Abstract
Aim When introduced species invade new environments, they often overlap
with native species currently occupying those spaces, either spatially
through suitable habitat or environmentally through their realized
niches. The goal of this research is to determine the overlap between
native New England cottontail (Sylvilagus transitionalis) and introduced
eastern cottontail (Sylvilagus floridanus) to identify potential areas
of invasion by the eastern cottontail and potential areas of refuge for
New England cottontail from eastern cottontail. Location Connecticut,
USA Methods Using presence data from a regional, standardized monitoring
protocol, we developed habitat suitability models using Maxent and
conducted niche overlap analyses using Principal Component Analysis. We
used several covariates that reflected proximity to habitat
characteristics, such as young forest, shrubland, and understory, as
well as proximity to threats, such as development. We also included
topographic and climatic covariates. We used the Guidos software to
categorize the spatial arrangement of young forest, shrubland, and
understory vegetation. Results We found that the overlap in both niches
and suitable habitat was high for two species. Only areas of low
precipitation and high elevation shifted niches in favor of New England
cottontail. We also found that habitat suitability for New England
cottontail was higher when patches of mature forest without understory
were within complexes of young forest, shrubland, and mature forest with
understory. Main Conclusions Increasing habitat heterogeneity could
improve the habitat suitability of existing patches or create new
patches for New England cottontail. However, habitat management alone is
likely not enough to discourage eastern cottontail, thus direct species
management such as removal of eastern cottontail and augmentation of New
England cottontail populations should be explored.