title: Realized niche shift during a global biological invasion.
abstract: Accurate forecasts of biological invasions are crucial for managing invasion risk but are hampered by niche shifts resulting from evolved environmental tolerances (fundamental niche shifts) or the presence of novel biotic and abiotic conditions in the invaded range (realized niche shifts). Distinguishing between these kinds of niche shifts is impossible with traditional, correlative approaches to invasion forecasts, which exclusively consider the realized niche. Here we overcome this challenge by combining a physiologically mechanistic model of the fundamental niche with correlative models based on the realized niche to study the global invasion of the cane toad Rhinella marina. We find strong evidence that the success of R. marina in Australia reflects a shift in the species' realized niche, as opposed to evolutionary shifts in range-limiting traits. Our results demonstrate that R. marina does not fill its fundamental niche in its native South American range and that areas of niche unfilling coincide with the presence of a closely related species with which R. marina hybridizes. Conversely, in Australia, where coevolved taxa are absent, R. marina largely fills its fundamental niche in areas behind the invasion front. The general approach taken here of contrasting fundamental and realized niche models provides key insights into the role of biotic interactions in shaping range limits and can inform effective management strategies not only for invasive species but also for assisted colonization under climate change.
authors: School of Botany, The University of Melbourne, VIC 3010, Australia; reid.tingley@unimelb.edu.au.
authors: Reid
authors: R
authors: Tingley
authors: Instituto de Estudos Costeiros, Laboratório de Evolução, Universidade Federal do Pará, Campus de Bragança, CEP 68.600-000, Pará, Brasil;Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; and.
authors: Marcelo
authors: M
authors: Vallinoto
authors: Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; and.
authors: Fernando
authors: F
authors: Sequeira
authors: Department of Zoology, The University of Melbourne, VIC 3010, Australia.
authors: Michael R
authors: MR
authors: Kearney
mesh_terms: D000818:Animals; D001315:Australia; D002024:Bufo marinus / Q000502:physiology*; D057231:Climate Change; D017753:Ecosystem; D058865:Introduced Species; D008954:Models, Biological
keywords: Bufo marinus; Maxent; biophysical model; range shift; species distribution model