Cognitive traits are predicted to be under intense selection in animals moving into new environments and may determine the success, or otherwise, of dispersal and invasions. In particular, spatial information related to resource distribution is an important determinant of neural development. Spatial information is predicted to vary for invasive species encountering novel environments. However, few studies have tested how cognition or neural development varies intraspecifically within an invasive species. In Australia, the non-native common starling Sturnus vulgaris inhabits a range of habitats that vary in seasonal resource availability and distribution. We aimed to identify variations in the brain mass and hippocampus volume of starlings in Australia related to environmental variation across two substantially different habitat types. Specifically, we predicted variation in brain mass and hippocampal volume in relation to environmental conditions, latitude, and climatic variables. To test this, brain mass and volumes of the hippocampus and two control brain regions (telencephalon and tractus septomesencephalicus) were quantified from starling brains gathered from across the species' range in south eastern Australia. When comparing across an environmental gradient, there was a significant interaction between sex and environment for overall brain mass, with greater sexual dimorphism in brain mass in inland populations compared to those at the coast. There was no significant difference in hippocampal volume in relation to environmental measures (hippocampus volume, n = 17) for either sex. While these data provide no evidence for intraspecific environmental drivers for changes in hippocampus volume in European starlings in Australia, they do suggest that environmental factors contribute to sex differences in brain mass. This study identifies associations between the brain volume of a non-native species and the environment; further work in this area is required to elucidate the mechanisms driving this relationship.

中文翻译：

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环境对非原生八哥类turn的神经形态的影响。

据预测，在进入新环境的动物中，认知特征处于强烈选择之下，并且可能决定扩散和入侵的成功与否。特别是，与资源分配有关的空间信息是神经发育的重要决定因素。对于遇到新环境的入侵物种，空间信息预计会有所不同。但是，很少有研究测试在入侵物种内，认知或神经发育如何在种内发生变化。在澳大利亚，非本地常见的八哥类寻常八哥生活在各种生境中，这些生境的季节性资源可利用性和分布各不相同。我们的目的是确定澳大利亚star鸟的大脑质量和海马体数量的变化与两种基本不同的生境类型的环境变化有关。特别，我们预测了大脑质量和海马体积与环境条件，纬度和气候变量相关的变化。为了测试这一点，从澳大利亚东南部跨物种范围收集的八哥大脑中，对海马和两个对照大脑区域（端脑和小管隔脑）的大脑质量和体积进行了定量。在整个环境梯度之间进行比较时，性别与环境之间的总体脑质量之间存在显着的相互作用，与沿海地区相比，内陆人口的脑质量具有更大的性二态性。两种性别的海马体积相对于环境测量（海马体积，n = 17）都没有显着差异。尽管这些数据没有提供证据证明种内环境驱动因素导致澳大利亚欧洲八哥的海马体体积发生变化，但它们确实表明环境因素导致了大脑质量的性别差异。这项研究确定了非本地物种的大脑容量与环境之间的关联。需要在这一领域做进一步的工作来阐明驱动这种关系的机制。