Using the double-observer method to estimate detection probability of two cavity-nesting seabirds in Antarctica: The snow petrel (Pagodroma nivea) and the Wilson's storm petrel (Oceanites oceanicus)

Abstract

When estimating the size of seabird populations, count data may be biased due to various factors such as detection probability. Failing to account for detection probability in surveys may lead to an underestimate of population size and may compromise the ability to monitor trends if detection probability varies among surveys. Here, we use the double-observer method to estimate detection probability of cavity-nesting snow petrels (Pagodroma nivea) and Wilson's storm petrels (Oceanites oceanicus) in East Antarctica. Estimates of single-visit detection probability of nesting/roosting adult snow petrels during the incubation stage of the breeding cycle ranged from 0.86 (SE = 0.04) to 0.87 (SE = ..