We used a spatially explicit population model of wolves (Canis

Aim Coyote (Canis latrans) distribution in Mexico and Central America has expanded recently reaching the Yucatan peninsula, Belize and Panama, probably promoted by deforestation of tropical areas. Historically, the southern distribution of coyotes prior to European settlement in America was described as reaching only as far south as central Mexico and that introduction of livestock favoured migration of coyotes to southern Mexico and Central America. However, coyote fossil records in Central America and Yucatan, as well as observational records of travellers during the sixteenth century suggest that the coyote's arrival to the region was earlier. Because of the uncertainty of past coyote distribution and the possible economic and ecological impacts due to recent range expansion, the objectives of this study were to confirm if paleontological and historical evidence support the hypothesis that the southernmost limit of coyote distribution before the arrival of European settlers was the centre of Mexico, to discuss the possible factors that have influenced historical shifts in coyote distribution, and to model the present distribution of the coyote in Mexico and Central America, determining the areas where they could invade in the near future.

There are three species of Neotropical cats whose northernmost distribution reaches the USA-Mexico border region: the jaguar Panthera onca, ocelot Leopardus pardalis and jaguarundi Herpailurus yagouaroundi. To ensure the long-term viability of Neotropical cat populations in this region it is imperative to identify current distribution and status in the northern limits of their range to conserve important populations effectively. The purpose of this study was to construct a blueprint of priority conservation areas for each species in the border region. This was done by (1) compiling reliable sightings for each species from the early 1900s to 2003, (2) conducting field surveys to ascertain species presence, and (3) conducting a geographical information system based habitat mapping workshop in which 29 scientists and conservationists provided information on the distribution and status of each species. Participants were asked to delineate and describe specific areas in the border region where historical and recent sightings of Neotropical cats have occurred, resulting in a compilation of 864 felid sightings of which 283 where reliable and had physical evidence. Twenty-one Cat Conservation Units and seven Cat Conservation Corridors were identified as areas in which to concentrate efforts for protecting felids. Only 8.9% of these Corridors and 1.1% of the Units currently have any protection. An additional 12 Corridors and 12 Units were identified as areas requiring further study.

The effect of an open landfill and the seasonality of a tropical deciduous forest in Jalisco, Mexico, was tested on the home range and group size of coyotes Canis latrans under the Resource Dispersion Hypothesis (RDH), which proposes that in social carnivores dispersion of patches of limited resources determines home-range size, whereas independently, abundance of resources affects group size. The predictions in this study were that coyotes using the landfill, where food is available all year due to the continuous arrival of food wastes that are concentrated in a single patch, would have smaller, seasonally constant home ranges than coyotes living outside, where food is distributed in several patches. In this area, coyotes would increase their home ranges during the dry season due to seasonal changes in resource availability. Also, a larger coyote group size should exist in the landfill, where food abundance is greater. Home-range size and group size of coyotes living in and outside the landfill were estimated by radio-tracking. Home ranges of coyotes in the landfill varied from 0.9 to 9.5 km 2 , whereas home-range sizes of coyotes outside the landfill varied from 10.9 to 43.7 km 2 . Seasonality had no effect on the home-range sizes. We identified a group of four adult coyotes in the landfill and no group formation in coyotes outside. These results support the predictions about home-range and group size of coyotes in relation to landfill presence, and indicate that under the circumstances of our study, coyotes follow the postulates proposed by the RDH.

We present the first study that evaluates jaguar-puma interactions in the arid lands of northern Mexico, where jaguars have their northernmost breeding population and both predators are persecuted for livestock depredation. We tested whether jaguars are the dominant species in this unique ecosystem, where: (1) pumas outnumber jaguars, (2) pumas are better adapted to arid environments, and (3) jaguars and pumas are of similar size. We analyzed four years of data with two approaches; a two species conditional occupancy model and an activity patterns analysis. We used camera location and prey presence as covariates for jaguar and puma detection and presence probabilities. We also explored overlap in activities of predators and prey. Where both species were detected, peccary presence was positively correlated with both jaguar and puma presence, whereas in areas where jaguars were detected but pumas were not, deer presence explained the probability of jaguar presence. We found that both predators were more likely to co-occur together than to be found independently, and so we rejected the hypothesis that jaguars were the dominant species in our study area. Predators were mainly nocturnal and their activity patterns overlapped by 60%. Jaguar, as compared with puma, overlapped more with deer and calves; puma overlapped with calves more than with other prey, suggesting a preference. We believe exploring predator relationships at different scales may help elucidate mechanisms that regulate their coexistence.