Giraffe usually give birth to a single calf throughout the year, although some locations report that conceptions are more likely during the wet season (Shorrocks, 2016). Several mother‐calf pairs will gather to form a nursery group in which all calves and their mothers are all together (Foster & Dagg, 1972; Langman, 1977). In general, lactating females spend more time foraging or drinking than nonlactating females (Fischhoff et al., 2007; Hamel & Côté, 2008). Hence, sometimes females in a nursery group will leave their calf to go to feed or drink while one of the other mothers remains with the calves to guard those (Paquet & Brook, 2004). In cases where the number of females (usually one or two females) is less than the number of calves the group is called a “crèche” (Jarman & Jarman, 1973; Leuthold, 1977). In addition to calves, giraffe younger than 1.5 years may join these nursery groups, that is, a crèche or a nursery group (Langman, 1977). To date, there has been no systematic study to examine whether female ungulates equally share responsibility in nursery groups. In this study, we focused on revealing how the role of guardian is shared by giraffe mothers.
