Social cohesion as a factor in the successful reintroduction of collared peccaries

Abstract

The relative importance of social relations on the success of reintroduction of social ungulates was examined using collared peccaries (Tayassu tajacu ). Three objectives of the research were to determine to what extent fidelity to release site, fidelity of individuals to the group, and other documented factors would influence the success of the reintroduction of social groups. Thirty-six peccaries, in captivity at Texas A&M University's Small Ungulate Research Facility, were studied to determine their social relations. Peccaries were divided into 6 groups subjected to 3 treatments: long-term female lineages, short-term female lineages, and unrelated females. There were 2 sub-groups per treatment. All peccaries were immobilized, ear-tagged, and radiotagged. They were observed in captivity for a month before being released at 6 different sites on welder Wildlife Refuge, in southeastern Texas. The peccaries were monitored by radio telemetry for 12 weeks to assess fidelity to release site and to group. A log transformation was conducted on data prior to analysis of variance to correct for non-normality. Treatment had a significant (P=0.0001) effect on both fidelity to the release site and fidelity to the group. Unrelated groups were more distant from the release sites and individuals were further apart on the average, compared to the short- and long-term female lineages. However, there was significant (P=0.0001) variation among 6 groups, and the pattern differed for each group over time (group x week; P=0.0001). Variation among groups could not be attributed to differences in social behavior in captivity. Groups did not differ significantly (P>0.05) in frequency of aggressive interactions. Replicate groups differed significantly (P<0.05) in frequency of friendly interactions within the treatments of short-term female lineages and the unrelated groups. Contrary to predictions, the mean of friendly interactions was higher for the unrelated groups than for the long-term female lineages. Success of related female groups appeared more related to the resources available at the release site and the circumstances of accommodation to the release site than to the duration females were together prior to release.