Monarch butterflies on the rise after nearly vanishing
Western monarch butterflies, thought to be on the brink of extinction only two years ago, have rallied, with a new survey showing relatively high numbers this winter.
Over 330,000 of the graceful orange-andblack-winged insects were found in sites throughout Central California and the Bay Area in an annual Thanksgiving count organized by the Xerces Society, a conservation group that announced its findings Tuesday. It’s a big increase from the winter of 2020-21, when fewer than 2,000 monarchs were counted on the California coast. Last year, the number went up to almost 250,000.
“I think we can all celebrate,” said Emma Pelton, senior endangered species conservation biologist at Xerces Society. “It’s a sign we have a second chance.”
Conducted by 250 volunteers at 272 locations, the annual monarch count keeps tabs on a beloved butterfly that breeds in inland California and then travels to eastern and northern states in successive generations before migrating back to coastal areas from Mendocino County to the
Mexican border each winter. In the cold months, they spend most of their time in clusters high in eucalyptus trees and Monterey pines.
The cause of their recent rebound is still being studied, though Pelton said it’s difficult to pin down because of the “vast scale of the West and the vast scale of space and time that we deal with with this multigenerational species.”
The Xerces Society said that the recent storms may have taken a toll on butterflies, which were often seen blown down to the forest floor during surveys.
For those interested in seeing the monarchs, they should still be around for a few weeks at locations like Natural Bridges in Santa Cruz, Pacific Grove (Monterey County) and Pismo State Beach, said Isis Howard, endangered species conservation biologist at Xerces Society.
This year and last year’s numbers are still far below what they were in the 1980s, when millions of monarch butterflies flew to Central California. But one bright spot this year compared to last is that around 8,000 butterflies were counted in Bay Area locations, especially in Marin, Alameda
and Solano counties.
“We know we still have a long ways to go for recovery,” said Pelton. “We estimate we’re still down 90% from those historic norms.”
Monarch butterflies are mostly threatened by habitat loss and pesticide use. The state has invested over $1 million in monarch habitat restoration programs in Central California that scientists say could help their population recover.