Butterflies in the City

August 2014

Post by Timothy Beatley

Timothy Beatley, PhD, is the Teresa Heinz Professor of Sustainable Communities & Chair of the Department of Urban & Environmental Planning at the UVa School of Architecture.

Few creatures capture our imagination or spark a sense of glee when we see them more than butterflies. It is likely a combination of their mysterious life cycle, and their ability to so profoundly metamorphose, but also undoubtedly the beauty of their colors, shapes and the serendipitous and charming ways in which they propel themselves forward.

Many butterfly species are not doing very well, most notably the Monarch.  A recent Canadian study found a significant decline in the Milkweed, an essential food plant, in the Corn Belt, over the last couple of decades (e.g. see http://www.uoguelph.ca/news/2014/06/habitat_loss_on.html), a function of herbicide-intensive agricultural production.

In the face of these threats, cities can play an important conservation role. Butterflies offer special opportunities for connection and we have been watching a number of interesting and creative efforts in cities around the US and the world. Cities can take the lead in helping to advance conservation, as St. Louis is doing with its Milkweeds for Monarchs Initiative. The mayor of that city (more fully described in the accompanying article by Carla Jones), has set the goal of planting 250 milkweed gardens in the City, to commemorate St. Louis’s 250th anniversary. The city itself has committed to planting 50 and has challenged individuals and private organizations to plant the remaining 200 gardens.

A May article in the St. Louis Post Dispatch with the title “Mayor Slay Promises…More Butterflies,” suggests the uniqueness of this mayor’s priorities and commitments, and is a recognition of the important quality of life benefits delivered by nature. Perhaps a key metric of a biophilic city is the number of urban neighborhoods, or percentage of the city’s residents, likely to see butterflies?

In our partner city Singapore, there are more than 280 native species of butterflies to be found. Any visit to this city in a garden will likely yield multiple sightings. On a visit in 2012, I found myself constantly scurrying after and photographing butterflies there (including the beautiful Plain Tiger below).  It was a dimension of beauty and fun and natural connection not to be understated.

In Singapore there is an active group of citizens—the ButterflyCircle—engaged in watching, studying and photographing butterflies. And there is even a Butterfly Trail along Orchard Road, one of the main shopping areas.  This 4-km route, from the Botanic Garden to Fort Canning Park, connects 15 “butterfly spots.” 

When it comes to butterflies, few cities have done as much as partner city San Francisco. For many years, the local non-profit Nature in the City has spearheaded efforts to connect small parcels of land into habitat corridors for the locally endangered Green Hairstreak butterfly. Several years ago I visited one location in the city where a series of seven parcels were being restored and re-planted through the city’s Street Parks program, run by San Francisco’s Department of Public Works, providing the chance for citizens and neighborhoods to create gardens and gathering spaces in the medians of roads. These parcels are part of a larger Green Hairstreak Corridor, seeking to connect two  hill top populations of the butterfly—whose habitats had been fragmented by urbanization– and to begin to see this mosaic of small parcels, including parks and outcrops, as a more holistic landscape and habitat. The Corridor is the site of Nature in the City-organized BioBlitzes and Volunteer Days.

The latest chapter in San Francisco has been an effort to study and raise awareness about the Western Tiger Swallowtail butterflies that inhabit Market Street, the main commercial and pedestrian corridor in the city’s downtown. Artists and lepidopterists Amber Hasselbring and Liam O’Brien have taken to the field to study these butterflies and have found a remarkably resilient urban population. The butterflies live in and patrol the canopy of London plane trees, in an urban environment that largely mimics the stream or river corridor that would be their natural home.

A “convergence of happenstance,” is how Hasselbring and O’Brien explain it to me.  “It’s sort of using Market Street as if it were the Colorado River cutting through the Grand Canyon,“ O’Brien tells me. This realization has led the two to argue that the important habitat provided by the trees should be taken into account when the street is re-designed (one option being considered would be to eliminate many of the trees, though this now seems unlikely thanks to their advocacy).

“We have an opportunity to connect so many people in a dense downtown to a moment in nature, and that’s really the thrilling thing,” O’Brien says.

How the renovation of the street can accommodate and further enhance habitat for the butterflies remains to be seen, but Hasselbring and O’Brien are working on this through their project “Tigers on Market” (ideas range from butterfly kiosks to installing Swallowtail Swales with new nectar flowers).

The San Francisco story is a compelling one of how nature survives, indeed thrives, in the midst of dense urban environments. And as work in Singapore, St. Louis, and other cities show, butterflies can connect us to place, and to each other, and add an element of fascination and complexity to our otherwise hardscaped lives.