Cynthia Elizalde-Arellano

Home Range Size and Activity Patterns of Bobcats (Lynx rufus) in the Southern Part of their Range in the Chihuahuan Desert, Mexico

Abstract Home range size, daily travel distances, and diel activity patterns are important characteristics of how an animal uses its home range area. In species, such as the bobcat (Lynx rufus), with large geographical ranges, it is necessary to gather data on diverse populations across the range to better understand what might be factors influencing these home range parameters. Although there are many studies of bobcats in more northern areas of its range in the United States, few data exist from its extensive southern range in Mexico. To fill this gap in information, we collected data on home range size, daily travel distances, and diel activity patterns of bobcats from the center of the Chihuahuan Desert in Mexico. We compared our findings with available data from more northern studies and tested for any latitudinal trends in home range size. We trapped eight adult bobcats (four females and four males) between 2006 and 2008 at the Mapimi Biosphere Reserve in the Chihuahuan Desert. Each bobcat was equipped with a GPS radio collar that estimated their location and ambient temperature every half hour at night (1900 to 800 h), and every hour during the day (800 to 1900 h). These data were used to estimate total daily distance traveled, average speed, home range size, activity pattern, and to test for an association between hourly travel and ambient temperature. For bobcats in Mapimi, mean distances traveled daily (4.9 ± 0.7 km), mean speed (0.3 ± 0.4 km/h) and average home range size (25.9 km2 ± 3.7) did not differ from other places in U.S. (distance traveled daily 5.7 ± 1.4 km, mean speed 0.4 ± 0.4 km/h and home range size 34.0 ± 5.4 km2). Bobcats are most active from 1700 to 2300 h and from 0500 to 1200 h and showed a minimum activity period from 1300 to 1600 h. These patterns did not differ from what other studies found. Distance traveled was inversely correlated with environmental temperature (r2  =  0.506, P < 0.05). Our data demonstrate that most behaviors of bobcats in this hot desert environment did not differ in general from their more northern populations. Although our home range estimates were similar to other studies, our analysis did support a latitudinal decreasing trend that indicates factors other than those related to latitude are affecting home range size in bobcats. We suggest investigating other independent factors not related with latitude such as primary production and rainfall might help identify which, if any, of these factors contribute to home range size in bobcats.

Foraging of the bobcat (Lynx rufus) in the Chihuahuan Desert: generalist or specialist?

Abstract We studied the diet and foraging behavior of bobcats (Lynx rufus) in the Chihuahuan Desert, Mexico, from 2005–2007 to test if bobcats will select energetically profitable prey, regardless of their relative abundance. We estimated frequency of occurrence and percentage of occurrence for species of prey in the diet through analysis of scats (n = 117) and evaluated selection of prey by comparing availability against consumption, based on biomass and number of prey consumed as represented in scats. Bobcats consumed a wide variety of prey, but rodents and lagomorphs dominated the diet. Species of prey were not consumed according to availability; combined lagomorphs had the highest probability of being selected based on densities and biomass despite their lower availability. Within lagomorphs, based on their availability, rabbits (Sylvilagus audubonii) were selected more often than jackrabbits. By analyzing the availability and biomass of prey against its consumption, we determined that bobcats do not select prey for high availability but act as specialist foragers. Foraging theory provides the best explanation of dietary selection by bobcats in our study area.