A new report outlines how to prioritize research and conservation efforts to revive the western monarch butterfly.
“Western monarch numbers have declined really significantly in the past 30 years to some of the lowest levels on record,” said Hillary Sardiñas, a pollinator coordinator at the California Department of Fish and Wildlife.
Thirteen state and federal agencies contributed to the report called “Conservation Priorities for Western Monarchs in California” — including Fish and Wildlife, the California Coastal Commission, and the U.S. Forest Service.
The document lists top priorities for the next three years, like tracking the successes and failures of habitat projects so it’s clear what’s working and what isn’t.
Another priority is growing access to native plants.
Sardiñas says that in order to successfully breed, monarchs need milkweed, a plant that resprouts every spring.
The problem is, the butterflies have started breeding earlier and earlier, likely due to warming temperatures.
“Sometimes they're getting a different cue than the milkweed is from the environment,” she said. “And so we see this mismatch where they might not be finding the appropriate plants to breed on.”
To help resolve the conflicting schedules, the report identifies four milkweed species that sprout earlier in the year — including California milkweed and heartleaf milkweed.
Sardiñas said it’s important to plant those early-emergers in the habitats where monarchs spend their winters, like the Goleta Monarch Butterfly Grove at Ellwood Mesa.
The report also stresses the need for a better understanding of the habitats western monarchs migrate through. The insects need nectar from native plants to fuel them on their travels, but “the density and distribution of nectar plants required during migration is poorly documented,” according to the report.
Sardiñas said that information is important, in order to “make sure that there's milkweed distributed within the appropriate distance, so that it's like stepping stones for them to migrate.”
However, monarch butterflies don’t only need milkweed. Sardiñas also encourages communities near overwintering sites, like San Luis Obispo, to plant a range of nectaring native plants to help fuel the butterflies as they migrate.
“ Plant native plants, have as many as you can in your gardens,” she said. “ The nectar is what helps fuel their flight and helps them survive.”
