LAKE BUENA VISTA, Fla., Feb. 18, 2011 — At Disney’s Animal Kingdom, a very rare gorilla named Lilly is about to reach a monumental milestone – her first birthday. And while birthdays in the animal world are not typically marked on a calendar, Lilly’s first year has been historic.

Since she was born last Feb. 19, animal care experts around the globe have been keeping a watchful eye on Lilly’s development. Within weeks after her birth, Disney’s animal care team noticed she was different. She was much smaller than other gorillas her age and was not meeting typical behavioral milestones, such as grasping, rolling over and crawling. In addition, Lilly’s mother Kashata seemed to be holding the endangered western lowland gorilla longer than normal.

Puzzled, the team scoured medical journals and found no reports of similar cases. After consulting with external medical and pediatric experts, they conducted a series of tests to rule out possible causes, such as vitamin deficiencies, thyroid disorders and liver abnormalities. While the exact cause of her condition is still unknown, animal care experts believe she may have a developmental delay that affects her nerve and muscle cells. Without similar documented case studies in veterinary literature, the team realized that they had to pioneer new protocols in animal care and shifted their emphasis to treatment.

Each day, a team of animal keepers engages Lilly in what appears to be a form of play, but is actually a form of structured therapy. They encourage her to climb, roll over and grasp objects, including food and toys, all in an effort to strengthen her muscles and spark her curiosity. Since September, the team has noted a marked difference in the young primate. She now weighs 13 pounds – three pounds more than she did in November, and she appears much more active and social among her family grouping.

“We are committed to providing all our animals with the best care,” according to veterinarian Mark Stetter, D.V.M. “In Lilly’s case, we are encouraged by the progress in her stamina, strength and dexterity. But since there are no other documented cases like her, we are continuing to monitor her closely.”

Along the Pangani Forest Exploration Trail, Disney guests are captivated by Lilly. They are in awe of her toddler-like curiosity and marvel watching the tender interaction between her and the other gorillas on exhibit, including her 450-pound father, Gino.

For Disney’s Animal Programs team members, there’s no better way to celebrate a baby’s first birthday. “We are sharing the knowledge we’re learning from Lilly among professionals in the medical and zoological communities to help improve care for animals in zoological habitats and conservation efforts in the wild,” said Stetter.