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Cho Cho, the Oldest Siamang
Cho Cho, the Oldest Siamang

How does it feel to be the oldest siamang – probably – in North America?

Well, for Cho Cho, snuggled up with his companion Dudlee on a crisp fall morning at Point Defiance Zoo & Aquarium, it seemed pretty cozy.

This year Cho Cho is celebrating his 51st birthday – which makes him the oldest siamang on record in human care in the U.S., and possibly the world. But thanks to the exceptional care he gets from our keepers and veterinary team, Cho Cho’s age isn’t slowing him down much.

Siamang Cho Cho on ropes in habitat
Cho Cho high in the ropes in the Asian Forest Sanctuary.

“He’s in good shape,” said senior staff biologist Telena Welsh, gazing at Cho Cho all cuddled up with Dudlee in the heated hammock, with adoring visitors looking on.

“He is definitely set in his habits – he likes things to go his way,” adds Welsh. “But he’s still incredibly strong and clever. He often outsmarts keepers with enrichments, and is always observing everything around him.”

Cho Cho and Dudlee the siamangs eating on the grass
Siamangs Cho Cho and Dudlee are great companions.

How to tell them apart visually? Dudlee has more gray around her muzzle, while Cho Cho has a

floppy throat sac and is a bit skinnier.

Siamangs are the largest species of gibbon in the primate family. They’re found in the wild living in the treetops of tropical rainforests in Sumatra and on the Malay Peninsula – which is why Cho Cho and Dudlee love the ropes, hammocks and perches in the Zoo’s Asian Forest Sanctuary habitats they rotate around with other animals. While Dudlee (who’s 23) loves to spin on the ropes, Cho Cho chills out more, Welsh says.

White cheeked gibbons Bobby and Sunisa.
White-cheeked gibbons Bobby and Sunisa.

But as well as seeing our siamangs, you can also hear them loud and clear, especially in the morning. Anyone who’s visited Point Defiance Park around 8am will have heard the unmistakable calls of our siamangs and white-cheeked gibbons: the higher-pitched, car-alarm-style “woop woop” of the gibbons and the lower-pitched siamang hoots.

“Each species has its own song, and each individual has their separate part,” explains Welsh. “In the wild they would probably use it to mark out territory and define family units.”

Here at the Zoo they’re also known to react vocally to nearby noises such as festivals or ambulances.

So how do you care for the country’s oldest known siamang?

Cho cho the siamang
Cho Cho.

“We watch him closely,” says Welsh. “He does get vitamins, and occasionally an anti-inflammatory that works like ibuprofen to relieve any age-related stiffness.”

Like Dudlee, Cho Cho also has almost no teeth left – a normal thing for siamangs this age – so Welsh and her staff either cook their food or slice it very thinly. And of course he gets regular senior wellness checkups from our veterinary team.

Mostly, though, Cho Cho is a healthy fellow who likes to groom his mate, sunbathe, and interact with the humans who care for him.

As Welsh calls him, the old siamang climbs over to the fence and puts a hand through, gently touching Welsh’s own in greeting – then lopes away after Dudlee.

-Rosemary Ponnekanti, PDZA