The San Diego Zoo Safari Park welcomed a new addition on Saturday: a baby southern white rhino. The male rhino is now out and about in his habitat, staying close to his mother, Holly, and learning to balance on his big feet.
“Holly has not had a calf before, so genetically this calf is very valuable to the population,” said Christopher Tubbs, a scientist at the park.
Tubbs and other conservation researchers have been working for the past eight years to figure out why captive-born southern white rhinos give birth far less often than rhinos born in the wild. The 4-day-old rhino may prove that researchers have found the answer.
“We expect that these chemicals that are naturally produced by plants, called phytoestrogens, are playing a role in low fertility of southern white rhinos,” Tubbs said. “So two years ago, we altered their diet to reduce the amount of phytoestrogens that we’re feeding them. About a year or so after that, we started seeing some real interesting things in the herd in terms of reproductive behavior, and one of those was Holly’s pregnancy, which we hadn’t seen with her in 10 years.”
The 125-pound calf is expected to gain about 100 pounds each month for the first year, and he will weigh between 4,000 and 5,000 pounds by the time he’s full-grown at around age three.
“Scientifically, we think it’s been a little bit of a breakthrough for us, and gives us some ideas on how we can adjust diets here and in other institutions to hopefully increase fertility of the North American population as a whole,” Tubbs said.
Poaching has been on the rise in recent years, according to the San Diego Zoo. When the rhino fertility project began in 2007, 13 rhinos were poached that year. About 1,400 southern white rhinos were poached in South Africa in 2015. The animals are poached for their horns, which have become a status symbol in some cultures and are erroneously sought after for nonexistent medicinal qualities.
“Now, more than ever, we need a healthy population of rhinos outside of Africa,” Tubbs said.
With only 18,000 southern white rhinos left in the wild, the current rate of poaching could make them extinct in 15 years.
The new southern white rhino calf and his mom can be seen in their habitat at the San Diego Zoo Safari Park’s Africa Tram and Caravan safaris.