Eastern black rhinoceros. Photo: May Woon, courtesy San Francisco Zoo.

Gene, a 41-year-old black rhinoceros, has died at the San Francisco Zoo.

According to a press release from the zoo, the rhino died Feb. 27 after a long illness including liver failure. Gene was known for his gentle and friendly nature, and was named after one of the zoo’s biggest benefactors:

Gene was the namesake of the late Eugene Friend, who served on Recreation and Park Commission for 24 years, 13 as president. Also a Benefactor of the Zoo, Mr. Friend and his continual generosity is permanently recognized at the Friend Family Entry Village, Dentzel Carousel and the children’s playground. “Elly,” the female black rhino that Gene shared the African exhibit with was named after Elinor Friend who showed her love for children by sponsoring visits for them to the San Francisco Zoo.

Born in Kenya, Gene arrived at the Zoo in 1978 at the age of seven. During his time here he sired five offspring, three of which are living at other American Zoo and Aquarium (AZA) accredited zoos. His animal keeper Julie McGilvray describes him as having a good disposition and being very friendly. “We nicknamed him Big Dog,” McGilvray explained, “because he loved to be rubbed, either by hand or with a scrub brush, and oftentimes he would lie down and absorb the soothing experience.”

A critically endangered species, black rhinoceroses are victims of illegal poaching for the two horns they carry on their skull. Although unconfirmed by scientific research, there is a belief in Chinese medicine that the ground-up horn helps in healing and increases sexual appetites. In reality, the rhino’s horns are used by them for food gathering to dig up and collect roots, twigs and branches.

One other black rhinoceros remains at the zoo, as well as a Sumatran rhinoceros.