title: Climate change promotes hybridisation between deeply divergent species.
abstract: Rare hybridisations between deeply divergent animal species have been reported for decades in a wide range of taxa, but have often remained unexplained, mainly considered chance events and reported as anecdotal. Here, we combine field observations with long-term data concerning natural hybridisations, climate, land-use, and field-validated species distribution models for two deeply divergent and naturally sympatric toad species in Europe (Bufo bufoandBufotes viridisspecies groups). We show that climate warming and seasonal extreme temperatures are conspiring to set the scene for these maladaptive hybridisations, by differentially affecting life-history traits of both species. Our results identify and provide evidence of an ultimate cause for such events, and reveal that the potential influence of climate change on interspecific hybridisations goes far beyond closely related species. Furthermore, climate projections suggest that the chances for these events will steadily increase in the near future.
authors.affiliation: Department of Ecological and Biological Science, Università degli Studi della Tuscia , Viterbo , Italy.
authors.forename: Daniele
authors.identifier: 0000-0001-9351-4972
authors.initials: D
authors.lastname: Canestrelli
authors.affiliation: Department of Ecological and Biological Science, Università degli Studi della Tuscia , Viterbo , Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Bisconti
authors.affiliation: Department of Ecological and Biological Science, Università degli Studi della Tuscia , Viterbo , Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Chiocchio
authors.affiliation: Department of Biology and Biotechnology 'Charles Darwin', University of Roma 'La Sapienza', Rome, Italy; Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy.
authors.forename: Luigi
authors.identifier: 0000-0002-2957-8979
authors.initials: L
authors.lastname: Maiorano
authors.affiliation: Department of Ecological and Biological Science, Università degli Studi della Tuscia , Viterbo , Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Zampiglia
authors.affiliation: Department of Ecological and Biological Science, Università degli Studi della Tuscia , Viterbo , Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nascetti
keywords: Climate change; Hybridisation; Life-history traits; Pre-mating reproductive barriers