SANTA CLARA RIVER : Bird Watchers Help Terns Nest in Peace

Armed with signs, two-way radios and portable fences, Ventura County bird-watchers are helping safeguard a small gray-and-white bird species that faces extinction.

The California least tern, listed as being at risk since 1970, nests along the California coastline between the months of May and August. Nesting sites in Ventura County include a section of the Santa Clara River estuary in Ventura, Point Mugu and Ormond Beach in Oxnard.

The birds lay their purple-and-brown speckled eggs near the water and must be protected from beach-goers, who could easily trample them, said Don Davis, vice president of the western Ventura County chapter of the Audubon Society.

The birds scrape a spot in the sand and lay their eggs, which are well camouflaged.

The birds are protected at their breeding grounds at Point Mugu because the Navy property is off-limits to most people. And the Ormond Beach nesting area, a favorite for off-road vehicles, has been partially sealed off and is patrolled by the Oxnard Police Department.

But at the Santa Clara River estuary, the terns nest in an increasingly popular area. So for the past five years, the Audubon Society--with help from the city of Ventura, the Ventura Port District, the state Fish and Game Commission and McGrath State Beach rangers--fences a 500-by-200-foot area of beach as a breeding ground from late April to late August.

The four-foot-high chain-link fence cuts the area off to foot traffic and is surrounded by signs informing people that it is a nesting area.

On weekends, about 45 Audubon Society members rotate shifts from noon until dark, answering questions and keeping people at a distance from the birds, who make a distinctive sound like a Kewpie doll squeaking, Davis said.

“People are understanding and cooperative,” said monitor Bobbe Dorsey of Ventura.

But unleashed dogs have to be chased away, she said.

Monitors carry two-way radios to notify rangers or police if they need help but have not had to use them, Dorsey said.

The fence also protects the terns from wild cats, foxes and weasels that live nearby.

The terns themselves handle threats from aerial predators.

When a sea gull flies over the nesting area, the colony of about 45 terns takes flight and harasses it.

“Terns are very agile and can fly loops around a poor old lumbering gull,” Davis said.

This season, the colony is larger than usual, in part because the Point Mugu nesting ground was washed out by a storm Memorial Day weekend.

It is now mating season for the gray-and-white birds, which are about nine inches long with a 20-inch wing span. In the birds’ mating ritual, the male first presents the female with a fish and bobs his head repeatedly. After they mate, the female lays one to four eggs within a couple of days. Incubation lasts 3 1/2 weeks with parents taking turns on the nest.

Within a day of breaking from the shell, the speckled chicks can scurry to hide under the short dune plants.

Both parents catch minnows and sticklebacks from nearby ponds or smelt from the ocean to feed their hungry brood.

As chicks grow feathers, the family leaves the nest to live by various ponds in the county, including those at golf courses.

In the fall, the terns fly south to winter in southern Baja California and Central America.

In 1989, about 1,233 pairs of least terns bred at 28 sites between San Diego and the San Francisco Bay Area, according to a field study by the state Department of Fish and Game.