Editor's note: Read Part 1 of Dr. Swaisgood's essay, about the dangers today's rhinos face.

The Zoological Society of San Diego takes the various threats to rhinos seriously. We participate in the American Zoo and Aquarium Association’s Species Survival Plans for three species, the Indian, black and white rhinoceroses. The goal of these programs is to establish sustainable captive populations to serve as a safeguard against extinction in the wild and, if necessary, to provide animals for release back to the wild after the threats have been removed. Our rhinos have flourished and we have produced more Indian and white rhino calves than any other institution.

At the San Diego Zoo’s center for Conservation and Research for Endangered Species (CRES) researchers have studied genetics, nutrition, disease, physiology, behavior, and ecology of rhinos. I’ve been involved in a black rhino translocation program in South Africa and Namibia for several years. The governments of these countries are engaged in a large-scale translocation program to re-populate southern Africa with these charismatic animals—that is, they capture them in reserves where there are surplus rhino and move them to areas where they are rare or locally extinct. The problem is, released black rhinos don’t always do so well and can become stressed, run through fences and injure themselves, or fight. Mortalities are unacceptably high. We’ve been working to try to remedy this situation. We’ve tried a number of different strategies to make these translocations more successful—one even involved carrying backpacks full of rhino dung out to “seed” areas with rhino scent in the hope of getting them to settle down in the right place, just next to the virtual scent territory we created. It worked!

In another program I’ve been involved in for a decade, we’ve been trying to solve the mystery of poor reproduction among female white rhinos born in captivity. The wild-caught females brought into zoos around the world bred well, at least when managed appropriately. But the daughters of these females have been notoriously difficult to breed. I’ve conducted some studies that ruled out most hypotheses (no, the older wild-caught females are not suppressing reproduction in the younger captive-born ones), but we still are in search of a definitive answer. It seems that something is happening during the development of female calves in captivity, since often the only thing different about the captive-born and wild-caught females is where they grew up. This insight has led me to pursue field studies in Africa, but, while providing more insights (and ticks and near-death experiences!), we still have not solved the problem. We are now embarking on new multi-disciplinary studies, hoping to nail this one down before we run out of time. Most of the wild-caught females are aging and beginning to die off, so we could watch the captive population go extinct if something isn’t done soon. And, with the possibility of political instability always lurking, we never know when the wild population may undergo yet another rapid decline if the anti-poaching programs aren’t maintained. If left unprotected, they can go fast—more than 95% of black rhinos were wiped out in a decade or so.

Responses[2]

Posted by Dr. Ronald Swaisgood on June 14, 2007 2:55:00 PM PDT #