Butterfly graffiti directs migrating monarchs to urban food sources.
Monarchs regularly pass through wide swathes of human settlement as they migrate each year from wintering sites in Mexico to 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.
Papalotzin is a project to follow the migration of the monarch butterfly from Canada to Mexico in an ultralight airplane (they call it their big butterfly). They've made it as far as NYC so far and are blogging and taking pictures as they go. (via gurgly)
Butterfly team colors may discourage inter-species mating and pave the way for the development of separate species. "This process, called 'reinforcement', prevents closely related species from interbreeding thus driving them further apart genetically and promoting speciation."