But it's nearby human residents who say they'll be crowded out when some 45 acres of open space is fenced off for the project.
The zoo's master plan, approved by the City Council ten years ago, included the eventual expansion into Knowland Park, a scenic hiking spot with views of San Francisco Bay.
Opponents say the zoo has since added more and bigger buildings to its proposal.
The "California!" exhibit would include grizzly bear, mountain lion, jaguar, wolf, eagle and California condor along with native plant species.