Vision-impaired snow leopard cubs teach us how to see a better world

Posted by: Dr. Deborah B. Jensen, President and CEO


Mother Nature isn’t always kind. Just as some human babies are born with congenital conditions that throw their parents for a loop, leading them to make extraordinary commitments to their children’s special needs, the same can be true for animals.

As you recall from last year’s stories, our endangered snow leopard cubs, Asha and Shanti, now 15 months old, were born with multiple ocular coloboma. This relatively rare congenital eye anomaly affects both human and non-human animals including Bengal tigers, Florida panthers, snow leopards, horses, and certain breeds of domestic cats and dogs. In Greek, coloboma means “unfinished.” The eye stops growing before it is fully developed. Ultimately, Asha and Shanti would develop functional vision only in their left eyes.

Many of you wrote to us with outpourings of encouragement and hope for the cubs’ struggle, and for the expert staff caring for them. So I’d like to update you since they took their first baby steps in their exhibit a year ago.

See for yourself! A picture is worth a thousand words. Asha and Shanti have been developing into thriving, rambunctious creatures that embrace each day with enviable gusto.

From 10 weeks old to… 

Leaping Leopards!! Several months later, a cub shows off her air-diving prowess just like her wild counterparts, which maneuver steep, rocky mountainsides as they travel to hunt prey.  Photos: (Top) Ryan Hawk/Woodland Park Zoo; (Bottom) Ryan Harveland, WPZ member and avid photographer.

In the wild, cubs with serious vision impairment might not survive very long. But at the zoo, because of excellent care from mom Helen, and our dedicated animal management and veterinary teams, these spots of beauty are leading vibrant, high-quality lives. They’ve mastered motor and navigational skills. But for a few small differences, which we monitor closely, they explore, play, leap and rough-and-tumble with the delight and earnestness that any fully sighted snow leopard cubs would. Helen has taught the cubs well how to bask in their glorious snow leopardness.

Let the chase begin! Photo: Annette Fallin, WPZ member and avid photographer

The cubs learn all they can from mom, who has shown both skill, patience and diligence in helping Asha and Shanti develop. Photo by Ryan Hawk/Woodland Park Zoo.

In turn, they are teaching all of us—zoo professionals, zoo members and our many guests—how to envision a better world for animals and people.

Much like the snow leopard’s elusiveness, the etiology of coloboma remains puzzling. Scientists have more research to do to determine whether it is genetics or other factors, including environmental ones such as diet, that lead this eye malformation to develop in the embryo. Currently there is no cure for coloboma, but with continued research and medical collaborations, one may be possible. 

There is heartening news. Using blood samples collected from Asha and Shanti during veterinary exams, researchers at Cornell University and the University of Illinois, who specialize in veterinary ophthalmology, molecular diagnostics, and DNA studies on inherited diseases, have agreed to collaborate with their time and technology to pilot a research study using Asha’s and Shanti’s DNA. They will look for clues to a possible genetic cause of coloboma. If a genetic marker is found, a screening test could be used to evaluate those snow leopards with a high risk of passing on ocular coloboma to their offspring. Adding to the research others have done on this condition will help zoo and conservation efforts to help this species have a healthier, sustainable future. 

By six months, the cubs’ play skills, such as what we human animals might call “hide and seek,” were in full swing. Photo by Dennis Dow/Woodland Park Zoo

As with any endangered species, continuing population decline puts pressure on genetic diversity. Native to the remote, mountainous regions of Central Asia, the wild snow leopard population has diminished precipitously in the last several decades. 

Scientists and zoo veterinarians know that snow leopards are more susceptible to certain health problems, such as pneumonia, hip dysplasia and papillomaviruses among others, than other large cats. Coloboma has been documented in captive snow leopards but not yet in their wild counterparts, as we are just beginning to gain deeper glimpses into the hidden lives of these “mountain ghosts.” Only recently, the first video coverage of snow leopard cubs in a den in the wild was achieved by the Snow Leopard Trust, one of our zoo’s Partners for Wildlife.

What we learn from the ocular coloboma pilot study will contribute to improving the health of the captive population and add to other research being done on this species’ health as a whole. As has long been the case with zoo animals, we anticipate these combined efforts will produce insights and knowledge useful in the conservation of wild populations.

Helen, above, and father Tom (not pictured) did sire two healthy cubs, Gobi and Batu, in May of 2009. Batu, now at Assiniboine Zoo in Manitoba, Canada, gave birth in July to her own cubs. They passed their health tests with flying colors. Photo by Ryan Hawk/Woodland Park Zoo.

Several weeks ago, after close observations to evaluate some discharge in Asha’s and Shanti’s underdeveloped right eyes, Dr. Tom Sullivan, a veterinary ophthalmologist volunteering his expertise to the cubs’ eye care, and Dr. Darin Collins, Director of WPZ Animal Health, decided to remove the deformed eye to prevent infection and future complications. Since returning to their mom and exhibit, the girls are back to their antics and continue to excel.

What’s in store for their future? In the wild, juvenile snow leopards and their mothers typically part at about 18 months of age. Asha and Shanti have been recommended to move to Big Bear Alpine Zoo, in California, by the Snow Leopard Species Survival Plan (SSP), a cooperative animal management and breeding program for populations in North American zoos and aquariums. Feisty and playful, there the sisters will continue to thrive together and receive specialized eye care. Although they will not be bred, they will continue to be outstanding conservation ambassadors. 

Showing some “luv” for mom. Photo by Jeremy Dwyer-Lindgren/Woodland Park Zoo.

Looking into Asha’s and Shanti’s eyes, one’s initial sadness is quickly replaced with wonder and amazement at their zest for life. Every day is a new adventure on their journey to inspire us to learn, care and act to save their counterparts in the wild.  Be sure to visit them here at Woodland Park Zoo before they embark on their California trek this fall.  

Until then, I leave you with a thought often attributed to Helen Keller. While any loss of sight may be challenging, it is far worse to have sight but no vision. See these snow leopard cubs and I guarantee you’ll see the world in a whole new way.

Photo by Annette Fallin, WPZ member and avid photographer.