Octavio C. Rosas-Rosas

Jaguar and Puma Predation on Cattle Calves in Northeastern Sonora, Mexico

Abstract Predation by jaguars (Panthera onca) and pumas (Puma concolor) is often a source of conflict with cattle ranching in northeastern Sonora, Mexico. Because jaguars are endangered in Mexico, such conflicts have biological, social, and economic consequences. We documented the extent of predation by jaguars and pumas on cattle in 1999–2004 in northeastern Sonora, where the northernmost breeding population of jaguars exists in North America. Jaguars and pumas killed only calves < 12 mo old, and calves constituted 58% of prey biomass consumed by jaguars and 9% by pumas. Annual cause-specific mortality rates of confirmed jaguar predation (≤ 0.018), confirmed and suspected jaguar predation (≤ 0.018), and all confirmed and suspected large felid predation (≤ 0.018) were low and cattle calf survival was high (0.89–0.98 annually). If calves reported as missing but for which no evidence of mortality could be found were classed as large felid predation, annual cause-specific rates increased to 0.006–0.038. Collectively, confirmed jaguar and puma predation accounted for < 14% (57/408) of total cattle losses, with jaguars responsible for 14% of all calf losses; this could increase to a maximum of 36% (146/408) if missing calves were included in the totals. While jaguar and puma predation may have an impact on some small cattle operations, it is generally minor compared to losses from other causes in northeastern Sonora. Moreover, 91% of all confirmed calf kills were associated with three individual jaguars in our study. Targeting problem cats rather than broad-scale predator control may therefore be a viable alternative to address chronic predation problems. Because most (83%) instances of jaguar predation occurred during the dry season along thick riparian habitats, modified cattle husbandry operations, such as establishment of permanent water sources in uplands and away from dense vegetative cover, could ameliorate many cases of predation by jaguars on cattle.

The Role of Landowners in Jaguar Conservation in Sonora, Mexico

The northernmost known breeding population of jaguars occurs in the municipality of Nácori Chico, Sonora, Mexico about 270 km from the United States-Mexico border and may be the source from which jaguars sighted in the United States dispersed. Since 1999 at least 11 jaguars (Panthera onca) had been illegally killed in the area due to predator control programs. We initiated a jaguar landowner-based conservation plan in 2004. The eight participating landowners agreed to suspend predator control programs targeting jaguars and pumas (Puma concolor) only if cattle losses were compensated. A private outfitter, with the consent of landowners, initiated white-tailed deer (Odocoileus virginianus) hunts in 2004 and agreed to pay the group of participating landowners US

Food Habits of Jaguar and Puma in a Protected Area and Adjacent Fragmented Landscape of Northeastern Mexico

1500 for every deer hunt permit sold. The funds paid to the landowners from deer hunts were sufficient to convince landowners to suspend all predator-control efforts of jaguars and pumas. The involvement of landowners in the jaguar conservation program in northeastern Sonora is a successful, private, wildlife-conservation initiative that provides an example for jaguar conservation efforts in northern Mexico.

The Jaguar (Panthera onca) in San Luis Potosí, Mexico

ABSTRACT: We analyzed the food habits of the jaguar (Panthera onca) and puma (Puma concolor) in a protected area surrounded by a fragmented landscape in northeastern Mexico. We estimated relative biomass of each prey species consumed; by analysis of 43 and 22 scat samples of jaguar and puma collected during 2010–2012. The diet of both felids was comprised mainly of wild artiodactyls; the collared peccary contributed 35.2% to the biomass of jaguar diets and white-tailed deer contributed 51.9% to puma diets. Diet composition of both felids showed moderate overlap (Pianka index = 0.57; Morisita index = 0.58), but use of the primary prey differed between species (P < 0.001). The diet of both felids included almost exclusively wild species, suggesting the presence of a good prey base that allows the coexistence of jaguars and pumas. Despite its small size and surrounding fragmentation, the Biosphere Reserve Sierra del Abra-Tanchipa is still an important refuge for large felids and their prey in northeastern Mexico.

Occupancy and habitat correlates of javelinas in the southern San Andres Mountains, New Mexico

Abstract Geographic range of the jaguar (Panthera onca) in Mexico has decreased due to illegal hunting, loss of prey, and loss of habitat. No survey of jaguars has been conducted in San Luis Potosí since 1953, despite potentially suitable habitat in the Sierra Madre Oriental. During May 2006–March 2008, we conducted 22 field surveys, including interviews of local officials, residents, landowners, and hunters from 42 communities, and searched for tracks near each location where jaguars were reported in the Huasteca Region of the Sierra Madre Oriental of San Luis Potosí. We obtained 34 records of jaguars, 28 considered as recent records comprising ≥12 individuals and 6 historic records. Jaguars were recorded in oak forest (31.1% of records), tropical deciduous forest (28.1%), cloud forest (12.5%), tropical forest (12.5%), piedmont scrub (9.4%), pine-oak forest (3.1%), and along a border between a sugar cane plantation and tropical forest (3.1%). Locations were 150–2,400 m in elevation. We documented presence of diverse prey and four other species of felids. We generated a distribution map for jaguars and estimated loss of forests for 1970–2000. Geographical distribution of jaguars in San Luis Potosí extends north (22°30′N) to the municipality of El Naranjo, south (21°24′N) to the municipality of Xilitla, east (98°54′W) to the municipality of Ciudad Valles, and west (99°34′W) to the municipality of Rayón. The distribution comprises the subprovince of the Gran Sierra Plegada, Carso Huasteco, and Sierra del Abra Tanchipa of the Sierra Madre Oriental. Given the number of records and quality of remaining habitat, the Sierra Madre Oriental in San Luis Potosí should be considered as a high priority for long-term conservation of jaguars in Mexico.

Compensatory puma predation on adult female mule deer in New Mexico

Abstract Javelinas (Pecari tajacu) are expanding their range northward in the southwestern United States, but little is known of habitat relationships in northern populations. We used occupancy modeling and maximum entropy modeling of data collected from a camera-trapping grid to investigate javelina occupancy and identify habitat correlates associated with presence in the southern San Andres Mountains of south-central New Mexico. Corrected for incomplete detection, occupancy increased from 0.036 (SE = 0.035) in 2007 to 0.327 (SE = 0.082) by 2011. Presence of javelinas was most strongly associated with areas in close proximity to permanent water sources; with overstory or high shrub canopies of riparian, oak–mountain mahogany, or pinyon–juniper; and with low (< 6%) slopes. Areas with P > 0.75 for javelina presence comprised only 6.7% of the San Andres landscape. Circadian patterns of behavior indicated that javelinas were primarily diurnal during colder months and nocturnal during warmer months. Expansion of javelina occupancy may be related to a slight trend in increasing minimum winter temperatures, because severe winters were hypothesized to limit the northern distribution of javelinas. Additionally, javelinas appear dependent upon a tree or shrub overstory, ideally associated with riparian corridors, to mitigate heat stress associated with occupancy of Chihuahuan Desert habitats.

Accuracy of two techniques used to estimate pronghorn (Antilocapra americana) numbers in Chihuahuan Desert rangelands

Pumas (Puma concolor) are the primary predator of adult mule deer (Odocoileus hemionus) throughout most of arid New Mexico, and predation by pumas is popularly believed to limit mule deer populations. Predation can limit population size of prey if it is primarily additive or acts in addition to other mortality factors. Thus, clarifying the impact of predation is important because of misconceptions regarding the act of predation (i.e., killing an individual) rather than the effect (i.e., effects on population demography) cloud discussions of the issue. Herein, we tested the population-level question of whether puma predation on adult female mule deer is compensatory or additive mortality in multiple mule deer populations in New Mexico. We modeled annual survival rate as a function of cause-specific mortality rate. For this conservative test, a slope = 0 indicated complete compensation, whereas a slope = –1 indicated complete additivity. For all populations, the corrected slope of predation ultimately attributable to pumas was 0.00, ultimate and proximate puma predation combined was 0.10, ultimate puma predation and unknown causes of mortality combined was –0.28, and ultimate and proximate puma predation and unknown deaths combined was –0.23. Thus, puma predation appeared primarily compensatory. Despite small sample sizes, individual populations showed similar patterns indicating the compensatory nature of puma predation. Primarily compensatory predation for mule deer reflected the relatively low condition of deer. Survival was most strongly tied to individual condition in these populations, and a priori condition of puma-predated mule deer was lower than the population means. Compensatory mortality requires predisposition whether caused by decreased condition, high population density, or other factors. If conditions that predispose individual deer to mortality are present, managers should not assume that predation is limiting, regardless of predation rates.

Effect of predation on adult pronghorn Antilocapra americana (Antilocapridae) in New Mexico, Southwestern USA

Two techniques frequently used for monitoring pronghorn populations were compared in vegetation communities of the Chihuahuan Desert in New Mexico, USA. The evaluated techniques included the walking line transect and the driving line transect under two vegetation types and relative to season. The true population value (control) used to evaluate the techniques was a complete census using flights conducted over the entire study area (8000 ha). On grassland vegetation, the walking transect overestimates pronghorn density (n/km2), compared with the control (0.77 vs. 0.18 n/km2), as well as in the mesquite-grassland vegetation where the walking transect overestimates density (0.26 n/km2) compared with the control (0.11 n/km2). An increase in overestimation was found in the walking technique as the number of pronghorns in an area increased. In contrast, the driving technique showed no significant differences (P>0.05) compared with the control, in both grassland and mesquite-grassland pastures. It can be concluded that driving transect sampling is an accurate method to study pronghorn densities in the Chihuahuan Desert ecosystem, while walking transect sampling estimations need to be adjusted to obtain accurate population sizes.

Seasonal occupancy of sympatric larger carnivores in the southern San Andres Mountains, south-central New Mexico, USA

Abstract The effect of predation on ungulate populations remains contentious, despite a lack of evidence showing impacts in arid Southwestern USA populations where low precipitation and frequent drought limit ungulate nutritional condition. These conditions can increase predisposition of prey to mortality, which is prerequisite for predation to be compensatory. Consequently, we tested the effect of predation on adult pronghorn Antilocapra americana (Ord 1815) in two populations in arid New Mexico by modeling transformed annual survival rates as a function of predation rates. For this conservative test, a slope=0 indicates complete compensation, whereas a slope=−1 indicates complete additivity. The corrected slope of mortality potentially attributable to predation was >−0.14, and this result was consistent among individual populations. Thus, predation was primarily compensatory. Primarily compensatory predation was related to the relatively low condition of pronghorn individuals, as predated individuals were all below the mean condition of the population, similar to results seen in previous tests of the compensatory versus additive predation hypothesis in the arid Southwest USA. Conditions that predispose individual ungulates to mortality are present more often than not in arid environments, and thus managers should not assume that predation is limiting, regardless of predation rates.

Food habits of pumas in northwestern Sonora, Mexico

We investigated factors facilitating coexistence of pumas (Puma concolor), coyotes (Canis latrans), and bobcats (Lynx rufus) in the arid San Andres Mountains of south-central New Mexico, during the season (winter and spring, prior to the annual monsoon) of greatest resource stress. We established a camera-trapping grid in the San Andres, 2007–2011, and modeled occupancy of the three carnivores as a function of habitat, prey, and presence of the other carnivore species. Species interaction factors were >1.3 for each pair of carnivores, and the presence of the other carnivore species never significantly influenced occupancy of any other carnivore. Similarly, occupancy of the San Andres landscape was positively correlated among all carnivores. Occupancy of pumas was most influenced by proximity of water; coyote occupancy was influenced by terrain ruggedness and presence of medium (primarily lagomorph) prey, and bobcat occupancy was influence primarily small prey and proximity to water. The three carnivores also did not show temporal partitioning in use of habitats. Rather than segregation driven by competition, predation, or despotism, our results appeared to reflect preferences for differing habitat characteristics between ambush and cursorial predators and preferred habitats for travel.