Tomlinson Sean, Withers Philip C, Maloney Shane K
School of Animal Biology, Faculty of Science, The University of Western Australia, Crawley 6009, Australia.
School of Animal Biology, Faculty of Science, The University of Western Australia, Crawley 6009, Australia.
Physiol Behav. 2014 Apr 10;128:9-15. doi: 10.1016/j.physbeh.2014.01.020. Epub 2014 Feb 11.
We describe how behavioural responses are an important adjunct to physiological responses for two dunnart marsupials that live in arid environments. Behavioural responses of the stripe-faced dunnart Sminthopsis macroura and the Ooldea dunnart Sminthopsis ooldea differed with acclimation to four ambient temperature (T(a)) regimes, 12 h:12 h of 5-15 °C, 12-22 °C, 18-28 °C and 25-35 °C. Aggression levels were low at regimes 5-15 °C and 12-22 °C, and high at regimes 18-28 °C and 25-35 °C. The proportion of S. macroura huddled in groups increased significantly with decreasing T(a) regime, but there was no aggregation by S. ooldea at low T(a) regimes. The energetic benefit of huddling by S. macroura was highest for pairs of dunnarts (27% saving compared with singles) and only 3% for triplets at T(a)=10 °C. Thermal conductance decreased for pairs but not triplets compared to singles. There were no energetic savings for S. ooldea with increased numbers, and thermal conductance was the same per individual for single, pairs and triplets, reflecting their lack of huddling behaviour. The flexible behavioural (huddling) responses of S. macroura may facilitate their capacity to occupy a broad geographical distribution, unlike S. ooldea, which had inflexible behavioural responses (no huddling) and has a more restricted geographical range. The phylogenetic relationships of the dunnarts suggest that social behaviours may have arisen only once in the most adaptable subgroup of the Sminthopsini.
我们描述了行为反应如何作为两种生活在干旱环境中的袋鼬科有袋动物生理反应的重要辅助因素。条纹脸袋鼬（Sminthopsis macroura）和奥尔德亚袋鼬（Sminthopsis ooldea）在适应四种环境温度（Ta）条件下（12小时光照：12小时黑暗，温度分别为5 - 15°C、12 - 22°C、18 - 28°C和25 - 35°C），行为反应有所不同。在5 - 15°C和12 - 22°C条件下，攻击水平较低；在18 - 28°C和25 - 35°C条件下，攻击水平较高。随着Ta条件降低，条纹脸袋鼬聚集成群的比例显著增加，但在低温Ta条件下，奥尔德亚袋鼬没有聚集行为。在Ta = 10°C时，条纹脸袋鼬成对聚集的能量收益最高（与单独个体相比节省27%），而三只聚集时仅节省3%。与单独个体相比，成对个体的热传导降低，但三只个体没有。奥尔德亚袋鼬数量增加时没有能量节省，单独个体、成对个体和三只个体的个体热传导相同，这反映了它们缺乏聚集行为。与奥尔德亚袋鼬不同，条纹脸袋鼬灵活的行为（聚集）反应可能有助于其占据更广泛的地理分布范围，奥尔德亚袋鼬行为反应不灵活（不聚集），地理分布范围更受限。袋鼬科的系统发育关系表明，社会行为可能仅在袋鼬亚科最具适应性的亚组中出现过一次。
