Graffiti for Butterflies
Directing monarch butterflies to urban food sources along migratory routes in North America
GFB uses images of milkweed flowers to broadcast the location of food sources to monarch butterflies. In the prototype at left, the graffiti is placed on a wall above an actual milkweed plant in New York City, signaling the presence of nectar to hungry monarchs in the vicinity.
Monarchs regularly pass through wide swathes of human settlement as they migrate each year between wintering sites in Mexico and summering grounds in the United States and Canada. GFB is the equivalent of a fast-food sign on a highway, advertising rest stops (waystations) to monarchs traveling through the area.
Milkweed flowers have natural ultraviolet (UV) patterns that are recognizable to monarch butterflies. These patterns are invisible to us because we can’t see light in the ultraviolet spectrum. GFB uses sunblock to paint the graffiti in a way that mimics these natural ultraviolet properties. (Sunblock is perfect for this, because it’s designed to reflect ultraviolet light away from our UV-sensitive bodies— it’s essentially a cheap and easy UV spray paint.)Milkweed leaves are the monarch caterpillar’s sole food source. In this video, a monarch visits a balcony in New York City. It feeds and lays eggs, later hatching into tiny hungry caterpillars.
Marisa Olson’s review of Graffiti for Butterflies at Rhizome:
www.rhizome.org/editorial/411
The Metafilter comment thread on this project can be found at:
www.metafilter.com/73817/Graffiti-for-Butterflies
BLDG Blog covers the project at:
bldgblog.blogspot.com/2008/09/artificial-migration-routes-for-monarch.html
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Here are a couple of my thoughts stimulated by this idea.
1) Many flowers vary across the surface of the petals in how much UV light they reflect. The resulting patterns are invisible to our naked eye, but most nectar feeding insects can see them. This means that different parts of the flowers are perceived by insects as being different colors, and insects do use these UV patterns to recognize and orient to flowers. Do milkweed flowers have such UV patterns as is claimed on this page? I could not find any images on the web to confirm this and none is provided on the web page.
2) Contrary to what is suggested on this web page, sunscreen works by absorbing, not reflecting, UV. Chemicals in the sunscreen absorb UV light thereby preventing it from reaching and burning our skin. Making a sign or coating a flower with sunscreen would make a surface that would reflect very, very little UV, which would also change its color to an insect.
This plant does not look like the milkwood plant I know. The flowwers are mauve and grow in clusters. I love the idea, though, of guiding monarchs through populated areas. I live in the country so this is not necessary.