Nursing behaviours of black rhinoceros Diceros bicornis in a zoological park: a case report

Abstract

The black rhinoceros Diceros bicornis is a Critically Endangered species for which detailed information on mother–immature offspring relationships in the wild is scarce. Furthermore, no longitudinal data on development of immatures are available, even in captivity. At Hiroshima City Asa Zoological Park, Japan, nursing behaviours of one adult female rhinoceros were quantitatively examined with her fourth offspring (a female) over the entire 25-month period of lactation, and with her fifth calf (also female) over the first 21 months. The mother accepted over half of all suckling attempts by the calves and actively terminated fewer suckling bouts than the calves did during most of the lactation period. The average durations of mother- and offspring-terminated suckling bouts were similar, and bout durations increased with offspring age. These findings suggest considerable tolerance of offspring’s nursing needs in female black rhinoceros.