PISMO BEACH, Calif. -- The Western Monarch butterfly population that overwinters in California has dropped to devastating levels, with only 1,914 individuals spotted in this year's winter count.

They've been declining for decades, but experts say they may have reached an extinction threshold in 2018 when volunteers only counted 30,000.

Angela Laws, the endangered-species conservation biologist for the Xerces Society, said the population appears to be collapsing.

"It's a 99.9% drop from the '80s, when an estimated four million monarchs were overwintering along the California coast," Laws outlined. "It's a big drop in their population. It's very worrying."

She noted the stark decline reasons include loss of native milkweed habitat, pesticide use, development at their overwintering sites, and climate change.

The Western population returns each winter along the California coast, from San Diego to Mendocino counties, with a particular concentration near Pismo Beach.

Deedee Soto, the farm-bill pollinator conservation planner for the Xerces Society, works with the Natural Resources Conservation Service to help farmers and ranchers plant pollinator habitat on their land, mostly native milkweed and nectar plants.

"The rangelands are particularly important for monarchs because the habitat is more so protected from these heavily developed areas and areas where there's a lot of pesticide use and some habitat degradation," Soto explained.

People can help save the monarchs by reducing pesticide use in their yards and planting monarch-friendly plants.For tips, check out savewesternmonarchs.org.

The Endangered Species Coalition asks supporters to write letters to Congress urging lawmakers to pass the Monarch Act, a bill that would provide funding for projects to save the species.