Invasion ecology of wild pigs (Sus scrofa) in Florida, USA: the role of humans in the expansion and colonization of an invasive wild ungulate

Authors

Felipe A. Hernandez, University of Florida
Brandon M. Parker, University of Florida
Cortney L. Pylant, University of Florida
Timothy J. Smyser, USDA APHIS/Wildlife Services/NWRCFollow
Antoinette J. Piaggio, USDA APHIS/Wildlife Services/NWRCFollow
Stacey L. Lance, University of GeorgiaFollow
Michael P. Milleson, USDA APHIS Wildlife Services
James D. Austin, University of FloridaFollow
Samantha M. Wisely, University of FloridaFollow

ORCID IDs

0000-0003-1748-4518

Document Type

Article

Date of this Version

2018

Citation

Biol Invasions (2018) 20:1865–1880

Comments

Copyright The Author(s) 2018.

Open access

https://doi.org/10.1007/s10530-018-1667-6

Abstract

Wild pigs (Sus scrofa) are the most widely distributed invasive wild ungulate in the United States, yet the factors that influence wild pig dispersal and colonization at the regional level are poorly understood. Our objective was to use a population genetic approach to describe patterns of dispersal and colonization among populations to gain a greater understanding of the invasion process contributing to the expansion of this species. We used 52 microsatellite loci to produce individual genotypes for 482 swine sampled at 39 locations between 2014 and 2016. Our data revealed the existence of genetically distinct subpopulations (F_ST = 0.1170, p\0.05). We found evidence of both fine-scale subdivision among the sampling locations, as well as evidence of long term genetic isolation. Several locations exhibited significant admixture (interbreeding) suggesting frequent mixing of individuals among locations; up to 14% of animals were immigrants from other populations. This pattern of admixture suggested successive rounds of human-assisted translocation and subsequent expansion across Florida. We also found evidence of genetically distinct populations that were isolated from nearby populations, suggesting recent introduction by humans. In addition, proximity to wild pig holding facilities was associated with higher migration rates and admixture, likely due to the escape or release of animals. Taken together, these results suggest that human-assisted movement plays a major role in the ecology and rapid population growth of wild pigs in Florida.