The climate crisis is raising the temperature around the world, but in South Africa, the rise has been particularly worrisome. Wild animals that depend on sensitive ecosystems that are already dry, and so scarce food and water limit their ability to cope with the increasing heat, are at serious risk. Scientists studied the behavior of three different species of antelope with overlapping ranges in Namibia to try to understand how animals of different sizes and behaviors adapt to heat.
said Paul Perry of the University of Potsdam, lead author of the study Frontiers in ecology and evolution. “We need to consider the possibility that additional human impacts such as habitat fragmentation may increase the impact of warming.”
Heat stress treatment
Animals can respond to high heat in many different ways, including genetic change, migration, and behavior change, but the most flexible response is to change their behaviour. Animals may move to cooler areas within their territory, change their position, change their activity times or the amount of activity they do, pant or reduce their energy expenditure. All of these methods of coping with heat stress impose physical costs and have limitations, but we cannot understand the trade-offs without first understanding how animals use them.
The team studied three species of antelope: a small springbok, a medium-sized kudu, and a large eland. Springbok prefer open habitats and are highly mobile, while kudu prefer woodlands and travel less. Eland are also relatively mobile, occurring in a wide range of habits, and like Springbok are largely independent of water provided there is sufficient moisture in their food.
The scientists fitted the adult animals with collars containing accelerometers that measured their movements during the hottest time of the year between 2019 and 2021. They cross-referenced this data with measurements recorded by a local weather station and maps that track temperatures across different species. scopes.
Springbok hit hardest
Hotter temperatures affected Springbok activity more. Increasing heat has led to a decrease in activity, as they move less during the day and do not compensate for more nocturnal activity. Eland have shifted their activity from day to night, but have been less affected overall, perhaps because they don’t eat in open, exposed areas as often as springbok do. Kudu’s activity has changed very little: they usually prefer shade and are less mobile than any of the other species. Eland and kudu are also larger, and besides being less vulnerable to predation risk because they are more difficult to hunt, they may be able to absorb a larger rise in heat before being severely affected by heat stress.
“While we have shown how antelopes differ in their response to extreme heat, it will be insightful to also know how they change their behaviour,” Perry said. “We intend to use machine learning models to classify behavior, such as feeding, resting, and movement, based on accelerometer data mapped to the behavior through direct observation.”
Scientists also hypothesized that the thermal response of other animals could be similarly affected by body size and habitat preference factors, but more research would be needed to determine this. Because non-lethal heat stress can affect the reproductive health and fitness of a group of animals, the authors warn that increased heat stress can lead to changes in the ecosystem, with severe consequences for the local area.
said Dr. Nils Blom of the University of Potsdam, senior author of the study. Therefore, deepening our understanding of arid savannah ecosystems is of the utmost importance.
more information:
Keeping cool on hot days: African antelope activity responses to extreme heat. Frontiers in ecology and evolution (2023). DOI: 10.3389/fevo.2023.1172303
the quote: How antelopes threatened by the climate crisis have responded to rising temperatures (2023, June 15) June 15, 2023 from https://phys.org/news/2023-06-antelopes-threat-climate-crisis-temperatures.html
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