Oldest Eastern black rhino in U.S. dies at San Francisco zoo

SAN FRANCISCO (KTVU) - The oldest Eastern black rhino in the United States named "Elly" -- an 1,800-pound creature who had a penchant for watermelon and rolling around in in the mud -- has died at the San Francisco Zoo due to complications resulting from old age, officials said Tuesday. She was 46.

In December 2016, the oldest black rhino in Kenya died at age 42. A rhino's average life expectancy ranges from 35 to 50 years old. 

"Her long life speaks to the incredible care she received from animal staff, veterinarians and wellness experts at the zoo," zoo spokeswoman Rachel Eslick said in a statement. 

Elly arrived at the zoo as a juvenile on April 16, 1974. And over the last 43 years, she gave birth to 14 calves, and witnessed the births of 15 grand calves, 6 great-grand calves and even a great-great-grand calf. 

Her fertility and lineage were "tremendously important" to the growth and diversity of the captive population, Eslick said. That's because her species is critically endangered, with estimates of only between 5,042 and 5,455 left in the wild. 

"As one of our longest-standing residents, Elly was an outstanding animal ambassador for the endangered black rhino species, which faces continued risk from poaching, mainly for its horn," President of San Francisco Zoo & Gardens Tanya M. Peterson said in a statement.  "We are grateful to have celebrated many wonderful years with Elly, and she will be dearly missed by the Zoo team as well as millions of guests who connected with and cared for her." 

Elly was anesthetized on May 3 after an exploratory surgery on one of her legs showed that she was in a lot of pain, zoo officials said. The veterinarian team of experts decided her condition had deteriorated and she could no longer be treated while still maintaining a positive quality of life, officials said.

In lieu of flowers, the San Francisco Zoo asks that people visit the International Rhino Foundation to learn more about conservation efforts.