Monarchs Migrating Earlier Than Usual

El Nino is apparently bringing more than just weird weather and talkative meteorologists to Southern California.

The much-hyped meteorological condition also seems to have coaxed the largest and earliest migration of monarch butterflies ever to their California winter nesting grounds.

Tens of thousands of monarch butterflies are flitting about at more than 300 nesting sites in Ventura County and elsewhere in the state weeks earlier than normal.

“I’ve been working with monarchs for 10 years now and I’ve never seen anything like it,” said David Marriott, executive director of the nonprofit Monarch Program in Encinitas, Calif. “There are tens of thousands of butterflies that have already reached the San Francisco Bay Area by the first week of October and that’s very unusual. . . . It’s possible the weather conditions of El Nino are affecting the monarch populations this year.”

The distinctive orange and black butterflies have begun to arrive in coastal parks near the Ventura-Los Angeles County line as well, a phenomenon that doesn’t usually occur until the beginning of November, said Christina Craig, a ranger at Point Mugu State Park and Leo Carillo State Beach.

“We are seeing great numbers of them, especially in Sycamore Canyon Campground and the eucalyptus trees by Leo Carillo State Beach,” she said. “We generally don’t see them in these numbers.”

About 800 monarch butterflies are expected at Leo Carillo this winter, Marriott said.

But that figure is dwarfed by the estimated 10,000 butterflies that are expected to hang in huge clusters from the branches of a grove of eucalyptus trees in a ravine in Ventura’s Camino Real Park around Thanksgiving, when the monarch population peaks, Marriott said.

On Friday, stately monarchs could already be seen flitting through the quiet sunlit dell, with only the tapping of a nearby woodpecker breaking the silence.

“We’ve seen quite a few,” said Kathryn Babcock, whose backyard on Dean Drive overlooks the ravine. “Usually it’s November, later in the year. . . . They are one of the delights of living here because they swarm and at night you can see them hanging from the trees like grapes.”

The migration of the fragile monarchs, which can journey hundreds of miles along the West Coast, is considered one of nature’s great annual spectacles.

It is all the more amazing because unlike other migratory creatures, the tiny monarchs live only a matter of months. Those heading south today have never seen the winter roosts they’re headed for.

At two sites in California, Pismo Beach and Santa Cruz, an incredible 100,000 monarchs gather annually. But there are nesting sites in every county from Sonoma County south.

Weather conditions linked to El Nino in both Northern and Southern California have conspired to produce the same effect: more butterflies, Marriott said.

Northern California’s monarchs hail from the Pacific Northwest, which has seen an unusually wet and cool summer believed caused in part by El Nino.

Coastal sections of Washington and Oregon have seen rainfall more than 11 inches above average and temperatures three to five degrees below normal this summer and fall, said meteorologist Wes Etheridge of WeatherData Inc., a private company that provides weather forecasts for The Times.

That’s led to more and larger milkweed plants--the butterfly’s only source of sustenance--and a subsequent monarch population explosion. In addition, the cooler temperatures are prompting the monarchs to leave early.

“We don’t know if it’s a coincidence that the high population is occurring this year because of El Nino or the weather conditions of El Nino are affecting high populations,” he said. “In previous El Nino years, monarch populations have been high.”

Still, those who welcome the colorful winter companions are pleased that El Nino may have brought something positive to the region, in which the monarch population had lagged in recent years.

“I’m delighted to have monarchs again,” said retiree Barbara Born, who along with El Camino Real’s monarchs has also returned south to her home adjacent to the ravine after spending the summer in Washington’s San Juan Islands. “Years ago . . . the sky would be full of them.”