An Approach to Distinguish between Plasticity and Non-random Distributions of Behavioral Types Along Urban Gradients in a Wild Passerine Bird
An Approach to Distinguish between Plasticity and Non-random Distributions of Behavioral Types Along Urban Gradients in a Wild Passerine Bird
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DOI：
10.3389/fevo.2017.00092
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发表时间：
2017
影响因子：
3
通讯作者：
P. Sprau;N. Dingemanse
中科院分区：
文献类型：
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作者：
P. Sprau;N. Dingemanse
在物种多样性和生活史演化的背景下，城市化的影响已经得到了广泛的研究。相比之下，行为适应仍然知之甚少，因为实证研究很少调查两种关键机制的相对重要性：行为类型的可塑性反应与非随机分布。我们在这里提出了一种方法，能够同时估计这些不同机制的各自作用。我们调查了为什么危险行为经常与城市化联系在一起，使用城市大山雀巢箱种群(Parus Main)作为研究系统。我们同时反复量化了个人行为(攻击性和飞行启动距离)以及表征城市化水平的环境因素(行人、汽车和骑自行车的人数)。这使我们能够从统计上区分塑料反应和行为类型的非随机分布模式。数据分析表明，个人并没有根据城市化水平对自己的行为进行可塑性调整。相反，行为类型是非随机分布的：大胆的鸟更多地出现在汽车多、行人少的地区，而害羞的人主要出现在汽车少、行人多的地区。这些新的发现暗示了行为类型在城市环境进化生态中的重要作用，并呼吁在城市生态研究中充分整合个体之间和个体内部的差异。
The impact of urbanization has been widely studied in the context of species diversity and life history evolution. Behavioural adaptation, by contrast, remains poorly understood because empirical studies rarely investigate the relative importance of two key mechanisms: plastic responses vs. non-random distributions of behavioural types. We propose here an approach that enables the simultaneous estimation of the respective roles of these distinct mechanisms. We investigated why risky behaviours are often associated with urbanisation, using an urban nest box population of great tits (Parus major) as a study system. We simultaneously and repeatedly quantified individual behaviour (aggression and flight initiation distance) as well as environmental factors characterizing level of urbanisation (numbers of pedestrians, cars and cyclists). This enabled us to statistically distinguish plastic responses from patterns of non-random distributions of behavioural types. Data analyses revealed that individuals did not plastically adjust their behaviour to the level of urbanization. Behavioural types were instead non-randomly distributed: bold birds occurred more frequently in areas with more cars and fewer pedestrians while shy individuals were predominantly found in areas with fewer cars and more pedestrians. These novel findings imply a major role for behavioural types in the evolutionary ecology of urban environments and call for the full integration of among- and within-individual variation in urban ecological studies.