A San Francisco Butterfly: The Variable Checkerspot

Cover photo: © Jamie Chavez, 2013, some rights reserved.

Learn more about the small butterfly that’s making a comeback around the San Francisco Bay Area.

Cover photo: © Jamie Chavez, 2013, Flickr Photo Album, some rights reserved.

The Presidio’s population of variable checkerspots became locally extinct in 1978.

Variable checkerspots are a part of a program working to reintroduce native species back to the Presidio in San Francisco. The Presidio’s checkerspot population became locally extinct in 1978 due to the loss of habitat. Park restoration efforts are currently working on the Presidio’s native habitats, resulting in 50 acres of native habitat restored thus far. With the hopes of bringing the butterflies back, 1,500 caterpillars were collected from other parts of the Bay Area and reintroduced to the Presidio in 2017.

If successful, the Presidio will become one of two areas in San Francisco that hosts the variable checkerspot butterflies (the other at Laguna Honda Reservoir). The primary cause of their decline in the area has been the loss of habitat across the city. With efforts such as those at the Presidio, we can hope that we’ll be seeing more of this beautiful butterfly.

Variable checkerspot caterpillars are spiny, and the butterflies are black with checkers.

Variable Checkerspot caterpillars are mostly black, with light dots that form bands along their body. They are covered in black and orange spines.

Butterflies are mostly black-brown, with yellow and orange checkers. Their wingspan is 1.25 – 2.25 inches.

Variable Checkerspot Caterpillar
Variable Checkerspot caterpillar on an English Plantain at Purisima Redwoods Preserve

Variable checkerspots live on the west coast of the U.S.

Variable Checkerspots can be found along the Pacific Coast,and as far inland as Wyoming and Colorado. They prefer chaparral habitats (semi-arid areas composed of mostly shrubs), open forest areas, and alpine tundras.

Variable checkerspots use many native and non-native plants for food.

Caterpillars will use beeplant, Indian paintbrush, snowberry, honeysuckle, monkeyflower, English plantain, and many others as host plants. Adults will feed on nectar from California Buckeye, Squawbush, Yerba Santa, and thistles (to name a few).

Resources to learn more:

Author: Taylor Crisologo

Taylor studied biology at Cornell University, where she worked with the Cornell Lab of Ornithology on projects ranging from breeding herring gulls off the coast of Maine to dancing lyrebirds in Australia’s Blue Mountains. When she’s not researching great places to experience Bay Area nature, you can find her birding or reading a book at home with her husband and their two indoor cats (Max and Penelope).

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: