近年越来越多的实验证据表明，不同动物类群的种群内部个体间存在稳定的行为差异，研究人员把这种现象称为动物个性。目前，有关这种个性特征差异的演化和维持机制，主要认为是受到来自个体自身内部状态介导的正反馈调节。“生境匹配选择”假说提出，个体可以主动选择适合自身表型的生境进行栖息，从而可以使种群内表型多样性得以维持。然而，对于个体所处外部环境的异质性，特别是空间尺度上的环境异质性对种群内行为表型多样共存所发挥的作用还并未得到足够的重视。并且，表型-环境的相关关系同样可以由其他机制过程（如行为的可塑性）造成，使得在野外自然种群中难以对动物个性匹配生境选择这一假说进行直接验证。

因此，本文将以人工繁育饲养的日本鹌鹑（Coturnix japonica）作为实验对象，在受控条件下对生境匹配假说进行验证和探讨。具体将开展有关探索性、勇敢性等个性特征实验，并针对其成长过程中所表现出的相关行为结构（即行为综合征和行为反应范式）开展较为系统的研究，了解笼养条件下动物个体个性特征可能的变异模式。同时，还将基于三种不同取食环境情形（即存在潜在同类、捕食者或二者同时存在）下的取食“斑块”选择实验，来分析个性特征与个体取食决策之间的潜在关系。另外，还将通过不同的社会处理（隔离与非隔离饲养）来探讨社会经历对鹌鹑个体的个性特征及生境选择的影响。主要研究结果如下：

笼养环境下的鹌鹑个体行为特征随时间依然表现出显著的可重复性，表明个体间存在稳定行为差异（即个性）。但其重复性指标并不是很高，均低于0.37（不同动物类群个性特征可重复性的均值水平）。鹌鹑在行为可塑性上也同样具有个体间的稳定差异，但是个性特征与其可塑性之间并未形成耦合关系。另外，也没有发现任何行为综合征的存在。

社会经历差异并没有影响不同组别间行为水平的表达，但却引起了个体水平上行为的差异化。与群养组相比，隔离组鹌鹑一般会表现出更高的行为可重复性。另外，社会经历还被发现影响了个体在镜子实验条件下（模拟存在潜在同类）的取食选择倾向，隔离个体将有更大的倾向选择优质资源且具潜在同类的一侧“斑块”。

个性特征对于取食“斑块”选择偏好的影响因个体面临的环境情形不同而有所不同。在有镜子条件下（潜在同类），社会性更强的个体更偏好食物资源优质且具潜在同类的“斑块”；鹰模型条件下（潜在捕食者），探索性较慢的个体更愿意在食物优质且具潜在捕食风险的一侧停留取食；而当模拟同类与天敌同时存在时，个体的探索性、社会性都会影响其选择，探索性慢、社会性强的个体更倾向选择资源优质且同类与天敌同时存在的一侧。

综上所述，个体间稳定的行为差异依然存在于长期笼养的日本鹌鹑中，这表明较为稳定、均质的笼养环境仍能维持种群内个体间的个性特征差异。但是这种自然选择压力被弱化的笼养条件很可能会对个性相关的行为结构造成潜在影响。本研究还发现个体的个性特征与其取食“斑块”的选择倾向之间存在密切关联，这说明动物个性确实可以对个体的生境选择产生直接的影响。 而且，不同维度的个性特征对于个体选择偏好的影响存在背景依赖的情况。综合分析推测，不同维度上的个性特征很可能是通过介导影响个体对于竞争压力、捕食风险的差异化响应以及取食-安全间的权衡，从而驱动个体基于不同个性特征的生境选择偏好差异。

In recent years, there has been increasingly experimental evidences show consistent inter-individual differences in behavior within a population in many different animal taxa, which has been named as “animal personality” by researchers. The research on the evolution and maintenance of such personality differences has mainly focused on the role of positive feedback regulation mediated by variation of individual internal-state. The “matching habitat choice” hypothesis posits that individuals tend to settle in a habitat that suits their own phenotype, which can can play a role in driving the evolution of phenotypic variation in a population. However, the effect of environmental heterogeneity on such variation in behavior, especially the spatially environmental heterogeneity faced by individuals, has still not been paid enough attention. Furthermore, as the phenotype-environment covariance can also be generated by some other mechanisms, such as behavioral plasticity, it is therefore difficult to directly test the “personality-matching habitat choice” hypothesis directly in the wild.

In this study, we therefore use Japanese quail (Coturnix japonica), artificially raised under captive conditions as our experimental subject, to verity the “matching habitat choice” hypothesis under different controlled experimental conditions. Firstly, we conducted behavioral experiments to assess personality traits, including exploration, boldness, etc. We aim to comprehensively study individual differences in personality traits and personality-related structural characteristics (i.e., behavioral syndromes and personality-plasticity correlations) during the development of quails. It can help us understanding the effects from captive-rearing on different behavioral characteristics. Secondly, we evaluated the potential relationships between personality traits and individuals’ habitat choice through conducting foraging “patch” selection tests under three different contexts (including the existence of potential conspecific, predator or both). We also compared the effects of different social treatments (i.e., quails raised in a group or isolated) on individuals’ personality traits and habitat choice. The main results of this study are shown as follows:

All behavioral traits tested in our quails raised in captivity were repeatable across time, indicating the existence of consistent inter-individual behavioral differences. Nevertheless, the repeatability indices were not very high, which were all lower than 0.37 (a mean value of repeatability of personality traits among different animal taxa). Individuals also showed consistent differences in personality traits changing across time (i.e., plasticity), which however, were not correlated to the personality trait itself. Furthermore, we also did not find any behavioral syndrome structures in the quails.

Different social experiences did not affect behaviors at the inter-group level but at the individual level. Compared with quails that are reared in a group, quails reared in isolation generally have higher behavioral repeatability. And the differences in social experience also influenced the foraging selection tendency of individuals in an environment with a mirror (simulating the context with potential conspecific). We found that quails reared in isolation were more likely to select the “patch” with high-quality resources and potential competition.

The effect of personality traits on foraging selection preference varied among different contexts. Under the context with a mirror (potential conspecific), more social individuals preferred to stay and forage in the “patch” with high-quality resources and potential competition; When an eagle model (potential predator) exists, slow-explorative individuals were more likely to choose the “patch” with high-quality resources and potential predation risk; When the mirror and eagle model coexist, both exploration and sociability would affect individuals’ selection between the two “patches”, i.e. slow-exploration and more social quails tended more to select the high-quality “patch”.

In summary, we confirmed the consistent inter-individual differences in personality traits in Japanese quail after quite a long-term captivity rearing, which implies that a relatively stable and homogeneous captive environment can still maintain personality differences within a population. However, given that strong selection in natural environments generally tends to support stronger behavioral correlations in wild animals, such captive conditions with relaxed natural selection may have negative effects on personality-related structural characteristics, as we found in our quails that there is no behavioral correlations. We also found that personality traits and individuals’ foraging patch choice were significantly related, indicating animal personality might have a direct influence on an individual’s foraging decisions. Furthermore, the roles of different personality traits on such preferences are context-dependent. We suggest that various personality traits may play different roles in mediating individuals’ responses to the competition, predation risk as well as their decisions under the trade-off between foraging and safety, which might in turn drive the evolution of personality-dependent habitat choice.