Downtown San Francisco, California

Tigers on Market Street

Amidst the bustle of Market Street, new homes are being developed – for the Western Tiger Swallowtail Butterfly, that is! Right now, plans are hatching for new habitat with the butterfly’s favorite host plants. Think, green roofs & canopies, native plants’ hanging baskets, exhibition stations and more!

Curious? Download the iNaturalist app! Help our citizen science efforts by discovering new species and adding your own observations to the Tigers on Market Street project.


Project Details


What is Tigers on Market Street project? 

Western Tiger Swallowtail butterflies (Papilio rutulus) have been thriving among the bustle of Market Street since the 1980s. They lay their eggs on the London Plane trees lining both sides of the street living a complete life cycle there (and in nearby parks). You see, from the Tiger’s perspective, Market Street with its tall buildings bordered by trees and nearby sun-filled plazas and parks, resembles its natural habitat: a river canyon with nectar flowers in nearby meadows! The Tigers on Market (TOM) Street project began in 2013.


Where is Tigers on Market Street project?

The project is located along Market Street in San Francisco. It also includes Sue Bierman Park at the corner of Washington and Drumm Streets.


Why is the Tigers on Market Street important?

The project engages the public in this unique butterfly phenomenon and connects people to wildlife in San Francisco—one of the most densely populated cities in the US—a city on the cutting edge of technology, entrepreneurship, and innovation. The Bay Area is a biodiversity hot-spot, defined as, "... a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction." With this well-earned reputation, the City has recognized this responsibility and is committed to safeguarding urban species by restoring their habitats.

When nature thrives, humans thrive! As Richard Louv describes in his concept of “nature deficit disorder”, nature is not an optional part of human life. We are, in fact, biologically hardwired to connect with nature. The TOM project seeks to reestablish this human-nature connection. Motivated by large-scale public health problems such as obesity, depression, and pervasive nearsightedness, all associated with time spent indoors, scientists are looking at how nature affects our brains and bodies. Building on advances in neuroscience and psychology, they’ve begun to quantify what once seemed divine and mysterious. Measurements of stress hormones, heart rates, brain waves, and protein markers all indicate that when we spend time in nature, our physiological and psychological health soars.


What is the goal of the Tigers on Market Street project?

We want to demonstrate how wildlife habitat can inform urban design. As part of the city's plans for a Better Market Street Project, a multi-million dollar effort to reinvent San Francisco’s central artery and the complete redesign of San Francsico's civic spine, Nature in the City is advocating for biological diversity and is advisor, advocate, and fundraising partner in the redesign process. We’re in ongoing conversation with public and private agencies including SF Public Works, SF Planning Dept., Building Owners and Managers Association of SF, SF Dept. of the Environment, Yerba Buena Community Benefit District, SFRPD and with Market Street businesses to create more habitat so that the Tigers will thrive. Think, field stations at the Embarcadero and Civic Center as entry points to the route with butterfly overlooks, mobile classrooms, green roofs, exhibition stations, and opportunities for citizen (yes, you!) science projects.  


How can I take part?

Become a corporate sponsor and support habitat design and implementation. Corporations will have the opportunity to sponsor the project at varying levels. Or, if you simply work at a Market Street business, get in touch to find out how you can help. Stay tuned for more detail or contact us to learn about next steps.



A Field Guide to the Wildlife of Market Street [pdf]

Wester Tiger Swallowtail Nectar Plant List [jpg]

Nature in the City Map Snapshot

Western Tiger Swallowtail butterfly in Downtown San Francisco



Market Street
San Francisco, CA