Sex-biased dispersal patterns of a social passerine: complementary approaches and evidence for a role of spatial scale

Abstract

Animal dispersal patterns have important implications for many biological processes, but the measurement of dispersal is challenging and often requires the use of complementary approaches. In this study, we investigated the local-scale sex-biased dispersal pattern in a social bird, the black-throated tit (Aegithalos concinnus), in central China. Spatial genetic autocorrelation analyses suggested that significant fine-scale genetic structure existed in males but not in females. Mark–recapture analyses of ringed individuals also showed that female offspring were more dispersive than male offspring, supporting genetic evidence of local female-biased dispersal. These results were contrary to a previous finding of male-biased long-distance dispersal in this species that was based on analyses of gene flow across the species range in China. This implies that the species might potentially have a scale-dependent dispersal strategy, with females frequently dispersing further than males at the local level, but with a proportion of males occasionally dispersing over long distances and contributing more to gene flow at a larger geographical scale. Long-distance dispersal by male black-throated tits might be induced by competition for resources or by unfavourable environmental conditions, warranting further investigation, but our findings increase the evidence that geographical scale is an important factor to be considered when investigating animal dispersal patterns.

Fine-scale genetic structure and phenotypic divergence of a passerine bird population inhabiting a continuous Mediterranean woodland

“…This pattern was mainly driven by non-random dispersal-as suggested by both the genetic and the capture-mark-recapture data-associated with environmental heterogeneity within the woodland. Previous studies already showed that capture-mark-recapture data provide accurate information on recent levels of gene flow among bird populations [16,18,30,[66][67][68]; but see [69]. Widespread highly mobile species are likely to experience several environmental conditions and geographical barriers, and thus, they are expected to experience genetic population structure at large geographical scales [70][71][72][73], often following an isolation-by-distance pattern (e.g.…”

Estimating nest‐switching in free‐ranging wild birds: an assessment of the most common methodologies, illustrated in the White Stork (Ciconia ciconia)

“…2018, Li et al . 2019); in others, they did not match (Robinson & Jones 2014), were not compared (e.g. Carey et al .…”