Officials at the San Diego Zoo have welcomed the birth of an endangered baby southern white rhino.
The yet to be named male calf was born Sunday.
Zoo scientist Christopher Tubb said the birth is something of a breakthrough, as the zoo has had difficulty breeding the rhinos. He suspects chemicals in the rhino's food may have been the problem.
"So we suspect that these chemicals that are naturally produced by certain plants - called phytoestrogens - are playing a role in the low fertility of Southern White Rhinos," Tubb explained. "So two years ago, we altered their diet to reduce the amount of phytoestrogens that we were feeding them. About a year or so after that, we started to see some real interesting things in the herd, in terms of their reproductive behavior, and one of those was Holly's pregnancy, which we had not seen with her for 10 years."
Tubb says the new diet could serve as the link needed to improving the population of Southern white rhinos outside of Africa.