Dawson Pell Francesca S E, Senar Juan Carlos, Franks Daniel W, Hatchwell Ben J
Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.
Museu de Ciències Naturals de Barcelona, Barcelona, Spain.
Mol Ecol. 2021 Mar;30(6):1531-1544. doi: 10.1111/mec.15818. Epub 2021 Feb 9.
The genetic structure of animal populations has considerable behavioural, ecological and evolutionary implications and may arise from various demographic traits. Here, we use observational field data and molecular genetics to determine the genetic structure of an invasive population of monk parakeets, Myiopsitta monachus, at a range of spatial scales, and investigate the demographic processes that generate the observed structure. Monk parakeets construct large nests that can house several pairs occupying separate chambers; these nests are often aggregated within nesting trees. We determined patterns of relatedness within compound nests, within nesting trees and between trees. Spatial autocorrelation analyses of pairwise genetic relatedness revealed fine-scale genetic structure with relatives of both sexes spatially clustered within, but not beyond, nesting trees. In addition, males were more related to males sharing their compound nests than to other males occupying the same nesting tree. By contrast, males and females within compound nests were not significantly more closely related than elsewhere in the same tree, and we found no evidence for inbreeding. Adults showed high breeding site fidelity between years despite considerable disturbance of nest sites. Natal dispersal was female-biased, but dispersal distances were relatively short with some natal philopatry observed in both sexes. Sibling coalitions, typically of males, were observed amongst both philopatric and dispersing birds. Our results show significant clustering of kin within compound nests and nesting trees resulting from limited and coordinated natal dispersal, with subsequent breeding site fidelity. The resulting genetic structure has implications for social behaviour in this unusual parrot species.
动物种群的遗传结构具有重要的行为、生态和进化意义，可能源于各种种群统计学特征。在此，我们利用实地观测数据和分子遗传学方法，在一系列空间尺度上确定入侵的和尚鹦鹉（Myiopsitta monachus）种群的遗传结构，并研究产生所观察到的结构的种群统计学过程。和尚鹦鹉建造大型巢穴，这些巢穴可容纳几对鹦鹉，每对占据单独的巢室；这些巢穴通常在筑巢树木内聚集。我们确定了复合巢内、筑巢树木内以及树木之间的亲缘关系模式。对成对遗传亲缘关系的空间自相关分析揭示了精细尺度的遗传结构，即两性亲属在筑巢树木内而非之外在空间上聚集。此外，与共享复合巢的雄性相比，雄性与占据同一筑巢树的其他雄性的亲缘关系更近。相比之下，复合巢内的雄性和雌性之间的亲缘关系并不比同一棵树上的其他地方显著更密切，而且我们没有发现近亲繁殖的证据。尽管巢址受到相当大的干扰，但成年鹦鹉在不同年份间表现出较高的繁殖地点忠诚度。出生扩散存在雌性偏向，但扩散距离相对较短，并且在两性中都观察到了一定程度的出生留居现象。在留居和扩散的鸟类中都观察到了通常由雄性组成的同胞联盟。我们的结果表明，由于有限且协调的出生扩散以及随后的繁殖地点忠诚度，复合巢和筑巢树木内存在显著的亲属聚集现象。由此产生的遗传结构对这种不寻常的鹦鹉物种的社会行为具有重要意义。
