Extinct Xerces Blue Skies Project's Journal

This April, we released Silvery Blue butterflies in the Presidio to function as ecological surrogates for the extinct Xerces Blue butterfly.  The release site was carefully chosen near where Xerces last fluttered within the restored dunes in Presidio National Park.  This collaborative endeavor represents over 25 years of dedicated work from many partners, ranging from habitat restoration to scientific research, from field trips to outreach all with the collaboration of incredible stewards in the Presidio and the source sites found in Monterey County.

The Silvery Blue butterfly, a close relative of the Xerces Blue, inhabits a wide range of environments from Baja California to Nova Scotia.  The Academy's science efforts focused on finding thriving populations of Silvery Blue butterflies that were genetically ‘close enough’ and importantly, that shared Xerces' preferred climate, habitat, and host plant.   We used two lines of evidence, genomics, and ecology to answer the questions: What was Xerces? How is it related to the Silvery Blue butterfly, its closest relative? Which Silvery Blue populations make the best surrogates?

This community project was brought to us by external partners. They and our Academy teams deserve both credit and thanks.

For more, see the Academy press release: "California Academy of Sciences and Presidio Trust repopulate sand dunes with relative of extinct Xerces Blue butterfly."  

Your observations will be aggregated on this project.

Thanks to all who made this amazing work possible!

Durrell

Partner organizations: Dedicated staff from the following institutions brought us to this moment: Presidio Trust, Presidio National Park, GGNRA, Creekside Science, Revive and Restore, University of Florida McGuire Center for Lepidoptera and Biodiversity, University of California Santa Cruz Fort Ord Natural Reserve, California State Parks--Monterey County, multiple reserves from Marin to Monterey County, and the Academy.

Academy teams: To answer these questions, our Academy Science team employed our core facilities including Entomology collections, the Center for Comparative Genomics, and our Scientific Computing facility.   We also did several years of collaborative fieldwork to pinpoint thriving populations of Silvery Blues from which to gather butterflies for translocation and release in the Presidio. Academy staff also leaned into telling the story across comms, creative, exhibits, online video, and other channels!

Hi all,

Silvery Blue butterflies were early this spring as assessed by our fieldwork, our networks of partners, and especially by looking at iNaturalist of course!

In the field, we had our first butterflies flying in Monterey County on March 12. We had peak numbers with > 30 unique detections at Garrapata State Park and > 60 unique detections at the Fort Ord Natural Reserve on Tuesday and Wednesday respectively.

We've also seen several other species including: Echo Azure, Acmon Blueand Coastal Green Hairstreak. The latter are pretty apparent at restored dune sites in the Presidio of San Francisco.

Speaking of the Presidio, if you go anywhere in the Presidio this weekend, keep your eyes out and photograph any blues you might see! (more exciting news on that Monday).

Best,

Durrell

In an attempt to focus the host plant list to verified records today I added verified species from Calscape. We can keep track of future additions here (and potentially remove genera that don't have specific records in California as we find more specific species information).

This project collects all observations of the extinct Xerces Blue's closest relative the Silvery Blue. We also collate information in Xerces' and Silvery Blue's known host plants. Right now these include Deerweed, Vetches, and Lupines, but the latter two genera are too broad, so bear with us as we add specific host species for Silvery Blues to the taxon list.

Xerces declined due to the construction of the Western half of San Francisco's 'Outerlands', which removed Xerces and its host plant Deerweed's dune habitats. This trend accelerated after the 1906 Earthquake.

Our team is using the Academy's collection of Xerces specimens to reconstruct its genome and identify candidate replacements. To date, our team has extracted DNA from and sequenced genomes of 80-to-100-year-old museum specimens of the extinct Xerces Blue* and its close relative, the Silvery Blue (Glaucopsyche lygdamus).

Our work is in collaboration with the Presidio Trust and Revive and Restore.

For more information see the following:

• Revive & Restore: Wild Genomes Projects
• Alta Online article by John Markoff
• Bay Nature Article by Liam O'Brien
• article on the Xerces story by Xerces society found Robert Michael Pyle

*Xerces has been variously considered as a separate species (Glaucopsyche xerces) or as a subspecies of the Silvery Blue (Glaucopsyche lygdamus xerces), a question that this project will help resolve.