Hot, unpredictable weather interacts with land use to restrict the distribution of the Yellow-tailed Black-Cockatoo

Abstract

Conserving nomadic species is challenging due to the difficulty in monitoring their characteristically transient populations, and thereby detecting range-wide declines. An example is the Yellow-tailed Black-Cockatoo (YTBC; Zanda funerea), which disperses widely in search of food and is regularly–but sporadically–observed across eastern Australia. Under climate warming, a general southward shift in species distributions is expected in the southern hemisphere, with the extreme southern margins being truncated by an ocean barrier. Given these constraints, we ask whether sufficient refugia will exist for the YTBC in the future, by: (i) modelling habitat relationships within the current geographic range of the YTBC based on weather, climate, vegetation, and land use, and (ii) using this framework, coupled with climate-model projections, to forecast 21st century impacts. Intensive land use and high variability in temperature and rainfall seem to most limit YTBC occurrence. In contrast, areas with a cooler, stable climate and a network of old-growth forests, such as those in parts of south-eastern Australia and Tasmania, are most suitable for the species. As Australia becomes progressively hotter under climate change, the preferred bioclimatic envelope of the YTBC is forecast to contract poleward (as a general pattern) and to fragment within the existing range. However, despite an extensive loss of climatically suitable regions, the YTBC might find stable refugia at the southern margins of its geographic range, although continued loss of old-growth forests undermines their nesting potential. Therefore, beyond habitat conservation, creating nesting opportunities within plantation forests would likely be an effective conservation strategy to preserve habitat quality in climate refugia.