Aerial Landscape Genetics: Environmental drivers of dispersal patterns in the Andean condor

PADRO JULIAN; SERGIO LAMBERTUCCI; ALARCÓN, PABLO A. E.; JOHANNES SIGNER; NIKO BALKENHOL

cACERES

Conferencia; 2 nd   European Vulture Conference; 2023

Understanding how dispersal patterns are influenced by landscape heterogeneity is critical not only for modeling species connectivity, but also for designing conservation plans and protected areas. Although landscape genetic models are increasingly used in terrestrial and aquatic habitats, they are virtually ignored in aerial environments. This is especially important for obligate soaring birds like vultures which depend on the energy provided by the landscape to move across vast regions. In this work, we estimated contemporary gene-flow rates among Andean condors (Vultur gryphus) inhabiting different biomes between the Andean range and the central mountains of Argentina. We used maximum likelihood estimations of isolation-by-resistance models, where conductance is a function of a combination of static and dynamic landscape features hypothesized to influence dispersal in condors, and the observed data are the genetic distances between sampling regions. In addition, we derived landscape resistance surfaces from movement data, using Resource Selection Function, to test the influence of the landscape on different movement behaviors. We found that gene-flow was correlated with the Topographic Position Index (valleys), steep slopes, aspect (northwest face), orographic uplift in winter, and south-north winds in summer. Our model depicting the present functional connectivity of condors in central Argentina showed a large high-connectivity corridor along the Andean range partially isolated from the central mountains which were more connected to the northern portion of the Andes through a stepping-stone mosaic. Landscape features differentially affected resource selection, suggesting that some landscape features are important for some flight behaviors but not for others, and are seasonally dependent. This work highlights that consideration of both habitat selection and landscape genetics models may be useful in developing more comprehensive conservation plans that take into account the complex spatial and temporal habitat requirements of wide-ranging species like vultures.