Urbanisation changes the structure of natural habitats and alters trophic interactions, pressuring urban species to adjust and adapt. Unlike behavioural shifts that tend to be more flexible, morphological characteristics in vertebrates are less plastic and changes may come at a greater cost. We explored the hypothesis that morphological characteristics in a tropical agamid lizard Psammophilus dorsalis are not only selected to suit altered habitat conditions in urbanised areas but reflect predation risk in urban habitats. In addition, we explored differences in tail loss in both sexes from urban and rural habitats. First, we find that predation risk did not differ between urban and rural habitats, but differed between sexes. Conspicuous courtship-coloured male lizards were more likely to be attacked compared to cryptically-coloured female lizards. Next, we find that P. dorsalis differed in key morphological characteristics, with greater urban-rural differences in males than females. Urban lizards had shorter proximal limb elements, longer 4th digits and greater body mass than rural lizards; and among males, urban lizards had significantly larger head sizes and longer distal limb elements than rural lizards. Finally, we find that the rates of tail loss differed between habitats and sexes, with urban male lizards having greater rates of tail loss than rural males and all females. Inter-sexual difference in tail loss was consistent with the difference in predation risk between sexes, but tail loss differences between urban and rural habitats could not be explained by predation risk. In sum, we find that adaptations to novel urban environments are not exclusively driven by a single promoter (e.g. predation risk) but are influenced by multiple selection pressures with associated fitness costs, such as tail loss.

城市化改变了自然栖息地的结构并改变了营养相互作用，迫使城市物种进行调整和适应。与趋向于更灵活的行为转变不同，脊椎动物的形态特征具有较少的可塑性，并且变化的代价可能更大。我们探索了一种假设，即热带agamid蜥蜴Psammophilus dorsalis的形态特征选择它们不仅适合于城市化地区生境的变化，还反映了城市生境中的捕食风险。此外，我们探索了来自城市和农村栖息地的男女尾巴损失的差异。首先，我们发现在城市和乡村栖息地之间的捕食风险没有差异，但是在性别之间却存在差异。与色泽暗淡的雌性蜥蜴相比，显眼的求偶色雄性蜥蜴更容易受到攻击。接下来，我们发现P. dorsalis关键形态特征上的差异，男性与女性之间的城乡差异更大。与农村蜥蜴相比，城市蜥蜴的近肢肢体更短，四位数更长，体重更大。在男性中，城市蜥蜴的头顶大小和远端肢体元素比农村蜥蜴大得多。最后，我们发现生境和性别之间的尾巴损失率不同，城市雄性蜥蜴的尾巴损失率高于农村雄性和所有雌性。两性之间的性行为差异与性别之间的捕食风险差异一致，但城乡生境之间的尾部损失差异不能用捕食风险来解释。总而言之，我们发现，对新型城市环境的适应并非仅由单个推动者驱动（例如