At the San Francisco Zoo, an important birthday was celebrated this week. Elly the black rhino turned 45, and she celebrated with a "cake" of rolled oats and molasses. Her age is an estimate because she wasn't born in captivity, but she's lived at the zoo since 1974. Her keepers estimate her to be roughly 45. She is the oldest rhino in America, reports the Associated Press. In the wild, they live 16 to 20 years. 

Because of a surge in poaching in parts of Africa since the 1960s, the number of black rhinos out there has dwindled from 200,000 to 3,000-5,000, said zoo curator Jim Nappi, according to the Associated Press. However, Elly has helped in preserving this endangered species by giving birth to 14 calves throughout her long life, reports the BBC.

"All rhino species are in really poor shape. They're critically endangered as is the case with the black rhinos behind me here," says Nappi, according to KTVU. There are 60 black rhinos being cared for in zoos across America.

Elly weighs 2,000 pounds and rests on a comfy bed of hay to protect her fragile, aged bones. She shares a habitat with her grandson named Boone, and she's very well-loved among the rhinos and zookeepers of the San Francisco Zoo. "She's our little old lady that everyone pampers. She likes to interact with food. She's got a kind of independence to her, which is unique," says Nappi, according to Associated Press.