Francine Kiefer
Mon, December 6, 2021
Naturalist Danielle Bronson is ecstatic. The butterflies are back. Specifically, the Western monarch butterfly – more than 20,000 of them hanging in clusters from branches in elegant eucalyptus trees or fluttering around this conservation grove on the central California coast.
Last year, the count in the Pismo State Beach Monarch Butterfly Grove totaled only 200, in what is a top overwintering spot for monarchs west of the Rocky Mountains. The entire recorded population numbered less than 2,000 last year – down from millions in the 1980s. Experts feared this year might mark their end. Instead, the butterflies are experiencing a resurgence, though no one knows exactly why or if their upward trajectory will continue.
“I’m thrilled, because having 2,000 as the entire population, it was a blow to the face actually,” says Ms. Bronson. As a schoolgirl, she visited this grove, awed by hundreds of thousands of monarchs so plentiful they covered tree trunks. The sight inspired her to a career with the state park service, where she now works as a park interpreter and educator. “Last year was devastating, but this year I’m very hopeful.”
Ms. Bronson calls monarchs “the Hollywood species,” celebrities in their own right, flitting about in gorgeous orange-and-black gowns designed by Mother Nature. As stars of the pollinator world, they also serve as high-profile messengers about what is happening to this all-important group.
Both Western and Eastern monarchs – indistinguishable in genetic makeup but distinct populations because of their location on either side of the Rockies – have suffered severe declines since the early 1990s. The Eastern monarchs, which migrate to Mexico where they overwinter and mate, have seen their numbers drop by about 70%. The Western population, which migrates from northern states and parts of Canada to the California coast, is much worse off, plunging by 99%. The U.S. Fish and Wildlife Service is expected to add monarchs to the list of endangered species in 2024, says Sarina Jepsen, director of endangered species for the Xerces Society for Invertebrate Conservation.
The society organizes an annual Thanksgiving count of the Western monarch, at about 250 overwintering sites throughout California, Mexico’s Baja California, and a few places in Arizona. Volunteers arrive at first light to count the butterflies in their clusters. Any later, and they risk an overcount as the sun warms up these cold-blooded creatures and they begin to fly about.
These monarchs are a special generation that lives for six to eight months. After overwintering and mating, the females fly off and lay their eggs on milkweed, usually inland, on which the emerging caterpillars feast until they turn into a chrysalis and, finally, butterflies. Those adults typically live for only 30 days, with successive generations traveling on before the fall migration begins again.
This year, the butterflies arrived early. A preliminary tally of the Thanksgiving count finds more than 100,000 Western monarchs, a stunning 4,900% increase over last year. The final result will be announced in January. It’s encouraging, but “not a recovery,” cautions Ms. Jepsen, who cites a tendency of insect populations to bounce around.
“We’re really grateful it didn’t bounce to zero. What it means is we have a little bit of time to work toward recovery, but it doesn’t mean the population has recovered,” she says. As a reference point, a population under 30,000 is considered to have entered the “extinction vortex,” she says.
Many factors contribute to the decline of the monarchs. Overwintering habitat is lost to development. There’s less milkweed – the only food that monarch caterpillars eat – and fewer nectar-producing plants to nourish the butterflies. Pesticides, wildfires, and climate change all play a role, according to the Xerces Society. Because of the many reasons for decline, it’s not possible to pinpoint what’s behind this year’s resurgence. “We really can’t interpret it,” says Ms. Bronson.
But experts do know that restoring habitat and planting nectaring plants and milkweed can help. The massive infrastructure bill signed by President Joe Biden in November included $10 million to fund pollinating plants along roads and highways. The Monarch Act, sponsored by Oregon Sen. Jeff Merkley and California Rep. Jimmy Panetta would provide $125 million to save the Western monarch.
Individuals can play a role, says Ms. Bronson, though she explains that the messaging about milkweed is a bit complicated. It should be planted away from overwintering sites – if it’s too close, it will encourage the butterflies to come out of diapause and mate sooner than they should. And the plantings should be native milkweed. Tropical milkweed, often sold by big-box stores, can house a harmful parasite and should not be used, she advises.
The simplest way to help, she says, is to grow nectar-producing plants to give butterflies energy during their journey and while overwintering. “You really can’t go wrong on that one, because you’re not just helping monarchs, you’re helping all pollinators.” The Pismo Beach conservation site, just off of Highway 1, has a nearby garden with coyote bush and senecio, a flowering succulent, to feed the monarchs.
Visitor Suzi Goodwin got the message. A local, she often visits the grove at this time of year, especially if she has company. She is delighted with the noticeable increase in butterflies, and loves the grove for its peaceful feel and scent. She has put in plants friendly to butterflies and bees at her house in Santa Maria, about 20 miles from the grove. “We did our homework before we bought our plants,” says the retiree.
Of course Ms. Bronson hopes the monarch numbers will continue to go up. She wants her 2-year-old son to see what she saw as a little girl. “And not just my kid. I get utter joy when you have school groups coming out here, and the ‘oohs’ and the ‘ahs’ and the ‘wow.’ And the smile that you can see in their eyes. That also brings hope.”
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