LOS ANGELES — The anecdotes abound this year — friends reporting magical clusters of monarch butterflies on their walks, dozens of organizations offering free giveaways of native milkweed, and projects to restore habitat, even a lone monarch gracefully fluttering outside my window AS I’M WRITING THESE WORDS.
What more proof do we need?! Western monarchs are back! Problem solved! Crisis averted!
If only, says Emma Pelton, conservation biologist for the Xerces Society for Invertebrate Conservation.
Western monarch numbers are vastly improved over the winter of 2020-21, when researchers counted less than 2,000 of the iconic pollinators overwintering along the Central and Southern California coast. Over the past two years, those numbers have grown to nearly 300,000, according to the annual Western Monarch Counts around Thanksgiving and again around New Year’s.
But that’s still around 90% below the historic norms seen in the 1980s, Pelton says, when an estimated 1 million to 15 million monarch butterflies overwintered along the California coast, clustering on trees in numbers so great their combined weight sometimes broke branches. (Note that these numbers do not include the far larger population of Eastern monarchs, who migrate from the eastern and central regions of Canada and the United States to overwinter each year in the Transvolcanic Mountains of central Mexico.)
“People get excited about these year-to-year variations,” says Pelton, who oversees the organization’s Western monarch research. “And compared to 2020, it definitely looks better. But when we zoom out and look at the numbers three decades ago, we can see there’s still a long road ahead for a lot of recovery.”