In the corner of his new pool in the San Francisco Zoo, Henry the blind sea lion was enthusiastically swimming in circles.
A steady stream of water poured over his head as keepers refilled the pool’s water. Occasionally, he bumped into the wall, but then resumed his whirling laps.
A short distance away, a huskier and older sea lion named Silent Knight sat stoically in stark contrast to his energetic roommate. “They’ve actually gotten to the point in the last month where they use every aspect of this pool,” said keeper Debra Marrin.
The two sea lions moved to the zoo last month, after they were nursed back to the health at the Marin Mammal Center. Silent Knight had been shot in the face and blinded by an unknown assailant. Henry came into the center blind after suffering some unknown trauma.
But the addition of the blind sea lions has presented a challenge to keepers who have to train the animals to accept commands, which are necessary for things like applying medical treatment.
Marrin waves a yellow-tipped baton near Silent Knight, gently touching him on the nose to position him. A steady flow of fish serve as the reward. The baton is affixed with bells to help the sea lion understand where Marrin is guiding him.
“We’ve attached sound to the target so Silent Knight has a bell and he knows that’s his sound,” said Marrin.” “Henry has a caster of beads that kind of sounds like a maraca.”
Marrin developed the training by visiting keepers at the Marine Mammal Center who originally treated Silent Knight. She also got some tips from keepers at the zoo who are working with a gray seal that is losing his sight. “To work with two animals who weren’t trained before they were blind, that came in from the wild, we did just have to customize a plan just for them,” said Marrin.
Marrin said the pair of sea lions was skittish after first moving into the new exhibit. But they’re slowly exploring their new digs and gaining confidence.
"It’s really challenging, but it’s really rewarding," said Marrin. "We have people come up every day here at the zoo and say 'Oh you guys are so wonderful, you gave them a home.'"
Before the zoo took them in, the pair of sea lions faced an uncertain future. Because of their disabilities, rescuers couldn’t release them into the wild. And without a venue willing to host them, they might have been euthanized.
Instead, their new home has become a popular zoo stop, where young visitors expertly cite Silent Knight’s tragic tale.
Oblivious to all this, Silent Knight pushed his nose along the ground until he came to the water’s edge. He shuffled his large body into the pool, swam around, and began wrestling with Henry.