Intrinsic factors drive spatial genetic variation in a highly vagile species, the wedge‐tailed eagle Aquila audax, in Tasmania

Abstract

Knowledge of dispersal in a species, both its quantity and the factors influencing it, are crucial for our understanding of ecology and evolution, and for species conservation. Here we quantified and formally assessed the potential contribution of extrinsic factors on individual dispersal in the threatened Tasmanian population of wedge-tailed eagle Aquila audax. As successful breeding by these individuals appears strongly related to habitat, we tested the effect of landscape around sampling sites on genetic diversity and spatial genetic variation, as these are influenced by patterns of dispersal. Similarly, we also tested whether habitat intervening sampling sites could explain spatial genetic variation. Twenty microsatellites were scored, but only a small proportion of spatial genetic variation (4.6%) could be explained by extrinsic factors, namely habitat suitability and elevation between sites. However, significant clinal genetic variation was evident across Tasmania, which we explain by intrinsic factors, likely high natal philopatry and occasional long-distance dispersal. This study demonstrates that spatial genetic variation can be detected in highly vagile species at spatial scales that are small relative to putative dispersal ability, although here there was no substantial relationship with landscape factors tested.

Conservation genetics of regionally extinct peregrine falcons (Falco peregrinus) and unassisted recovery without genetic bottleneck in southern England

“…There are several possible intrinsic and extrinsic factors, such as dispersal (natal and breeding), life history, behaviour, habitat and connectivity (Kozakiewicz et al 2017), influencing the genetic composition of the newly re-established Sussex population. It is possible that not enough time elapsed for genetic erosion to occur or to be observed after the population bottleneck (Hailer et al 2006;Johnson et al 2010;Ponnikas et al 2017).…”

Under‐representation of avian studies in landscape genetics

“…Kozakiewicz et al . ). Likewise, explicit statements within papers that have been reframed as more traditional ‘population genetic’ studies are required to avoid biasing our understanding of landscape influence on genetic variation within birds through the ‘file‐drawer’ problem (Rosenthal ).…”

“…This presumes that such analyses have not been conducted before, and we encourage studies that fail to detect landscape influence on genetic patterns to be documented as formal papers with 'negative' results (e.g. Kozakiewicz et al 2017). Likewise, explicit statements within papers that have been reframed as more traditional 'population genetic' studies are required to avoid biasing our understanding of landscape influence on genetic variation within birds through the 'filedrawer' problem (Rosenthal 1979).…”

Integrating functional connectivity and fire management for better conservation outcomes

“…2015); (b) wedge‐tailed eagle ( Aquila audax ) responds at larger spatial scales (Kozakiewicz et al. 2017); (c) eastern chestnut mouse ( Pseudomys gracilicaudatus ) responds to both landscape structure and fire at smaller spatial scales (Pereoglou et al. 2013); and (d) eastern gray kangaroo ( Macropus giganteus ) responds at larger spatial scales (Styger et al.…”