SALINE COUNTY – Staff and patrons of Rolling Hills Zoo are mourning the loss of a Southern White Rhinoceros.

Milly was euthanized Wednesday morning due to declining health and her advanced age, according to a Rolling Hills Zoo media release.

In captivity, biologists estimate a rhino’s lifespan at about 40 years. Zoo officials say Milly was between 46 and 51-years-old.

“We have been caring for Milly in her advanced age, trying to make her as comfortable as possible, said Zoo Curator Brenda Gunder.

“She was finding it extremely difficult to stand up for long periods of time and it became apparent that her quality of life was deteriorating.”

Milly was born in South Africa. She arrived at the Rolling Hills Zoo in 1996 as part of the White Rhinoceros Species Survival Plan. Milly and Wagasa were among the first animals at the zoo, according to the press release.

“Milly seemed to always look out for her friend Wagasa by keeping the males in line,” said head keeper Vickie Musselman. “In turn, Wagasa would call to Milly if separated. Even though Milly is the smallest of all of our rhinos she has always been the little spit-fire when she felt that she needed to be and wasn’t shy about letting her keepers know.”

Approximately 20,000 white rhinos remain in the wild and they are considered a near-threatened species. “Unfortunately, over the years their population numbers have declined due to habitat loss and poaching. In the past four years over 1,000 annually have been killed, and within the next 20 years they could be extinct.”

Milly’s body was transported to Kansas State University for a necropsy.