Movement behaviour after birth demonstrates precocial abilities of African savannah elephant, Loxodonta africana, calves

Abstract

Living in groups has many benefits including predator protection and information sharing that can outweigh the associated costs. African savannah elephants live in a matriarchal fission–fusion social structure where groups merge or split depending on the relative costs of group living. However, elephants are also nonsynchronous breeders which may cause optimal movement patterns to differ between group members, particularly around parturition. Both the mother and the group must assess whether the benefits outweigh the costs of group cohesion. Understanding the impact of gestation, parturition and the presence of a newborn calf on the mother's movement patterns could provide key insights into the drivers of fission–fusion social dynamics. Here, we examined the relationship between reproductive state and movement using GPS tracking data collected during 23 parturitions from multiparous elephants (≥ second calving) and three from primiparous females. We analysed daily mean speed before, during and after parturition, and used a three-state hidden Markov model to determine whether parturition results in a distinctive change in speed. The results show that, although speed decreased on the estimated parturition date, parturition could only be detected in four of 23 multiparous parturition events when placed in the context of speed over a 2-month period. Furthermore, the speed on the day before and the day after parturition (i.e. first complete day of the calf's life) was not significantly different from the yearly mean. By contrast, a speed decrease was detected in the limited sample of primiparous females but was of short duration. Our results indicate that the precocial abilities of calves facilitate the maintenance of group cohesion within the matriarchal fission–fusion social structure of elephants. We speculate that, alongside cognitive development, elephants may have evolved a long gestation period to facilitate an advanced stage of fetal physical development. • We analysed the movement behaviour of parturient African savannah elephants. • Gestation, parturition and neonatal calves had little impact on mothers' movements. • We demonstrate the precocial abilities of elephant calves. • Movement after birth could be a significant advantage for a social species. • Extended gestation of elephants may have evolved for advanced fetal development.