Bullfrogs aren't native to California
at all. They are native to Eastern part
of the USA. They crossed the Rockies
due to frog farming, escaped and are all
over the place now.
Biologists do clear them out from time to
time in areas where native frogs are in danger
of being snarfed up by the bullfrogs.

I'm not sure what frogs the French eat...
off to google!
Okay, looks like the native frog the French
eat is called Rana esculenta - common european frog.
They seem to import a lot of these frogs from Asian countries to eat,
Kaloula pulchra. Otherwise known as Asian Bullfrog, so much so that
their native countries are in danger of being wiped out of these frogs
and the insect problem is climbing because of their absence.

Our north american bullfrog is Rana catesbeiana.

k :-)