Impacts of climate change and variability on penguins

Abstract

Climate change and climate variability have been shown to affect a broad range of species worldwide. As seabirds are likely to be affected by changing climate while breeding on-land and foraging at-sea, their population status and ecological changes are monitored as indicators of ecosystem change. This paper reviews the ecological processes and population consequences of climate impacts on penguins. The review shows that climate change and climate variability are important factors driving the changes in the population size and breeding success of various penguin species (up to 13 of 18 extant species) via changes in their breeding and foraging environments. However, these factors affect penguins in a complex way. For example, the effects of a warming climate can vary from negative to positive in different parts of the distribution range of a single species, or in different life-history parameters within a single population (e.g., breeding success vs. adult survival rates). Some simulation studies have produced future population projections for Antarctic and subantarctic penguins based on multiple climate change scenarios, emphasizing the importance of climate mitigation. The results of these simulations should still be interpreted with caution, while appreciating the uncertainties associated with climate projections and penguin responses to future climate. More research on penguin foraging ecology is needed, especially during data-poor non-breeding or juvenile periods, to elucidate fully the processes of climate impacts on penguins. Finally, mitigating existing human impacts is essential to safeguard penguin species, and will help penguin populations become more resilient to existing and future climate impacts.