Tasul, a polar bear known for her easygoing personality and groundbreaking contributions to conservation science, was humanely euthanized today to prevent suffering due to an aggressive cancer.
A couple weeks shy of her 32nd birthday, Tasul was the third-oldest polar bear in any North American zoo or aquarium, and one of the oldest on the planet. In the Arctic, polar bears seldom live past the age of 18, though wildlife biologists have documented two that lived to be 32.
During an ultrasound last week, zoo veterinarians discovered a mass on Tasul’s right ovary, and — after a biopsy revealed it to be cancerous — surgery was scheduled this morning to remove the mass and determine whether it had spread. One of DoveLewis Emergency Animal Hospital’s board-certified surgeons Dr. Ashley Magee had come to the zoo to perform the surgery. During surgery, however, it became clear the cancer had spread extensively and, to prevent her from suffering, animal-care staff made the difficult decision to euthanize.
“We know many zoo visitors are grieving along with us right now,” said Nicole Nicassio-Hiskey, the zoo’s senior marine life keeper, who knew the bear for more than 15 years. “Tasul touched a lot of people’s hearts, and she was such a great bear. She helped raise awareness about what’s happening to polar bears in the Arctic, and she helped the scientists who are studying what’s happening there. Wild polar bears are in trouble, and their future depends on all of us working together to combat climate change.”
“Tasul’s willingness to build a relationship with her keepers and to participate in training contributed so much to wild polar bears,” said keeper Amy Hash. “I want that to be her legacy. She’s contributed so much to her species.”
In 2011, Tasul became the first polar bear in the world to voluntarily give blood — a significant advance that improves animal welfare, especially during veterinary treatment. After reading about this milestone in the news, Dr. Karyn Rode, a scientist with the U.S. Geological Survey’s Polar Bear Team, contacted the zoo for assistance with the USGS’s Changing Arctic Ecosystems research.
Tasul helped Rode research how climate change is affecting the diets of wild polar bears. She also helped the USGS by wearing a high-tech collar to track her movements in order to learn more from collars deployed on polar bears in the Arctic. Polar bears are extremely difficult to observe in the wild, and Tasul’s data is helping researchers develop methods to remotely investigate how these predators are responding to the retreat of sea ice.
“This team of keepers truly revolutionized the way we care for polar bears in zoos, and Tasul was a shining example of that,” Cutting said. “When I first met Tasul 14 years ago, she could be nervous and apprehensive. It has truly been a privilege for me to watch her keepers build her trust and encourage her to express herself over the years. She evolved into a playful, confident bear, who was clearly ready to meet any challenge.”
Tasul was born Dec. 1, 1984, at the Riverbanks Zoo in Columbia, S.C. and arrived in Portland in 1986. She was popular with zoo visitors and staff — forming especially strong bonds with keepers.
In 2012, Tasul was included in an Oregonian article about elderly Oregon Zoo inhabitants that highlighted ways keepers and veterinary staff care for animals approaching the end of life. Zoo staff had been monitoring her closely and treating her for age-related ailments such as arthritis.
Keepers are disappointed that Tasul will not have the chance to serve as a friend and mentor to the 1-year-old Nora, who arrived here from the Columbus Zoo this fall. While the two bears had met, they had yet to become comfortable together.
“One of the reasons Nora came here was to meet another bear,” said curator Amy Cutting, who oversees the Oregon Zoo’s marine life area. “It’s beneficial for a young bear that was hand-raised to have a mentor bear as soon as possible, so we’re in touch with the Species Survival Plan about what is best for Nora at this time.”
Until a companion for Nora is found, Cutting said, the Oregon Zoo is fully prepared to provide care for her with enrichment, positive-reinforcement training and opportunities to participate in conservation science.
“We regularly get inquiries from other zoos about how to approach management and training with polar bears,” Cutting added. “We have a learned a ton from other talented teams out there that are also pushing the boundaries and developing strategies to continually improve polar bear welfare. It is an exciting time with polar bear management and conservation science and I believe that Tasul and this team have inspired an entire generation of polar bear managers.”
Climate science data shows that global warming is melting the Arctic sea ice polar bears call home, and with it, access to the food and shelter necessary for the species’ survival. The polar bear is designated as threatened under the U.S. Endangered Species Act, and the World Conservation Union’s Species Survival Commission has designated the species as facing a high risk of global extinction. If current climate trends are left unchecked, scientists predict the death of up to two-thirds of all wild polar bears by 2050.
People can help protect polar bears and other threatened wildlife through Small Actions, an easy-to-use online tool launched by the Oregon Zoo that empowers everyone to become a wildlife defender: oregonzoo.org/help-polar-bears.