The white rhino is facing a desperately uncertain future. Demand for its horn for use in traditional medicine is increasing which means that a white rhino is a valuable kill for poachers.
This exerts huge pressure on the dwindling population, which is classified as “Near Threatened” on the IUCN’s Red List. White rhinos in breeding centers play a key role, by serving as a safeguarded reservoir. However, these rhinos show a worrisome phenomenon–extremely low reproduction.
Unresolved reproductive failure in the white rhino
Breeding programs in zoos and conservation centers play a very important role in the protection of the white rhino. These captive populations serve as a reservoir, enabling reintroduction into the wild. Unfortunately, many females in zoos worldwide fail to reproduce and seem to show aberrant cycling, for reasons which are still unknown. Because of this alarming low birth rate, rhino managers predict a crisis in the coming years.
These problems are not seen in the wild but until more is known about the reproductive biology of these animals it will be difficult to work out what causes the reproductive problems in captivity and to find solutions. This means that our options for conservation management and breeding strategies will be severely limited.
Free-living white rhinos as a model
With this IBREAM-project, wildlife researcher Annemieke van der Goot intensively monitored reproductive physiology and hormone cycles in free-living, healthy and effectively-reproducing white rhino females. This gave us valuable data that we can compare with captive rhinos to try and find solutions to the mysterious breeding problems seen in captivity. These field studies were conducted in nature reserves in southern Africa, and samples were analyzed at the University of Pretoria.
Every day we went out to track one or more rhinos and collect fecal samples. We used advanced tracking strategies, such as VHF radio telemetry and ear-notch identification, to collect as many useful data as possible. Also, we studied potential influencing factors, to further increase the chance of finding correlations in different facets of reproductive performance. We chose for a non-invasive way to obtain reproductive hormone levels. This way, the animals were not be disturbed in their natural habitat. The information learned in this project will greatly help zoo- and conservation scientists develop more specific and effective management tools to protect this vulnerable species and to increase reproductive health both in the wild and in captivity.
This Ph.D. project was completed on 14 January 2015. For a summary of the most important findings and for a copy of the original thesis click here.