18.01.2021: The world is in the midst of climate change. But how exactly does this affect the animal world in its current areas of distribution? To cope with environmental fluctuations, including climate change and global warming, animal species employ various adaptive strategies, which include the use of hypometabolic states, e.g. torpor and hibernation, and the modulation of energy management including its effects when animals grow into adults. This is discussed in a current special edition of the leading physiological, ecological, and evolutionary science journals Frontiers in Physiology and Frontiers in Ecology and Evolution, which includes 15 publications. In the editorial of the special edition, written by editors Sylvain Giroud from the Research Institute of Wildlife Ecology (Vetmeduni), Andreas Nord from Lund University (Sweden), Kenneth Storey from Carleton University (Canada), and Julia Nowack from Liverpool John Moores University (UK), what becomes clear is that despite use of plastic physiological and behavioural responses, climate change is still likely to impact animal function.
Animals are well adapted to their environment enabling them to cope well with significant seasonal fluctuations in one or more environmental parameter. Recently, however, organisms around the world have also had to deal with accelerated climate change, which is characterized both by a slow rise in average temperature and an increased frequency of extreme weather events. To predict how this will affect wildlife, it is important to understand the limits to the ecological and physiological strategies that animals use to deal with fluctuating weather in their current ranges.
Clear findings from numerous fields of science
The research topic, edited by Giroud and his international co-authors, provides a comprehensive overview of recent advances in mechanistic and ecological-evolutionary aspects of how animals deal with fluctuating and changing environments in the form of primary research articles, perspective pieces, and reviews. The studies ranged research in molecular and cellular biology through organismal and population level responses in mammals, birds and ectothermic (“cold-blooded”) animals.
Animal adaptive responses to climate change and changing environmental conditions
According to Sylvain Giroud, three main aspects must be considered when thinking about how animals react to environmental fluctuations: "The effects of climate change can be read particularly well using three responses. On the one hand, there is the seasonal use and the development of hypometabolism and heterothermy, i.e. what we know as hibernation and torpor. Another factor are metabolic responses, i.e. changes in energy metabolism and water economy in response to dry, energy-limited, or hypoxic environments. And the third adaptive response is the temperature sensitivity of animals during their development and the resulting lifelong effects".
According to the latest study results, the use of torpor -which significantly reduces the metabolic rate along with a drop of body temperature- by endothermic animals (i.e. those usually keeping their own body temperature constant), is not as seasonal as generally assumed. The flexible use of this ability to go into torpor, or enter a hypometabolic state, is believed to be beneficial when species must be resilient to climate change.
The research topic emphasises that global warming affects species differently: While zebra finches, a desert bird, are well prepared for heat waves as long as there is enough water and are rather challenged by cold weather, summer droughts lead to reduced foraging and increased mortality in South African aardvarks. In addition, the research topic also focussed on the phenomenon that climate change and extreme weather events can also have pronounced effects during animals´ development, allowing animals to adapt to the climatic conditions they were exposed to during early life."We hope that this research topic provides a solid platform for the multidisciplinary research efforts needed to understand and draw the relevant conclusions from the challenges and capacities for adaptation to climate change in the 21st century and beyond," said Giroud.
The editorial "Coping With Environmental Fluctuations: Ecological and Evolutionary Perspectives" by Sylvain Giroud, Andreas Nord, Kenneth B. Storey and Julia Nowack was published in Frontiers in Physiology.
The Research Topic has been complied in an eBook, which includes the editorial and all contributions.