Last Friday, the National Zoo said goodbye to their oldest Sumatran tiger, Rokan—who was one of the longest-lived tigers in captivity.
“We knew he would get to the point when his quality of life was no longer medically manageable or acceptable,” wrote Dr. Katharine Hope, associate veterinarian at the zoo. “Input from the veterinary team, animal keepers and curators informs the careful decisions we must make about an elderly animal’s quality of life.”
Rokan, who was 20, lived five years longer than the average lifespan of a tiger in the wild. Sumatran tigers are considered critically endangered: Only about 4,000 of the animals remain in Asia's wilderness.
The tiger, who shared a name with the Rokan River in Sumatra, arrived at the Zoo in 1997 from the San Antonio Zoo, where he was born seven years earlier.
Aside from being very calm and unusually muscular for a Sumatran tiger (a species known for being rather sleek), he was an excellent breeder. He was the father of 10 surviving cubs (seven male and three females) born in four litters and managed by the Sumatran tiger Species Survival Plan, a program in which scientists select captive animals to breed based on their personality, health and genetic makeup.
Three of those litters paired Rokan with the Zoo's oldest female tiger, Soyono. Tigers are typically solitary in the wild, keepers said, but the pair had a close connection.
Rokan's health had begun to decline just less than two years ago, zoo officials say, when he began showing signs of lameness in one of his back legs. Though medication helped with pain, the lameness got worse, and officials found that the cause was actually a neuromuscular disorder, a product of a spinal cord disease. With medication, Rokan was able to retain his comfort and coordination until December 2009, when veterinarians decided he would be in too much pain to live much longer.
Though Rokan is gone, his legacy lives on through each of the 10 surviving cubs he produced—including four-year-old Guntur, who still calls the Zoo home.