World’s Oldest African Penguin Fights Skin Cancer

Tess, a resident of the Pueblo Zoo, received radiation therapy and is doing well.   

At age 40, Tess is currently the world's oldest living African Penguin. The joy of growing old is accompanied by inevitable ailments in penguins, too—last month, Tess was diagnosed with skin cancer. Her vets at Colorado’s Pueblo Zoo realized they could treat the exotic bird, giving Tess another superlative: first African Penguin to undergo cancer treatment. 

Cancer among zoo animals isn’t rare, according to Matthew Johnston, an avian medicine specialist at the Veterinary Teaching Hospital at Colorado State University in Fort Collins. As zoos have learned to better understand and meet animals’ needs, the animals are living to be older. “As a result, they are living into geriatric years, so now keepers are treating things like dental problems, kidney failure and cancer,” Johnston says. In the wild, African Penguins live for around 20 years, but that's greatly extended in captivity—the oldest recorded African Penguin lived to be 42. 

Tess’ cancer, though, isn’t common. Her keepers spotted a mass and suspected skin cancer when some wounds around her eyes weren’t healing quickly. The cancer was diagnosable thanks to its location, on Tess’ face—anywhere else, it would be hidden by feathers. Skin cancer is rare in penguins, Johnston said, and is even more mysterious in Tess because she lives indoors where she isn’t exposed to harmful ultraviolet light. The reason cancers like this occur is “the ten million dollar question,” Johnston said—no one really knows. 

“If you didn’t know her, you would never guess she’s as old as she is,” says Dr. Kathy Wolyn, Pueblo Zoo veterinarian in a press release. “That’s why we wanted to pursue further treatment for her tumor.”

Tess never had any offspring, and is now past reproductive age. But Tess is important for other reasons; she’s a key member of her penguin community, and of the Pueblo Zoo. “She may not be the dominant female, but she is a part of the flock and she deserves care,” Johnston said. Thanks to her age, she is a veritable zoo celebrity, Johnston added, and people who come to see Tess also learn about the plight of the African Penguin, an endangered species whose population has dropped 80 percent in the past 50 years. Conservation organization BirdLife International estimates that there are only 26,000 breeding pairs of African Penguins left in the wild.

Once Tess’s keepers spotted the mass, her vets surgically removed it and tested it for cancer. Analysis determined it was cancerous—a soft tissue sarcoma that is different from the forms of skin cancer found most often in humans. To treat it, in early December Johnston and his team at Colorado State University administered a relatively small dose of radiation via electronic brachytherapy, which allows technicians to target a small area. Tess’ keepers haven’t seen any side effects, like burns or ulcers in her mouth or around her eyes, and more than two weeks after the procedure, they are unlikely to appear. 

Due to the unprecedented nature of the case, Johnston gave Tess a relatively low dose of radiation. But even though he wasn’t following a scripted model for how to treat Tess, Johnston wasn’t totally winging it—veterinarians are trained in comparative medicine. “Veterinarians learn cutting edge medicine in dogs, cats, horses and cows,” he says. “We are constantly taking what we know from those species and adapting it to fit other species.” 

Veterinarians treat exotic birds by adapting what they’ve learned treating chickens. For example, Johnston knows birds are more resistant to radiation than mammals, so he’ll be tracking Tess closely to see how the sarcoma responds. If the cancer persists, she’ll receive another radiation dose in a few weeks. But for the moment she is doing well; after her two-week quarantine with her 33-year-old mate Mongo—standard for any animal that leaves an exhibit—Tess is back with her flock and on display. Her keepers hope she'll make it another few years, perhaps to claim the record for oldest African Penguin, ever. 

Johnston says he and his team were excited and to treat such a rare and endangered bird. Some conservationists fear the species will become extinct in the next few decades, thanks to sprawling commercial fisheries that affect the penguins’ prey. As a result, concerted efforts in zoos and designated breeding programs like the Southern African Foundation for the Conservation of Costal Birds hope to maintain a viable population to be reintroduced to the wild when conditions are more favorable—meaning if fish populations recover. Similar efforts with species like the black-footed ferret and the whooping crane have been moderately successful, so there’s a glimmer of hope for the African Penguin.  

“My goal goes beyond helping Tess—I want to make a difference,” Johnston said. “Awareness can lead a lot of people to action.”