Cheyenne Mountain Zoo (CMZoo) and Toronto Zoo are still emotionally processing the tragic loss of 2-year-old female Amur tiger, Mila. Mila [mee-lah] passed away on Fri., Aug. 25, at Cheyenne Mountain Zoo.
Mila moved to CMZoo in March 2023, after showing signs she was ready for her own space, away from her mother at Toronto Zoo. She came to CMZoo on a future breeding recommendation. Because Amur tigers are solitary animals, she never met CMZoo’s male tiger, Chewy.
“She was making such great progress with us,” said Rebecca Zwicker, animal care manager in Asian Highlands at CMZoo. “She was a feisty and intelligent tiger, and the team had been patiently and consistently training with her to help her settle in and feel comfortable in indoor and outdoor spaces behind the scenes. She was getting so close to being out where guests could see her. We were excited to introduce her to our community and for people to fall in love with her here, just as they had in Toronto.”
One thing delaying Mila’s introduction to the CMZoo community was the need to address a recently discovered and severe dental issue. This was not just a cavity; and it could not be left untreated, as it was advancing to her sinuses. Left untreated, infections like this can be fatal for animals.
The team had been working with Mila on several important husbandry behaviors that would allow her to live a life with lots of choice, autonomy and care at the Zoo. She was focused on shifting to different areas comfortably and returning to keepers when called. Once they realized she needed surgery to treat her dental issue, they prioritized re-establishing voluntary injection training that the Toronto Zoo Wildlife Care staff had previously established.
Thanks to this training, on Friday, she voluntarily received the injection of initial anesthesia, then she jumped up on a bench where she began to lay down and peacefully let the anesthetic drugs take effect. Less than a minute after lying down, she slipped off of the waist-high bench, causing a fatal spinal injury. Given the short timeframe from her lying down to her slipping off, it was impossible from a human safety standpoint to stop her tragic fall.
“She could have slid off from that height a hundred times and landed in a variety of other positions and been unaffected,” said Dr. Eric Klaphake, CMZoo head veterinarian. “The team quickly entered her den when it was safe and diligently tried for 40 minutes to give her life-saving care.”
“These are impossible life-and-death decisions being made in real time by a team that has dedicated their life to the care of animals. Do you anesthetize her despite the risks and give her the dental care she needs? Once you see her slipping, you wonder if you can safely get in there to stop a 270-pound tiger from falling completely. How fast can you safely go in and provide rescue attempts?,” said Bob Chastain, CMZoo president and CEO. “You can plan and plan and things still go wrong. Our team delivered exactly the right amount of drugs to a very calm tiger who had trained for this moment. We have successfully anesthetized countless tigers in this same den, and have never experienced an accident like this. We never take decisions to anesthetize an animal for a procedure lightly, and this is a tragic example of why.”
While CMZoo and Toronto Zoo teams work through the loss, CMZoo is focused on preventing this freak accident from happening in the future. Mila is the second female Amur tiger to pass away at CMZoo in recent years. In 2021, Savelii passed away due to complications during recovery from this important artificial insemination procedure. Their deaths are unrelated, but the fragile state of their species is glaring. It was after this death that CMZoo made a long-term financial decision to support tigers in their natural habitat as well as in the Zoo.
“It is sobering to know that no matter how tragic these events are, that we are losing tigers in the wild every day as these animals, and many like them, struggle to survive in a world where there are so many people and so few wild places,” said Chastain. “And that despite the best professional care that we give these animals, accidents can happen and will happen as long as there is a critical need for conservationists to help highly endangered species survive in human care and in the wild.”
“Watching Mila transform from a playful and curious young cub to an independent and often feisty young adult was an incredible experience for me, the Zoo team and the Toronto community,” says Dolf DeJong, CEO, Toronto Zoo. “She will be deeply missed by all, and while we feel certain the connections she made with guests will stay with them for a lifetime and were an inspiration to get involved in the fight to save this endangered species in the wild, we are deeply saddened by her loss”.
Amur tigers are critically endangered in the wild with only around 500 individual tigers roaming their native habitats. The numbers in human care, at zoos and aquariums accredited by the Association of Zoos and Aquariums (AZA) in the U.S. and Canada, hover near just 100 individuals.
“We feel a huge responsibility for all of the animals in our care, and we especially feel for Mila, her current and past caretakers and the people in Toronto who loved her from her birth as the only survivor in her litter,” said Chastain. “Not only was she an internationally beloved individual who defied the odds as a cub and survived to adulthood, but she was here on a mission to save her own species.”