There have only been a couple of monarchs spied inside the Pacific Grove Monarch Butterfly Sanctuary since the overwintering season officially began in October. Most days the tracker on the Pacific Grove Museum of Natural History website reads "0," based on reports from trained volunteers who regularly observe inside the sanctuary. Last year, the annual Thanksgiving week count was 642.
There's a worrisome reason for the abysmal showing, the Western monarch population as if this year's Thanksgiving week count for all overwintering sites along the coastline has dropped to below 1,800, according to the Xerces Society.
Two years ago the butterflies were just under 30,000 in number, and a couple of years before that, just shy of 100,000. That only about 1,800 could be found this year, with about 95 percent of the data in from the count that lasted Nov. 26-Dec. 6, is "really hard news to share," says Emma Pelton, senior conservation biologist for the Xerces Society. "We're all grappling with the fact that we continue to see the numbers spiraling."
The causes of the near extinction are still being studied, and there may not be just one reason why the butterflies are in such trouble.
"Monarch populations may be suffering from death by a thousand cuts," said Scott Black, executive director of the Xerces Society, in a press release issued Nov. 30, before the count was complete. "Destruction, degradation and neglect of overwintering sites, climate change and overuse of insecticides are likely contributing factors."
The impact of this year's wildfires could also be a contributing factor, but Pelton says even before the fires got underway in August, there were already signs that this year's population was going to be low. In addition to warmer temperatures in late summer and early fall, below average rainfall could limit the availability of nectar during migration and at overwintering sites.
Well-meaning people who want to help the monarchs by either planting non-native milkweed or raising monarchs in captivity for release could actually be harming the population, according to experts. The Xerces website cites research that indicates the practices may be increasing rates of disease among the species.
Pelton is not ready to give up on the Western monarchs, however. She says the insects are resilient and with help could one day make a comeback.
It's a glimmer of optimism shared by P.G. monarch activist Robert Pacelli, who says the monarchs have a way of moving around to places better suited to support them, and if just 10 survive and mate, it could lead to repopulation in the future.
He's continuing efforts to give monarchs more trees to cling to in the overwintering months, by raising more than 100 boxed trees that other residents have agreed to host in their yards to create "monarch islands" around P.G., particularly in areas where monarchs have historically overwintered in the past.
"Hope always springs eternal," Pacelli says.
The U.S. Fish and Wildlife Service is expected to make an announcement next week as to whether or not monarchs should be added to the Endangered Species list. A public announcement could come Tuesday, Pelton says. The monarchs would not automatically join the list if the agency determines they should be; a public process would then begin before the species would be listed.
The Eastern monarchs are also suffering losses, down about 70 percent from last year, Pelton says. The Eastern monarchs migrate to fir tree forests in Central Mexico, along with a portion of the Western monarchs. The Center for Biological Diversity announced in March that overwintering monarchs in that country during the 2019-2020 season had decreased by 53 percent from the year before.