Animal responses to natural disturbance and climate extremes: a review

Natural disturbances, such as droughts, fires or hurricanes, are key drivers of ecological heterogeneity and ecosystem function. The frequency and severity of these episodes is unequivocally expected to increase in the coming decades, through the concerted action of climate change and anthropogenic pressures. This will impose severe challenges for many biota through exposure to rapidly changing conditions never experienced in the preceding millennia. Thus, it is urgently needed to gain a thorough understanding of animal responses and adaptations to disturbances in order to better estimate potential future impacts. Here, we review such adjustments and find that animals may respond to disturbances through changes in: (1) behaviour, such as altered mobility, emigration, resource-switching, refuge use, suspended animation, or biotic interactions; (2) life history traits, such as survival, aging, longevity, recruitment, reproductive restraint, breeding output, phenology and bet-hedging tactics; (3) morphology, such as rapid evolution through size-dependent mortality or facultative metamorphosis; (4) physiology, such as altered body condition, pathogen prevalence and transmission, or adrenocortical modulation of stress responses to emergency conditions; (5) genetic structure, such as changes in frequency of polymorphic variants or diversity-modulation through mortality bottlenecks. Individual-level responses scale up to population and community responses, such as altered density, population dynamics, distribution, local extinction and colonization, or assemblage structure and diversity. Overall, disturbances have pervasive effects on individuals, populations and communities of vertebrates and invertebrates of all realms, biomes, continents and ecosystems. Their rapidly increasing incidence and severity will bring unique study opportunities for researchers and novel, unpredictable challenges for managers, while demanding tougher choices and more proactive crisis-preparation for conservationists, as well as mentality changes for all. Under all conditions, disturbances may soon become the defining signatures of most ecosystems and the dynamic leitmotif of modern ecology.