Monarch Butterflies Found in Mount Diablo Region!

Monarch on a milkweed

Monarchs on Our Milkweeds in Seven Different Places

We have been mapping where milkweeds are found on Save Mount Diablo’s lands and around the greater Mount Diablo region in an effort to study, understand, and strategically plan restoration habitat for monarch butterflies.

Recently, we found monarch caterpillars on some of our milkweeds, specifically on California milkweed (Asclepias californica). We’re extremely excited—we have been looking for monarchs on our properties and around the mountain for years, and this is the first time we’ve seen them.

So far this year, we and our partners have found monarch caterpillars in seven different places: at four different Save Mount Diablo properties, in two places within Mount Diablo State Park, and at one private property near the park.

Monarch on a milkweed

Save Mount Diablo Land Programs Director Sean Burke has been looking for monarchs in our region since 2016 and hadn’t seen monarch caterpillars in the Diablo region until this year.

The Mount Diablo region is part of the migration route for the western population of monarch butterflies. Monarchs cross over our area to get from the California coast to points north and east during the spring migration.

Collecting Seeds and Propagating More Milkweeds

The importance of California milkweeds

Milkweed on Mount Diablo

California milkweed (Asclepias californica).

We will also collect milkweed seeds with the California Department of Fish and Wildlife and then take them to the Watershed Nursery in Richmond.

The Watershed Nursery will propagate the seeds and give Save Mount Diablo half of the milkweed starts for free. The other half will be available for purchase by Save Mount Diablo, public agencies, or the public.

We are focusing mostly on collecting California milkweed (Asclepias californica) seeds. That’s because the species is more rare to the area and the monarchs are utilizing it rather than another species of milkweed that is native to our area, narrow leaf milkweed (Asclepias fascicularis).

Mapping Milkweeds, Planning Restored Habitat, and Applying for Funding

Monarch on a milkweed

A volunteer has recently joined our efforts and is helping us to map more of the extent of California milkweed, in coordination with our other mapping efforts of the narrowleaf milkweed that we built last summer.

Save Mount Diablo has been working with the East Bay Monarch Work Group for a number of years now as well. Together with other partners, we strategize and collaborate on projects to educate the public and restore and build habitat for monarchs.

We are also applying for funding for the milkweed project so that we can expand this restoration project and help build habitat around Mount Diablo for this very important pollinator.

Monarch on a milkweed

All photos by Sean Burke

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