Last Halloween, visitors to the Zoo were in for a rare treat—the chance to witness the first hippo birth at the Zoo in 26 years. Baby Rosie’s arrival was greeted by applause and gasps of awe from the nearly 100 people—a mix of Zoo staff, volunteers, and guests—who had gathered around the hippo exhibit. She became a media sensation—not just because of her adorableness—but because her birth was a surprise. Her mother, Mara, had been on birth control.
These surprises are the exception to the rule. Most zoo births are the result of careful planning and premeditation. And while baby animals are an indisputable draw, zoos do not plan births to boost attendance, but rather to save species.
When females are not recommended to breed, they are either housed apart from males or put on birth control. A number of products have been developed specifically for use in animals, including MGA (melengestrol acetate) implants and Depo-Provera (an injectable contraceptive).
The science of contraception is not always exact when it comes to exotic animals. Mara was given a Depo-Provera injection every six weeks as recommended. Though hippo Rosie’s birth was unplanned, it was a pleasant surprise. “Demographically, it’s good because zoos aren’t breeding hippos right now so there’s a decline in the population,” says Jeff Holland, Curator of Mammals. The birth is also a boon to the gene pool—Rosie’s dad, Adhama, is the only surviving offspring of former L.A. Zoo resident Otis. Wild populations are also decreasing; the species is classified as “vulnerable” by the IUCN (International Union for the Conservation of Nature, the organization that assesses the conservation status of animal populations globally).
Six months after her surprise birth, Rosie is healthy and growing steadily. She’s still nursing but will often test the solid food put out for her parents. Inseparable from mom Mara in her first weeks, nowadays she also spends time hanging out with Adhama or exploring the enclosure on her own.
Once fully grown, Rosie will likely be transferred to another zoo and eventually paired with a suitable mate. Today, unaware of her future role in safeguarding her species’ future, she is content to snuggle with mom and dad—and bask in the attention of her adoring fans.