RESUMO
Monitoring the invasive exotic species and their effect on native fauna is fundamental for their effective control. The objective of this research is to evaluate the spatiotemporal distribution and overlap of medium-large-sized fauna in El Palmar National Park, Argentina, to consider potential negative interactions between native and exotic species. Camera traps were distributed in 27 sites between 2017 and 2019. Spatial and temporal overlap was estimated for every pair of exotic-native taxa. With 2673 camera days, two exotic and seven native taxa were recorded. All species were distributed along the extension of the National Park but in different numbers of sites. Exotic axis deer (Axis axis) was recorded in all sites but one, and exotic wild boar (Sus scrofa) occurred at only one-third of the sites surveyed. The occurrence of native mammals ranged between 26% (Geoffroy's cat, Leopardus geoffroyi) and 67% (capybara, Hydrochoerus hydrochaeris). Spatial overlap between native and exotic species was high overall and was higher in winter when species moved over larger areas to look for limited resources. Except for greater rhea (Rhea americana), which was diurnal, all species had crepuscular or nocturnal patterns. Both exotic species had an intermediate/high overlap in their activity pattern with almost all native species, including some species with similar diets, but the hours of their maximum activities did not strictly coincide. However, the existence of differences in the exotic species' activity patterns compared to their patterns in other areas where they inhabit could indicate segregation in daily activity to relax competition.
RESUMO
During the 20th century, there has been an ongoing agricultural expansion and global warming, two of the main determinants influencing biodiversity changes in Argentina. The red hocicudo mouse (Oxymycterus rufus) inhabits subtropical grasslands and riparian habitats and has increased its abundance in recent years in central Argentina agroecosystems. This paper describes the long-term temporal changes in O. rufus abundance in Exaltación de la Cruz department, Buenos Aires province, Argentina, in relation to weather fluctuations and landscape features, as well as analyzes the spatio-temporal structure of captures of animals. We used generalized liner models, semivariograms, the Mantel test, and autocorrelation functions for the analysis of rodent data obtained from trappings conducted between 1984 and 2014. O. rufus showed an increase in abundance across the years of study, with its distribution depending on landscape features, such as habitat types and the distance to floodplains. Capture rates showed a spatio-temporal aggregation, suggesting expansion from previously occupied sites. O. rufus was more abundant at lower minimum temperatures in summer, higher precipitation in spring and summer, and lower precipitations in winter. Weather conditions affected O. rufus abundance, but there was local variation that differed from global patterns of climate change.