Tigers on Market Street Shaping SF

Tigers on Market Street Shaping SF

Amber Hasselbring and Liam O’Brien gave an info-packed talk about the Western Tiger Swallowtail (Papilio rutulus) and the planning of Market Street. The talk was a lively kick-off for Shaping San Francisco’s 2013 TALK Series. If you didn’t make it, listen to the talk online.

The phenomenon of the butterfly and its behavioral adaptation to Market Street was first noted by lepidopterist Harriet Reinhard in 1987. During the 1960’s and 70’s the London Plane Tree (Platanus X acerifolia) – one of the butterfly’s known larval food trees – was planted en masse in the heart of the City. The London Plane, planted in cities in Europe and throughout the US are a hybrid between the Oriental Plane (Platanus orientalis) and American Sycamore (P. occidentalis). In combination with these trees, the canyon effect of tall buildings, the dappled sunlight, and the presence of underground water, we have actually created butterfly habitat!

Despite this hostile environment, males and females fly above the canopy looking for mates, females lay eggs on tree leaves, caterpillars feed on foliage then pupate, and adults emerge the next spring to repeat the cycle. The butterfly overwinters as pupa attached to tree bark. And, this insect is just the beginning of the story. Hasselbring and O’Brien received a Seedfund grant to survey the birds, insects, plants, water, and nectar resources that make up this unusual Market Street habitat.

Hasselbring and O’Brien’s proposal is to bolster and celebrate this phenomenon by sharing what they’ve learned with the Better Market Street plan so it can include known larval food trees, nectar flowers and other resources for City critters.

Are you excited? Now, Tigers on Market Street is building a coalition of support, and you can help. Provide your feedback to the Better Market Street team, and spread the word. Send this to someone you know who may be interested!