The California least tern (Sterna antillarum browni) nests in colonies by the San Diego river. They used to flourish from Moss Landing, Monterey County, California to San Jose del Cabo, southern Baja California, Mexico.
In the 19th and early 20th century terns were affected by the millinary trade which collected feathers for women's hats. Colonies on the east coast suffered the most.
The Migratory Bird Treaty Act of 1916 ended the threat, but the least tern plummeted again decades later.
Coastal development and recreational pressures destroyed habitat, disturbed birds, and increased predation by introduced and native species. The construction of the Pacific Coast Highway brought these threats to much of California's coast.
In recent years the bird has appeared on the endangered species list. Now in San Diego County, the population has increased to nearly 200 nests per acre.
A challenge to photograph, they fly in twists and wild turns on their way to snag a fish.
While sharp focus defies my camera, their antics entertain with feathery illusions.