The tree reportedly had dry rot.
Volunteers from the Audubon Society and the Oakland Zoo responded in minutes to help rescue some 20 birds and their babies.
"We have Oakland Public Works doing an amazing job, just patiently going through, branch by branch, just cutting very carefully to not injure any of the animals as we're rescuing them," Oakland Animal Services' Denise Bongiovanni said.
At least four birds were killed, three of them nestlings.
The injured birds were taken to the International Bird Rescue where they'll be nursed back to health.