A Special South Bay Butterfly By Writer and Contributor Mary Simun
On June 1, 1976, the El Segundo blue butterfly was officially listed as an endangered species. This determination meant that additional resources would be provided by the US Fish and Wildlife Service to help the El Segundo blue butterfly increase its range and population size.
While most people are familiar with monarch butterflies that migrate from the interior of the USA to either Mexico or California through multiple generations, the El Segundo blue (Euphilotes allyni,) has a different life cycle approach. This butterfly is known as a single-brood butterfly, meaning that it only reproduces once a year within a specific time window. And to reproduce, it needs a specific host plant, the sea-cliff buckwheat (Eriogonum parvifolium), which grows on our local sand dunes and cliffs. View this short video all about the El Segundo Blue butterfly.
Loss of Habitat
The butterfly’s range extends from the Ballona Wetlands south to the Palos Verdes Peninsula. The primary threats to the ESB are loss of habitat due to coastal development and climate change. Changes in the host and nectar plants’ blooming season, which determines the butterflies’ ability to reproduce, along with sea level rise that may threaten the butterflies’ coastal habitat. By planting native gardens in urban spaces, we can help connect patch habitats and support struggling species such as the El Segundo blue.
South Bay Parkland Conservancy (SBPC), along with partner organizations is leading a decades-long effort to restore habitat for the endangered El Segundo Blue
Butterfly (Euphilotes allyni), and other native wildlife along its historic range, including on the bluffs of Redondo Beach and Hermosa Greenbelt, linking the natural habitat for this special butterfly.
How the Habitat Restoration Plays a Key Role
The South Bay Parkland Conservancy in conjunction with the USFWS and the Cities of Redondo and Hermosa Beach are diligently working to reconnect this critical and unique habitat that has been fragmented for many decades, with the goal of mitigating and reversing habitat loss due in large part to the loss of coastal dunes in Hermosa Beach.
Plant installations along the Redondo Beach Bluffs and Hermosa Greenbelt prioritize the host plant (Eriogonum parvifolium). As these plants have been reintroduced along their historic ranges, the butterflies have returned, including the endangered ESB, the Acmon Blue (Plebejus acmon), and the threatened Monarch (Danaus plexippus). By working towards reestablishing continuous habitat and interconnecting previously isolated patches of vegetation, the range of the ESB may one day resemble what it was. A proposal submitted in December 2024 to provide the monarch with protection under the Endangered Species Act.
In the last year alone, SBPC volunteers have dedicated more than 2,800 hours planting nearly 2,000 native plants to restore native habitat in key locations. But we can’t do this alone. We encourage coastal residents to plant these host plants and other native CA pollinator plants to ensure thriving habitats for pollinators. Together we can make a difference and bring the El Segundo Blue butterfly from the brink of extinction.
Spotting the El Segundo Blue
You can easily view the El Segundo blue butterflies in the summertime, especially in late June and early July. Currently, the easiest places to see the El Segundo blues are along our sandy beach dunes that have been planted with sea-cliff buckwheat plants and other native species at Torrance, Redondo, and Dockweiler Beaches. SIGN UP HERE for a guided walk with SBPC biologist and educators. Remember to respect the Butterfly Zone! One must not step on or near the sea-cliff buckwheat plants for fear of killing the butterfly’s chrysalis or caterpillars, so bring binoculars! You can observe the butterflies bouncing around the buckwheat plants, sipping nectar from the flowers, and even mating!
Anyone interested in supporting South Bay Parkland Conservancy or volunteering for various restoration efforts in the South Bay please visit https://www.southbayparks.org.
Mary Simun
South Bay Parkland Conservancy, Biologist and Educational Director
June 2025
Mary Simun, a Los Angeles native, relocated to the South Bay in 1997. She “retired” from the classroom in 2015 and has redirected all her resources into community service. Her continued mission on planet Earth is to inspire humans to experience a lifelong love of learning, discovery, curiosity, and child-like wonder.
As a Biologist, she has worked for the USNPS, USFS, and USFWS. Her love of Botany and environmental stewardship spans generations and she firmly believes that our relationship to photosynthesizers will define our future. She converted her front yard into an SBPC-certified native habitat, complete with a scavenger hunt, and gives away seeds and plants to anyone who passes by.
She began her formal education career at age twelve at the Cabrillo Marine Museum under the tutelage of John Olguin and from that point forward, education and science always went hand in glove. She is passionate about immersing young people in nature to combat Nature Deficit Disorder. Currently, she is a dedicated volunteer for the Friends of the RB Public Library, ESB, and South Bay LGBTQ Center.
She is passionate about life on this planet and her current personal goal is to become 100% fossil fuel independent. If you see her zooming about town on her solar-powered E-bike, complete with a pink leopard helmet, wave hello!