TORONTO -- Michael Buble has a group of Australian gorillas feeling some type of way.

The Canadian crooner recently visited a Melbourne-area zoo to sing for a trio of male gorillas that exhibited calm behaviour after staff played the apes his Christmas album.

“When we play Michael Buble’s CDs, the boys will instantly start ‘pleasure grumbling’ and sit nice and calm and relaxed,” said Ben Gulli, a gorilla keeper at the Werribee Open Range Zoo.

The singer’s recent live performance of songs off his album “Christmas” was captured on camera by the Werribee Open Range Zoo.

“I’ll be home for summer, you can plan on me,” Buble sang, altering the lyrics of “I’ll Be Home for Christmas” to suit the Australian summer. “Please have sun and ape-y fun and presents, lots of presents, under the tree.”

Zoo staff guess there’s something about Buble’s deep baritone singing voice that calms the animals, which have started to hum while they eat.

“Our theory is it’s the beautiful low tones that he sings with (that) kind of mimics their ‘pleasure grumble,’” said Gulli. They’ve even been shown to hum little food songs when they eat. We think he must really resonate with that sound.”