and 1 (9%) collided with a vehicle. Survival varied among years from 0.700 (1986) to 0.900 (1989) with a 4-year mean (95% CI) of 0.826. Survival did not differ between age classes (P = 0.900), or among years (P > 0.14), except for higher (P = 0.025) survival (0.875) in 1987 than in 1988 (0.735). A composite survival estimate--based on telemetry studies for the breeding, post-breeding, and winter periods-- was 0.363 for immatures and 0.474 for adults. Mean weights were not different between second year and after second year age classes (P = 0.167), but weight was related to woodcock capture date (P = 0.001). Survival for female woodcock was not related to mean snow depth or to mean, minimum temperature in winter or spring. Habitat use was different between females that died and those that lived, but sample size was small.