title: Biotic and abiotic factors predicting the global distribution and population density of an invasive large mammal.
abstract: Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal with a global distribution. Incorporating diverse biotic factors, including agriculture, vegetation cover, and large carnivore richness, into species distribution modeling substantially improved model fit and predictions. Abiotic factors, including precipitation and potential evapotranspiration, were also important predictors. The predictive map of population density revealed wide-ranging potential for an invasive large mammal to expand its distribution globally. This information can be used to proactively create conservation/management plans to control future invasions. Our study demonstrates that the ongoing paradigm shift, which recognizes that both biotic and abiotic factors shape species distributions across broad scales, can be advanced by incorporating diverse biotic factors.
authors.affiliation: Conservation Science Partners, 5 Old Town Sq, Suite 205, Fort Collins, Colorado, 80524, USA.
authors.forename: Jesse S
authors.initials: JS
authors.lastname: Lewis
authors.affiliation: Conservation Science Partners, 5 Old Town Sq, Suite 205, Fort Collins, Colorado, 80524, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Farnsworth
authors.affiliation: Colorado State University, Department of Biology, Fort Collins, Colorado, 80524, USA.
authors.forename: Chris L
authors.initials: CL
authors.lastname: Burdett
authors.affiliation: Conservation Science Partners, 5 Old Town Sq, Suite 205, Fort Collins, Colorado, 80524, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Theobald
authors.affiliation: Conservation Science Partners, 11050 Pioneer Trail, Suite 202, Truckee, California, 96161, USA.
authors.forename: Miranda
authors.initials: M
authors.lastname: Gray
authors.affiliation: United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, Fort Collins, Colorado, 80524, USA.
authors.forename: Ryan S
authors.initials: RS
authors.lastname: Miller
mesh_terms: D000818:Animals; D058865:Introduced Species; D008954:Models, Biological; D011157:Population Dynamics; D034421:Sus scrofa / Q000502:physiology*