Scientists saving Darwin finches 1 pesticide-soaked cotton ball at a time

Scientists aren't exactly sure when the nest fly Philornis downsi first showed up on the Galapagos Islands, but their population began exploding in the 1990s -- which was and still is bad news for island birds, whose offspring are highly susceptible to the fly's larvae, blood-sucking parasitic maggots. "The birds have no history with these flies, which is why they are sitting ducks," explained biology professor Dale Clayton. "From the perspective of the birds, these things are from Mars." Luckily, for the birds and fans of biodiversity, Clayton, along with students and research colleagues from the University of Utah, have developed a solution: self-fumigation. Biologists working with wildlife on the Galapagos have begun arming area birds with cotton balls soaked in a mild pesticide called permethrin. The birds then incorporate the cotton into their nest-building process, helping to eradicate or prevent a maggot infestation. Benefitting from the new technique are several species of endangered mangrove finches made famous by Charles Darwin and his The Origin of Species. "We are trying to help birds help themselves," explained Clayton. Biology doctoral student Sarah Knutie co-authored a recent study with Clayton on the effectiveness of the technique. Their research was published this week in the journal Current Biology. "Self-fumigation is important because there currently are no other methods to control this parasite," said Knutie. Clatyon and Knutie's research showed not only that the parasite could be wiped out with just a one percent permethrin solution, but also that finches showed no preference for pesticide-soaked cotton balls verse non. Biologists have used permethrin to spray the nest and dens of other birds and mammals before, but the process is labor intensive and little research has been done to measure its effectiveness. Scientists hope that spraying materials like cotton balls or piles of twigs -- things animals naturally incorporate into their nests and homes -- will make parasite eradication efforts more effective and efficient.