Contrasting patterns of natal dispersal of a south temperate House Wren population at local and regional scales

CARRO, MARIANA E.; PAULO E LLAMBIAS; MAHLER BETTINA; FERNANDEZ, GUSTAVO JAVIER

Journal fur Ornithologie

Springer

Año: 2021 p. 1 - 13

1439-0361

Dispersal constitutes one of the main processes that shape population genetic structure and dynamics. Combining a capture-mark-resighting methodology and molecular genetics analyses, we studied the natal dispersal behaviour of House Wrens (Troglodytes aedon bonariae) inhabiting a naturally fragmented habitat in south temperate Argentina. Based on data collected over 12 breeding seasons (2005?2016), we tested if males and females difer in natal dispersal behaviour at diferent spatial scales. At local scale (within study sites), both resighting of banded individuals and genetic analysis showed that females dispersed greater distances than males. At a broader spatial scale (between study sites) resighting of banded individuals could not verify that females were the dispersing sex since long-distance dispersal was rare. However, genetic analyses revealed paradoxical evidence: while the females of populations separated by more than 5 km showed slight but signiicant genotypic diferences among them, males showed genetic diferences at a greater distance (> 16 km). Given that genetic analyses can provide evidence of both historical and present-day dispersal the observed genetic diferentiation does not necessarily imply that the sex dispersal pattern is reversed at a regional scale. We propose that females have a higher probability of acquiring a partner/territory at closer distances due existing male-biased population sex ratio caused but higher female mortality. Also, although males are less likely to disperse, when they do, they must travel greater distances to ind a suitable territory or mate. Such movements would prevent the occurrence of genetic diferences among male populations.