Spatial genetic patterns in African wild dogs reveal signs of effective dispersal across southern Africa

Tensen, Laura; Vuuren, Bettine Jansen van; Groom, Rosemary J.; Bertola, Laura D.; Iongh, Hans de; Rasmussen, Gregory S. A.; Plessis, Cole du; Davies‐Mostert, Harriet T.; Merwe, D. van der; Fabiano, Ezequiel; Lages, Fernanda; Rocha, Filipe; Monterroso, Pedro; Godinho, Raquel

doi:10.3389/fevo.2022.992389

Cited by 4 publications

(1 citation statement)

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“…(2012) revealed that dispersal and the associated mortality indeed led to a decline in genetic diversity and, subsequently, to a net loss of individuals. At present, our own study population appears to benefit from moderate levels of dispersal, as an analysis across Southern Africa revealed a genetically healthy cluster in the Kavango‐Zambezi Transfrontier Conservation Area (Tensen et al., 2022). This cluster may, however, be at risk depending on future flood conditions.…”

Section: Discussionmentioning

confidence: 77%

Dispersal and connectivity in increasingly extreme climatic conditions

Hofmann,

Behr,

McNutt

et al. 2024

Global Change Biology

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While climate change has been shown to impact several life‐history traits of wild‐living animal populations, little is known about its effects on dispersal and connectivity. Here, we capitalize on the highly variable flooding regime of the Okavango Delta to investigate the impacts of changing environmental conditions on the dispersal and connectivity of the endangered African wild dog (Lycaon pictus). Based on remote sensed flood extents observed over 20 years, we derive two extreme flood scenarios: a minimum and a maximum flood extent, representative of very dry and very wet environmental periods. These conditions are akin to those anticipated under increased climatic variability, as it is expected under climate change. Using a movement model parameterized with GPS data from dispersing individuals, we simulate 12,000 individual dispersal trajectories across the ecosystem under both scenarios and investigate patterns of connectivity. Across the entire ecosystem, surface water coverage during maximum flood extent reduces dispersal success (i.e., the propensity of individuals to disperse between adjacent subpopulations) by 12% and increases dispersal durations by 17%. Locally, however, dispersal success diminishes by as much as 78%. Depending on the flood extent, alternative dispersal corridors emerge, some of which in the immediate vicinity of human‐dominated landscapes. Notably, under maximum flood extent, the number of dispersing trajectories moving into human‐dominated landscapes decreases by 41% at the Okavango Delta's inflow, but increases by 126% at the Delta's distal end. This may drive the amplification of human–wildlife conflict. While predicting the impacts of climate change on environmental conditions on the ground remains challenging, our results highlight that environmental change may have significant consequences for dispersal patterns and connectivity, and ultimately, population viability. Acknowledging and anticipating such impacts will be key to effective conservation strategies and to preserve vital dispersal corridors in light of climate change and other human‐related landscape alterations.

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Section: Discussionmentioning

confidence: 77%

Dispersal and connectivity in increasingly extreme climatic conditions

Hofmann,

Behr,

McNutt

et al. 2024

Global Change Biology

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Genetic surfing during the range expansion of an endangered large carnivore

Tensen,

Currat,

Davies-Mostert

et al. 2023

Biodivers Conserv

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In an effort to halt the global decline of large carnivores, reintroductions have become increasingly popular to establish satellite populations and reduce the risk of stochastic events. These artificial range expansions are typically formed by a small number of founders, which can lead to changes in population genetic structure. For instance, serial founder events can lead to neutral and even deleterious alleles reaching higher than expected frequencies along the front end of an expansion, referred to as gene surfing. One of the world’s most extensive range expansion programmes has been for endangered African wild dogs (Lycaon pictus). In this study, we examine the effect of continent-wide translocations on spatial genetic diversity, by determining what effect genetic surfing has on population structure in wild dogs, and measuring how long it will take for population structure to homogenize in the face of ongoing dispersal. We used a set of microsatellite loci to look at surfing alleles in five populations across southern Africa, and simulated the movement of these alleles forward in time under the current demographic scenario. We found that it would take about 150 generations for the expanding population to be 50% introgressed with genes from the free-roaming population. With the current rate of translocations, genetic differentiation in southern Africa will disappear, overturning the effects of genetic drift or surfing alleles. Understanding genetic patterns in expanding populations is of great interest to conservation, and we demonstrate that reintroduction programmes can help restore genetic diversity, and consequently adaptive potential, in recovering wildlife populations.

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