Bandicoots and bilbies (Order Peramelemorphia) occupy a broad range of habitats across Australia and New Guinea, from open, arid deserts to dense forests. This once diverse group has been particularly vulnerable to habitat loss and introduced eutherian predators, and numerous species extinctions and range retractions have occurred. Understanding reasons for this loss requires greater understanding of their biology. Morphology of the pinnae and tympanic bullae varies markedly among species. As hearing is important for both predator avoidance and prey location, the variability in ear morphology could reflect specialization and adaptation to specific environments, and therefore be of conservation relevance. We measured 798 museum specimens representing 29 species of Peramelemorphia. Controlling for phylogenetic relatedness and head length, pinna surface area was weakly negatively correlated with average precipitation (rainfall being our surrogate measure of vegetation productivity/complexity), and there were no environmental correlates with effective diameter (pinna width). Controlling for phylogenetic relatedness and skull length, tympanic bulla volume was negatively correlated with precipitation. Species that inhabited drier habitats, which would be open and allow sound to carry further with less obstruction, had relatively larger pinnae and tympanic bullae. In contrast, species from higher rainfall habitats, where sounds would be attenuated and diffused by dense vegetation, had the smallest pinnae and bullae, suggesting that low-frequency hearing is not as important in these habitats. Associations with temperature did not reach statistical significance. These findings highlight linkages between hearing traits and habitat that can inform conservation and management strategies for threatened species.

中文翻译：

---

保持警惕：袋狸和袋鼠鼓膜大泡和耳廓的大小关系（有袋动物：Peramelemorphia）

Bandicoots 和 bilbies (Order Peramelemorphia) 在澳大利亚和新几内亚占据了广泛的栖息地，从开阔的干旱沙漠到茂密的森林。这个曾经多样化的群体特别容易受到栖息地丧失和引入eutherian食肉动物的影响，并且发生了许多物种灭绝和范围收缩。了解这种损失的原因需要更多地了解它们的生物学。耳廓和鼓膜大疱的形态在物种之间有显着差异。由于听力对于避免捕食者和猎物定位都很重要，耳朵形态的变异性可以反映专业化和对特定环境的适应，因此具有保护相关性。我们测量了代表 29 种 Peramelemorphia 的 798 个博物馆标本。控制系统发育相关性和头长，耳廓表面积与平均降水量呈弱负相关（降雨量是我们衡量植被生产力/复杂性的替代指标），并且与有效直径（耳廓宽度）没有环境相关性。控制系统发育相关性和颅骨长度，鼓泡体积与降水呈负相关。栖息在干燥栖息地的物种，这些栖息地是开放的，可以让声音以更少的障碍传播到更远的地方，它们的耳廓和鼓泡相对较大。相比之下，来自高降雨量栖息地的物种（声音会被茂密的植被减弱和扩散）具有最小的耳廓和大疱，这表明低频听力在这些栖息地并不那么重要。与温度的关联没有达到统计学意义。