Movement of Rehabilitated African Elephant Calves Following Soft Release Into a Wildlife Sanctuary

Abstract

The ability to locate essential resources is a critical step for wildlife translocated into novel environments. Understanding this process of exploration is highly desirable for management that seeks to resettle wildlife, particularly as translocation projects tend to be expensive and have a high potential for failure. African savannah elephants (Loxodonta africana) are very mobile and rely on large areas especially in arid environments, and are translocated for differing management and conservation objectives. Thus, research into how translocated elephants use the landscape when released may both guide elephant managers and be useful for translocations of other species that adjust their movement to social and ecological conditions. In this study, we investigated the movement of eight GPS tracked calves (translocated in three cohorts) following their soft release into a 107 km2 fenced wildlife sanctuary in northern Kenya and compared their movement with that of five tracked wild elephants in the sanctuary. We describe their exploration of the sanctuary, discovery of water points, and activity budgets during the first seven, 14, and 20 months after release. We explored how patterns are affected by time since release, ecological conditions, and social factors. We found that calves visited new areas of the sanctuary and water points during greener periods and earlier post-release. Social context was associated with exploration, with later release and association with wild elephants predictive of visits to new areas. Wild elephants tended to use a greater number of sites per 14-day period than the released calves. Activity budgets determined from hidden Markov models (including the states directed walk, encamped, and meandering) suggested that released calves differed from wild elephants. The first two cohorts of calves spent a significantly greater proportion of time in the directed walk state and a significantly lower proportion of time in the encamped state relative to the wild elephants. Our results represent a step forward in describing the movements of elephant orphan calves released to the wild following a period of profound social disruption when they lost their natal family and were rehabilitated with other orphan calves under human care. We discuss the implications of the elephant behavior we observed for improving release procedures and for defining success benchmarks for translocation projects.

Social integration of translocated wildlife: a case study of rehabilitated and released elephant calves in northern Kenya

“…Our preliminary findings contribute to conservation translocation knowledge by highlighting the importance of existing relationships to the transitional period post-release, and by documenting the length of time needed for signs of social integration and fission-fusion patterns to emerge. Analyses into the exploratory movement behavior of these calves indicates that social association with more knowledgeable released calves and with residents may be critical to facilitate knowledge of the landscape (Goldenberg et al 2021), which in turn may influence calf foraging efficiency and body condition. Detailed understanding of the development of such relationships as conducted here may illuminate the ways in which relationships among elephants may be leveraged to improve post-release outcomes.…”

“…If close proximity among released pairs post-release is a desired management outcome, e.g., to facilitate predation avoidance or knowledge exchange about the new environment (Poirier and Festa-Bianchet 2018;Goldenberg et al 2021), information about existing relationships can be leveraged to select release cohorts, or to facilitate interactions among release cohorts. It is possible that Baawa, in the third release cohort, may have facilitated interactions among the second and third release cohorts as a result of his strong existing relationship with Pokot, a similar aged male in the previous release cohort.…”

“…Facilitating interactions of recently released orphans with orphans that have had time to accrue knowledge of the release site may be an important factor to consider as it may take time for orphans to integrate with wild residents (Figs. 7,8), and ecological knowledge gained from associations with other elephants is likely essential for avoiding predation and locating resources (Kuiper et al 2018;Goldenberg et al 2021). However, we note that these results should be interpreted with caution as the small sample size of individuals whose interactions were documented pre-release did not allow us to control for the effects of age and sex on pairwise interactions.…”

“…This may be relevant to released animals regardless of the social structure of the species of interest, as many types of social relationships (e.g., territorial, Shier and Swaisgood 2012; cooperative (Shier 2006) require investment to establish. Promoting integration of released individuals within release cohorts and with resident populations may be particularly important for long-lived species that invest heavily in social relationships (Cheyne 2009) that are known to be negatively affected by social disruption (Engh et al 2006;Foley et al 2008;Nunez et al 2015), or whose knowledge of the new landscape may be facilitated by social relationships (Goldenberg et al 2021). Such integration may be especially challenging in orphaning, rehabilitation and release contexts in which animals may have had reduced exposure to normal social development and mentorship, and/or have spent time under human care and consequently may be more disconnected from social behavior typical of their species.…”

The behaviour and fate of translocated bull African savanna elephants (Loxodonta africana) into a novel environment

“…Given the relatively few cases of well documented translocations of African elephants in East Africa and the scarcity of studies investigating the impacts on movements and social behaviour following release (Goldenberg et al, 2019; 2021), we aimed to address this information gap. A sample of bull African savannah elephants ( Loxodonta africana ) ( n = 5) were scheduled to be translocated by Kenya Wildlife Service from Northern Kenya to Tsavo West National Park, approximately 500 km apart by road.…”