Using population viability analysis to guide research and conservation actions for Australia's threatened malleefowl Leipoa ocellata

Abstract

AbstractMalleefowl Leipoa ocellata populations across Australia are declining and the range of the species is contracting. Despite a century of research much uncertainty remains about which factors are driving this decline. Consequently, it is also unclear which conservation actions will reduce the species’ extinction risk. In particular, we lack a quantitative understanding of malleefowl population dynamics. Here we use estimates derived from the literature to provide the first parametrization of a population viability analysis (PVA) for malleefowl. This model creates a quantitative framework for synthesizing existing information and comparing potential management strategies, and will help guide research activities by identifying critical aspects of the malleefowl’s life history. We model population dynamics as stochastic events that depend on individual characteristics, weather conditions and local management actions. Our PVA indicates that an isolated population of 32 adult birds would almost certainly decline to extinction over a 20-year period. Translocating and releasing captive-bred juveniles slows this rate of decline and intensively baiting for foxes can reverse it. Adult mortality rates have the greatest influence on population viability, and land managers should therefore prioritize conservation actions that target adult survivorship over actions that benefit earlier life stages. Quantitative research on the malleefowl should focus on the demographics of the adult life stage, their dispersal and the impacts of fire and grazing. Our analysis highlights the role of PVA models in assessing the cost-effectiveness of alternative management actions, and framing future research priorities for threatened species.