Rare Palos Verdes butterflies bred in captivity released into wildMarch 9, 2010 By Michael Finnegan in Biology / Plants & Animals
A rare blue butterfly took flight Saturday morning on a windswept bluff of the Palos Verdes Peninsula in California. Then another. And then another.
A cluster of conservationists watched in awe. In all, 80 endangered butterflies, each bred in captivity, ventured into the wild for the first time.
It was a big step toward saving the Palos Verdes blue butterfly from extinction. The peninsula had been its only home on Earth until 20th century development bulldozed its habitat.
"I'm just ecstatic to be here," biologist Jana Johnson told the gathering moments before the cobalt-blue butterflies were set free in a gully of San Pedro's Friendship Park.
"Take a look around," she said, nodding toward hillsides covered with homes overlooking the ocean and the Los Angeles basin. "It was wiped out by us. So it's our job to undo the past wrongs."
The Palos Verdes Blue is finicky, so it took conservationists a few years to prepare for its return to the park by landscaping slopes just to its liking. The thumbnail-size butterfly lays eggs on just two kinds of plants: locoweed and deerweed. Their leaves are the only things its larvae can eat after hatching.
The butterfly's life is short, typically five or 10 days. With so little time allotted for reproduction, butterfly keepers thought it best to release 60 males and 20 females.
"We wanted to have the maximum probability of getting mated," said Travis Longcore, science director of the Urban Wildlands Group.
The instant they were let out of their clear plastic cups, many of the butterflies opted first for food. They fluttered straight to the nearest sunflower shrub, uncurled their tiny snouts and started sucking up nectar from the yellow blossoms.
The butterfly's new Friendship Park habitat is its third in the wild since it was rescued from the brink of extinction in 1994. A sighting that year at a military fuel depot in San Pedro, Calif., marked the first time in more than a decade that anyone had spotted a Palos Verdes blue. Since then, thousands have been bred in captivity, many of them at Moorpark College in Ventura County, and released each year at this time.
"It was kind of like back from the dead -- resurrection," Longcore said.
The first habitat to be restored was at the fuel depot, where its estimated population has dipped to as low as 30, but risen to as high as 282.
The second habitat restored was a few miles away at the Chandler Preserve, where the Palos Verdes Blue was reintroduced last year. Biologists were pleased to discover in recent days that it has returned to the preserve this season on its own.
For the Friendship Park habitat, conservationists scattered the butterfly's favorite plants around eight acres. Multiple habitats supporting "a series of little populations" are the key to its survival, Johnson said.
Los Angeles County Supervisor Don Knabe, who released one of the butterflies into the L.A. County park, told the gathering of conservationists that he was pleased to hear there were now as many as 10,000, even if most are still in captivity.
"Those butterflies really know how to party," he said. "Two hundred to 10,000 -- man, they have a good time."
Still, biologists say it will take years to get enough Palos Verdes Blue surviving on their own in the wild to have them removed from the federal list of endangered species.
(c) 2010, Los Angeles Times.
Distributed by McClatchy-Tribune Information Services.
"Rare Palos Verdes butterflies bred in captivity released into wild" March 9, 2010 https://phys.org/news/2010-03-rare-palos-verdes-butterflies-bred.html