Parker, one of two endangered red pandas at the Birmingham Zoo in Alabama, died of unknown causes on Sunday.
The 4-year-old red panda was found dead in his enclosure with no obvious physical injuries or any indication of illness, the Birmingham Zoo said Monday. Results of Parker's necropsy are still pending, according to Dr. Stephanie McCain, Birmingham Zoo's director of animal health.
"We hope to know more information in the coming weeks," McCain said in a statement. "Parker’s passing is very heartbreaking. He was a great red panda and a favorite of many — he will be greatly missed by all of us.”
Red pandas are an endangered breed of mammals who have suffered from habitat loss and poaching, according to the Smithsonian National Zoo. Researchers estimate that their population has decreased by more than 40 percent over the last 20 years.
A red panda can live to be up to 23 years old, according to the Smithsonian.
The small, russet colored, animals are skilled climbers who spend their time in treetops eating bamboo, but they aren't closely related to giant pandas.
Parker was one of two red pandas at the Birmingham Zoo. The other, a 9-year-old female named Sorrel, is being closely monitored but showing no sign of illness, the zoo said.
Birmingham Zoo President and CEO Chris Pfefferkorn said in a statement that Parker's death was a "devastating loss" for all the staff, volunteers and visitors who loved him.
"He always received the best care and attention from our Animal Care staff, and he was quite adept at participating in husbandry training and learning new behaviors that greatly assisted with his care," Pfefferkorn said. "Parker holds a special place in our hearts, and he will be deeply missed.”