The Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, UK.
Communication and Social Behaviour Group, Max Planck Institute for Ornithology, 82319, Seewiesen, Germany.
Sci Rep. 2018 Mar 22;8(1):5042. doi: 10.1038/s41598-018-23463-7.
Animals in urban habitats face many novel selection pressures such as increased human population densities and human disturbance. This is predicted to favour bolder and more aggressive individuals together with greater flexibility in behaviour. Previous work has focussed primarily on studying these traits in captive birds and has shown increased aggression and reduced consistency between traits (behavioural syndromes) in birds from urban populations. However, personality (consistency within a behavioural trait) has not been well studied in the wild. Here we tested whether urban free-living male great tits show greater territorial aggression than rural counterparts. We also tested predictions that both behavioural syndromes and personality would show lower consistency in urban populations. We found that urban populations were more aggressive than rural populations and urban birds appeared to show lower levels of individual behavioural repeatability (personality) as predicted. However, we found no effect of urbanisation on behavioural syndromes (correlations between multiple behavioural traits). Our results indicate that urban environments may favour individuals which exhibit increased territorial aggression and greater within-trait flexibility which may be essential to success in holding urban territories. Determining how urban environments impact key fitness traits will be important in predicting how animals cope with ongoing urbanisation.
城市栖息地中的动物面临着许多新的选择压力，例如人口密度增加和人类干扰。这预计会有利于更大胆、更具攻击性的个体，以及行为的更大灵活性。以前的工作主要集中在研究圈养鸟类的这些特征上，并表明城市鸟类的攻击性增加，行为特征（行为综合征）之间的一致性降低。然而，个性（行为特征内的一致性）在野外并没有得到很好的研究。在这里，我们测试了自由生活在城市中的雄性大山雀是否比农村的同类表现出更强的领地攻击性。我们还测试了这样的预测，即行为综合征和个性在城市种群中表现出较低的一致性。我们发现，城市种群比农村种群更具攻击性，而且城市鸟类似乎表现出较低的个体行为可重复性（个性），这与预测结果一致。然而，我们没有发现城市化对行为综合征（多个行为特征之间的相关性）有影响。我们的研究结果表明，城市环境可能有利于表现出更强领地攻击性和更大行为灵活性的个体，这对于在城市地区拥有领地可能是至关重要的。确定城市环境如何影响关键的适应度特征，对于预测动物如何应对持续的城市化将是重要的。
