Data from: Modeling and mapping the probability of occurrence of invasive wild pigs across the contiguous United States

Wild pigs (Sus scrofa), also known as wild swine, feral pigs, or feral
hogs, are one of the most widespread and successful invasive species
around the world. Wild pigs have been linked to extensive and costly
agricultural damage and present a serious threat to plant and animal
communities due to their rooting behavior and omnivorous diet. We modeled
the current distribution of wild pigs in the United States to better
understand the physiological and ecological factors that may determine
their invasive potential and to guide future study and eradication
efforts. Using national-scale wild pig occurrence data reported between
1982 and 2012 by wildlife management professionals, we estimated the
probability of wild pig occurrence across the United States using a
logistic discrimination function and environmental covariates hypothesized
to influence the distribution of the species. Our results suggest the
distribution of wild pigs in the U.S. was most strongly limited by cold
temperatures and availability of water, and that they were most likely to
occur where potential home ranges had higher habitat heterogeneity,
providing access to multiple key resources including water, forage, and
cover. High probability of occurrence was also associated with frequent
high temperatures, up to a high threshold. However, this pattern is driven
by pigs' historic distribution in warm climates of the southern U.S.
Further study of pigs' ability to persist in cold northern climates
is needed to better understand whether low temperatures actually limit
their distribution. Our model highlights areas at risk of invasion as
those with habitat conditions similar to those found in pigs' current
range that are also near current populations. This study provides a
macro-scale approach to generalist species distribution modeling that is
applicable to other generalist and invasive species.