Identifying factors affecting captive breeding success in a critically endangered species

ABSTRACT Captive breeding programs are an increasingly important tool for species’ conservation efforts, but not all species reproduce well in captivity. Identifying factors that affect the reproductive success of captive populations is crucial to improving the performance and management of conservation-breeding programs, both by providing individuals for release and informing decision making. We examined breeding records collected from the long-running conservation-breeding program for the critically endangered Orange-bellied Parrot Neophema chrysogaster over an 11-year period. We examined egg hatching rate, nestling survival rate, and offspring sex ratio in response to a wide range of variables related to characteristics of individual birds, breeding events, and the captive environment. The hatch rate of eggs was higher in first clutches compared to second clutches and was lower than the wild population. The survival rate of nestlings through to fledging was variable between years but became higher and more consistent over the last five years of the study period. Variation in brood sex ratio was not related to any of the potential explanatory variables that we examined. This is one of the first studies to examine reproductive data in a long-running conservation-breeding program and shows that many common metrics do not explain reproductive variation. Our approach provides a framework for managers to investigate factors affecting reproductive success in conservation breeding programs more broadly.