Global Rewilding Potential
Dr Scott Jarvie1
1Aarhus University, Aarhus C , Denmark
Humans have caused species extinctions and range contractions that might be comparable in rate to mass extinctions. A novel and promising approach to restore lost functional and phylogenetic diversity from human caused extinctions and range contractions is trophic rewilding, the (re)introduction of species to promote self-sustaining biodiverse ecosystems. To date, there has been little quantitative research into trophic rewilding and no study has examined the global potential of rewilding. We use the recently assembled PHYLACINE atlas, a phylogeny of all late-Quaternary mammals with extensive functional data and range maps, to investigate the potential of trophic rewilding to restore lost Ice Age biodiversity using (re)introductions of still extant species or close relatives of extinct species, i.e., a phylogenetically constrained approach. Using estimated range maps of where mammals would live today without the influence of Homo sapiens, we identified extant terrestrial mammals for rewilding based on how closely related and similar in function they were to missing species and whether target rewilding locations fell within their climatic tolerance. We found that ca. 66% of missing terrestrial mammal biodiversity can be restored by reintroductions of extant taxa into their former range, with an additional ca. 13% restored by introductions of closely related ecological replacements. Our model reveals regions around the world where phylogenetically constrained trophic rewilding can restore the most missing biodiversity (Asia and Africa) as well as highlights the limits of restoration achievable through trophic rewilding (lower recovery in the Americas and Australia) without using distantly related functional analogs of extinct species.
During my PhD at the University of Otago, I studied the reintroduction biology of tuatara, the last surviving member of the reptilian order Rhynchocephalia. I used correlative and mechanistic species distribution models to identify suitable translocation sites under changing climates. I also studied captive animals and wild populations to inform and validate the mechanistic model, as well as identified suitable founder animals through an experimental reintroduction.