Rehabilitation method affects behavior, welfare, and adaptation potential for subsequent release of orphaned white rhinoceros

Abstract

Poaching is the primary threat to the survival of rhinoceros’ populations. One frequent consequence of poaching is the creation of orphan calves. If found, orphans are taken into captivity for rehabilitation and subsequent release. However, rehabilitation practices can influence their behavior and welfare, potentially compromising their post-release adaptation and survival. In this study, the effects of hands-off and hands-on rehabilitation methods on the behavior, welfare, and adaptation potential of orphaned white rhinoceros (Certatotherium simum simum) were compared. To achieve these aims, 12 behavioral, one physiological, and four physical indicators of welfare and adaptation potential were measured non-invasively on 25 orphaned rhino at two rehabilitation facilities in South Africa. Results indicated that although orphan welfare was not compromised under either rehabilitation method, the hands-off cohort showed fewer indicators of poor welfare and more indicators of good welfare. Regarding adaptation potential, hands-off rehabilitated rhino showed the species’ natural response to humans, and alert and defense behaviors were part of their behavioral repertoire. The hands-on cohort displayed fewer social interactions than the hands-off cohort, showed habituation to humans, and seldom expressed alert or defense behaviors, which could potentially compromise their survival and social integration after release. Post-release studies are required to confirm whether fitness is compromised in hands-on rehabilitated rhino. Until then, we suggest to minimize anthropogenic exposure during rehabilitation in order to maximize welfare and retain crucial behaviors for post-release adaptation and survival.