Not so solitary? White rhinos seek company when relaxed

Abstract

White rhinoceros (Ceratotherium simum simum) have been classified as “semi-social” as they often form groups or temporary aggregations of two to six individuals (Owen-Smith 1975; Patton et al. 2016; Pienaar 1994; Shrader and Owen-Smith 2002). Social behaviours such as grazing, and/or walking together and lying side by side, rubbing their head and body (sides) on another rhino and making panting contact calls, have been described in other studies (Owen-Smith 1975; Jenikejew et al. 2020). Playful behaviour such as horn wrestling has also been observed before in white rhinos (Owen-Smith 1975; Cinková and Bičík 2013).

Our field research in Botswana supports findings about the sociability of white rhinos and adds the observation of a calf suckling from a female that was not her biological mother, to the spectrum of social interactions between rhinos.

We observed one to three adult rhinos per day over a period of 60 days between March and May 2020. During the observation, we focused on one individual, hereafter called the “focal rhino”, and videorecorded it for 30 minutes. We identified the rhinos through their individual ear notches and observed them in semi-randomized order at different times of the day. For each observation, we noted the number of individuals in a group at the same location. There was potential for more than eight adults to meet in the reserve (the total numbers of individuals are withheld for security reasons). Furthermore, the rhinos were dehorned after 30 days, and we were able to monitor whether dehorning had an effect on the group sizes.