Data from: Survival and causes of mortality of introduced wild pigs in the presence of cougars

Wild pigs (Sus scrofa) are an introduced species that affect ecosystems
through myriad pathways. They are the target of population control
efforts, but one outstanding question is the extent to which native
predators affect population demography. Cougars (Puma concolor) are a
known predator of wild pigs and cooccur with wild pigs in several regions
of the Americas. However, investigations of wild pig survival in regions
with cougars are lacking. We investigated the survival and causes of
mortality for wild pigs in California, USA where cougars could act as a
predator. We also explored habitat selection of wild pigs with respect to
cougar predation risk. We collared 69 wild pigs, 15 adults, 15 subadults,
and 39 juveniles. Captures occurred in winter and spring and survival
estimates primarily reflect spring and summer survival. We estimated
6-month survival of adults and juveniles to be 0.923 (95% confidence
interval: 0.789 – 1.00) and 0.563 (0.416 – 0.762), respectively, which are
similar to estimates from areas without cougars. Only juvenile and one
subadult wild pig were killed by cougars, suggesting that cougars are a
limited predator of adults. We also investigated feeding locations of 3
GPS-collared cougars to generate a spatial layer of cougar kill
occurrence. We used this layer in an integrated step selection function
for wild pigs and observed wild pigs selecting areas with low probability
of cougar kill occurrence during times when cougars are most active.
Combined, these results suggest that cougars are a minor source of
mortality for wild pigs during the spring and summer and may be unlikely
to provide substantial biological resistance against the spread of wild
pigs. Our monitoring occurred when native prey (e.g. ungulate neonates)
are most abundant which may influence cougar predation of pigs. It is
likely that a preference for native prey, the novelty of wild pigs, wild
pig habitat selection, and the potential danger of adult wild pigs reduces
cougar predation.