Rates of Survival and Sources of Mortality of Cougars in Hunted Populations in North-Central Arizona (Report‪)‬

Variables potentially influencing abundance and demographics of populations of cougars (Puma concolor) include natural factors such as accidents, intraspecific behavior, abundance of ungulate prey, and human-directed variables such as hunting, predator control, and habitat loss (Seidensticker et al., 1973; Pierce et al., 2000; Logan and Sweanor, 2001). Killing by humans, particularly through sport hunting, commonly is believed to be the primary cause of mortality in hunted populations (Lindzey et al., 1988; Ruth et al., 1998; Logan and Sweanor, 2001; Lambert et al., 2006; Laundre et al., 2007). Relatively high levels of harvest potentially reduce rates of survival and abundance, and influence demographic structure of populations (Lindzey et al., 1992; Cunningham et al., 2001; Lambert et al., 2006; Stoner et al., 2006), but quantitative effects of harvest on populations remain uncertain (Logan and Sweanor, 2001; Anderson and Lindzey, 2005). Populations of cougars might be increasing in much of western North America (Riley and Malecki, 2001), but declines might occur in some locations due to hunting pressures (Anderson and Lindzey, 2005; Lambert et al., 2006; Stoner et al., 2006). Intraspecific aggression is the major cause of mortality in non-hunted populations, and relative effects of limiting factors likely shift from natural in unhunted populations to strongly human-directed in hunted populations (Sweanor, 1990; Ruth et al., 1998; Logan and Sweanor, 2001). Depredation removals may exceed sport harvests of cougars as the primary cause of mortality in an area of southeastern Arizona (Cunningham et al., 2001), and depredation removals in recent years have comprised ca. 15% of total harvest in the state (Barber, 2005). Variables such as relative abundance of prey also might influence rates of survival (Laundre et al., 2007). Moreover, researchers in California (Pierce et al., 1999, 2000) and New Mexico (Logan and Sweanor, 2001) hypothesized that food is the ultimate limiting factor in non-hunted populations. This hypothesis was supported by research on populations of cougars in relation to abundance of prey in Utah (Laundre et al., 2007). In New Mexico, although decline of the mule deer (Odocoileus henyionus) did not correspond with reduced rates of survival of adults in a non-hunted population, researchers expected a lag in the numerical response by cougars to occur (Logan and Sweanor, 2001). Such a lag was observed in studies of population dynamics of cougars and prey in Utah (Laundre et al., 2007). Previously reported estimates of rates of survival differ considerably among studies and years, but might tend to be higher in non-hunted than in hunted populations (Lindzey et al., 1988; Cunningham et al., 2001; Logan and Sweanor, 2001; Lambert et al., 2006). We studied cougars in two hunted populations to determine and compare rates of survival and causes of mortalities.