Daytime mother-calf relationships in reticulated giraffes (Giraffa cameloparadalis reticulate) at the Kyoto City Zoo.

Abstract

The present study quantitatively assesses the relationships between a reticulated giraffe mother and her first- and second-born calves during the first 22 months of the older calf's and the first 12 months of the younger calf's life at the Kyoto City Zoo, Japan. The mother permitted her calves to suckle at over 70% of their suckling attempts in the first month after their births, and the calves ceased suckling spontaneously in 65 to 70% of the suckling bouts. From the second month on, she showed a clear tendency to reject the calves' suckling attempts and terminated almost all of their suckling bouts, which resulted in approximately 60 sec or less of suckling duration per bout. The frequency of proximity between the mother and her calves remained at 20 to 30% throughout the first year, with no apparent developmental changes being evident. The mother was mainly responsible for terminating proximity by walking away from her calves throughout their first year after birth, while both calves were mainly responsible for attempting proximity by approaching their mother after reaching 2 months of age. Our study also showed that the giraffe mother became pregnant again while nursing her calves and ceased lactation (i.e., weaned the calves) before the fetus's growth started accelerating.