Beachgoers are likely to notice fenced-in areas on Mandalay and Hollywood beaches in Oxnard.
Other beaches along the coast have fenced areas too.
California State Parks' environmental scientist Alexis Franges used binoculars to check on the birds. She said the the fenced areas are protecting endangered and threatened birds that nest right on the sand.
She took photographs of the Snowy Plover eggs, which look like sand-colored camouflage, making them difficult to see.
Environmentalists are also protecting California Least Terns nesting near the mouth of the Channel Islands Harbor.
They hope people will obey the signs through September when the nesting season usually ends.