Ecology and Social Behavior of the Collared Peccary in Big Bend National Park, Texas
Bissonette JA. 1982. Ecology and Social Behavior of the Collared Peccary in Big Bend National Park, Texas. National Park Service Scientific Monograph Series. No. 16. National Park Service. Washington, D.C.
Collared peccaries are social animals and interesting biologically for many reasons. A behavioral and ecological study was conducted in the Park on collared peccaries for 23 months. Five groups were studied for 380 hours. Activity patterns, correlated strongly with temperature, consisted primarily of feeding and resting. The peccaries were most active while feeding. Contact interactions comprised over 66% of all interactions; less than 44% of all interactions were aggressive, and, of these, less than 18% were contact interactions. Peccaries hold group territories, with little or no overlap by adjacent groups. The vegetation and rocks of the territory were marked with scent gland excretions, and scat piles were found along boundary lines. The dominance hierarchy included both sexes; dominant animals were always male, with males and females in lower positions determined by size. Parturition was seasonal and correlated with the onset of heavy rainfall. The mean litter size per female was 1.3 young. Mortality was high in every group studied, ranging between 50 to 100% per year of all young produced, with the highest mortality in the poorest ranges. Recruitment was relatively low in all herds. Sex ratios did not differ significantly from 1:1. Habitats with dense vegetation were used more in the summer, whereas the more open areas were used more in the winter. Ranges at higher elevations contained preferred forage. Territorial groups size was found to be positively correlated with percent vegetative cover and percent composition of prickly pear, lecheguilla, and forbs, but negatively correlated with percent woody cover. Predictions of carrying capacity can be made by assessment of range cover and percent composition of preferred forage species. Lecheguilla was the most abundant preferred food, prickly pear the second. Use of available food sources was low; use of prickly pear varies from 1.7 to 5.4%, and use of lecheguilla was about 2.6%.