Release from captivity allows African savannah elephant movement patterns to converge with those of wild and rehabilitated conspecifics

Abstract

Rewilding captive animals is an important strategy for rehabilitating individuals and ecosystems. Comparing the behaviors of released animals to their wild counterparts enables the evaluation of their adaptive response to new environments, assuming that wild animals are better suited to natural conditions. We examined how movement patterns of captive African savannah elephants (Loxodonta africana) before and after soft release compared with movement patterns of other elephant groups, rehabilitated and wild elephants, in the western Okavango Delta, Botswana. We monitored 12 adult female elephants using GPS collars: six captive elephants, subjected to a three-year phased soft release, two elephants released more than a decade earlier and four wild elephants. We quantified 30-min diurnal and nocturnal distances, cumulative daily distances, daily displacement, and monthly home range sizes across seasonal flood cycles. We analyzed the effects of release, season, time of day, and elephant group on movement metrics, comparing captive elephants before and after release, and with rehabilitated and wild elephants. Before release, captive elephants moved longer diurnal and shorter nocturnal 30-min distances, covered longer cumulative daily distances, and occupied smaller home ranges. After release, these metrics shifted, reducing differences with rehabilitated and wild elephants, although captive elephant home ranges remained significantly smaller. This suggests that captive elephants changed their movement patterns post-release in response to environmental cues. However, even the movement patterns of rehabilitated elephants were not completely similar to those of wild elephants, likely due to sample size, individual variation, or effects of prior taming. These results highlight the critical importance of long-term monitoring of animals since the movement patterns of released animals may take several years to converge with those of wild counterparts.