‘Beefy’ monarch butterflies are leaving the coast. How scientists (and you) can track them

If you’re out in nature this weekend, you might see people combing spots in search of one thing: monarch butterflies.

The community science initiative, known as the Western Monarch Count, is led by the Xerces Society, a conservation nonprofit that looks for the insects annually. This is the last count for the year, and it runs through Jan. 11.

The count is run mostly by hundreds of volunteers and partners of the Xerces Society across the state.

Why the count matters

Across California, monarch butterflies have been in steep decline in recent decades. The count is one of the ways the Xerces Society is trying to understand what’s happening and how we can help them recover.

The count looks specifically at the habits of a specific type of monarch known as overwintering monarchs, which travel hundreds of miles to our coast to escape harsh winters. They have special fat reserves in their tiny bodies, which make them beefier than breeding ones, says Sara Cuadra-Vargas, a  conservation biologist at the Xerces Society.

“ You can think of it … like if your great-great-great-great-grandfather was a superhuman that lived extra long and was extra large,” Cuadra-Vargas said.

The count happens over three periods, starting in October. This period is called the late-season count, which can show biologists how many monarchs are moving away from our sites and what mortality is looking like.

How you can help monarchs

They’re set for volunteers for this count, but you can volunteer for next year’s count by signing up to volunteer here. They require at least 15 hours of commitment — you’ll get set up with training.

Volunteers typically are assigned a site for the season and go out early in the morning when it’s too cold for monarchs to move. You’ll scan for the orange butterflies with binoculars and document things like habit quality and disturbances.

Cuadra-Vargas says our region has dozens of confirmed and potential overwintering sites, but the bulk of monarchs are seen in the central coast. In training, she tempers expectations.

“ We do still get overwintering monarchs here in Southern California, in Los Angeles and Orange counties,” she said, “but it’s a bit of more presence-absence that we’re looking for.”

That means you also may report where monarchs aren’t anymore, which is an important piece of data for biologists.

If you want to help out now, though, there’s still a few ways to do it:

• Help track where monarchs get their nectar by snapping a photo and sharing it through the Monarch Nectar Plant Database submission form.
• Add pictures of monarchs you see to the Xerces Society’s project on iNaturalist.
• If you want to get real high-tech, there’s a separate program that’s asking people to download a phone app to track specially tagged monarchs with solar transmitters.
• You also can go the low-tech, old-school route: Plant milkweed at home to give them something to eat.