Searching for Xerces’ Successor: Silvery Blue Butterflies in SF

Explore the Presidio’s restored dunes with researchers and search for Silvery Blue butterflies—introduced in 2024 to fulfill the ecological place of the extinct Xerces Blue. Learn about the science behind environmental regeneration while observing the butterfly’s interactions with native Deerweed and other dune wildlife.

Note there will be two separate walks to accommodate the most people: Walk 1 from 10:45-12:00 and Walk 2 from 12:45-2:00. See below for meeting locations for each, and pick ONE under Tickets.

Walk Leaders: Dr. Durrell Kapan and Lew Stringer

Durrell is a Senior Research Fellow at the California Academy of Sciences, applying biodiversity science to conservation and regeneration. He leads the Academy’s Xerces Blue project, collaborating with the Presidio Trust, National Parks, California Agencies, local NGOs, and conservation scientists.

Lew is the Associate Director of Natural Resources for the Presidio Trust and manages a team restoring biodiversity in the Presidio. Lew has been instrumental in rebuilding the native dune ecosystem and leading conservation projects that support pollinators and other wildlife in the Presidio.

Nature in the City Host: Amber Hasselbring

Amber is the Executive Director of Nature in the City and helped launch innovative, creative projects and partnerships including: Green Hairstreak Corridor, Green Connections Plan, Crosstown Trails, Tigers on Market Street, BART/MUNI Canopy Living Roofs, Nature in the City Gardening, and Reimagining San Francisco.

Details:

Participants will walk through vital and restored dune ecosystems, once home to the Xerces Blue, to observe the habitat and search for Silvery Blue butterflies. The walk will cover approximately 1.5 miles on moderate terrain with sandy paths and some uneven ground.

Expect to learn about the historical ecology of San Francisco’s dunes, the science behind the project to reintroduce an ecological surrogate, and the role of butterflies in urban biodiversity. Stops will include key restoration sites where host plants like Deerweed (Acmispon glaber) are critical to the introduced butterflies and the web of life. This is an interactive experience—binoculars and cameras are encouraged!

Preparation:

Please wear comfortable walking shoes suitable for sandy and uneven terrain. Bring water, sunscreen, a hat, and layered clothing for variable coastal weather. Binoculars and cameras are encouraged for butterfly observation! Light snacks are recommended if you want to stay after the walk for more discussion.

Meeting Locations:

Morning Walk: The first walk will start at 10:45 at the entry to the Presidio Hills Dunes, at the intersection of Wedemeyer Street and Battery Caulfield Road. See map pin for exact meeting location.

Afternoon Walk: The second walk will start at 12:45 at the picnic tables at the Rob Hill Campground. Park along Central Magazine Road - feel free to ignore the parking restrictions.

Transportation and Parking:

Parking is available near the Presidio Landmark building:

The PresidioGo shuttle runs nearby but doesn't start until 11am on weekends.

The Muni 28 drops off on Park Presidio, a few blocks walk.

Weather:

Rain will cancel. We will email participants if we decide to cancel walk.

Cost:

This walk is FREE* to attend (with RSVPs kindly requested).

Donations (in cash or Venmo) can be made to Nature in the City on the day of the event. Special bonus! Everyone who donates $10 and above will receive a copy of the Nature in the City Map.

Or donate to Nature in the City using our secure online form, and we’ll send you monthly emails with a full events listing, local nature information, and access to more fun perks.

Info: The first walk option will start and end at Presidio Hills, with the option to continue chatting with a bag lunch at 12:00

Info: The second walk will start and end at the Rob Hill campground.

Host or Publisher Nature in the City