Department of Biosciences, Swansea University, Swansea SA2 8PP, UK.
Banded Mongoose Research Project, Queen Elizabeth National Park, Kasese District, Uganda.
Biol Lett. 2023 Nov;19(11):20230328. doi: 10.1098/rsbl.2023.0328. Epub 2023 Nov 22.
Human-induced climate change is leading to temperature rises, along with increases in the frequency and intensity of heatwaves. Many animals respond to high temperatures through behavioural thermoregulation, for example by resting in the shade, but this may impose opportunity costs by reducing foraging time (therefore energy supply), and so may be most effective when food is abundant. However, the heat dissipation limit (HDL) theory proposes that even when energy supply is plentiful, high temperatures can still have negative effects. This is because dissipating excess heat becomes harder, which limits processes that generate heat such as lactation. We tested predictions from HDL on a wild, equatorial population of banded mongooses (). In support of the HDL theory, higher ambient temperatures led to lighter pups, and increasing food availability made little difference to pup weight under hotter conditions. This suggests that direct physiological constraints rather than opportunity costs of behavioural thermoregulation explain the negative impact of high temperatures on pup growth. Our results indicate that climate change may be particularly important for equatorial species, which often experience high temperatures year-round so cannot time reproduction to coincide with cooler conditions.
人为引起的气候变化导致气温上升，同时热浪的频率和强度也在增加。许多动物通过行为体温调节来应对高温，例如在阴凉处休息，但这可能会通过减少觅食时间（因此减少能量供应）而产生机会成本，因此在食物充足时可能最有效。然而，热耗散极限（HDL）理论提出，即使能量供应充足，高温仍然会产生负面影响。这是因为散发多余的热量变得更加困难，这限制了产生热量的过程，如泌乳。我们在一个野生的、赤道地区的带纹獴（）种群中测试了 HDL 的预测。支持 HDL 理论，较高的环境温度导致幼崽较轻，而在较热的条件下，增加食物供应对幼崽体重的影响很小。这表明，直接的生理限制而不是行为体温调节的机会成本解释了高温对幼崽生长的负面影响。我们的研究结果表明，气候变化可能对赤道物种尤其重要，这些物种通常全年都经历高温，因此无法将繁殖时间与较凉爽的条件相吻合。
