ESR SPECIAL PrePrint (2008) - Abstract

ABSTRACT: Understanding the demography of the Critically Endangered waved albatross Phoebastria irrorata is crucial for effective policy responses to recent threats, most notably fishery mortality. Using current vital rates data and a stochastic matrix model, we confirm the conclusion of Awkerman et al. (2006) that the population growth rate (λ) was less than 1 in recent years, indicating a shrinking population. Earlier comparisons of recent population size suggested that the breeding population shrunk between 1994 and 2001, but these were based on only 2 counts. A new count in 2007 indicated continued reduction in breeding population size, and the magnitude of the recent reduction was consistent with that projected by our model. New information suggests that plastic ingestion appears to pose a minor threat, if any, to this species, in contrast to the serious problems that it causes in some other albatrosses. Reduction of adult mortality in the coastal fishery appears to be the most effective means to stabilize this threatened species.

KEY WORDS: Annual adult survival · Fecundity · Galápagos · Stochastic matrix model · Plastic pollution · Waved albatross