Finches in the Galapagos Islands were provided with pesticide-treated cotton to put in their nests, protecting their offspring from harmful parasitic fly maggots.
"We are trying to help birds help themselves," biology professor Dale Clayton, senior author of a study outlining the new technique said in a University of Utah news release.
"Self-fumigation is important because there currently are no other methods to control this parasite," University of Utah biology doctoral student Sarah Knutie, the study's first author said in the news release.
The parasitic maggot first showed up on the island in the 1950s, so the birds have very little defense against them.
The pesticide, permethrin, is believed to be safe for the baby birds.
"It might kill a few other insects in the nest. This is the same stuff in head-lice shampoo you put on your kid. Permethrin is safe. No toxicologist is going to argue with that. The more interesting question is whether the flies will evolve resistance, as human head lice have done," Clayton said.
The parasites feed on the blood of the nestlings and nesting mother, they often kill all of the nestlings once they infest.
Knutie got the idea for the study when she saw the finches nipping at her clothes line to get material for their nests.
The researchers tested this idea by looking at 26 active nests, 22 percent contained cotton. Thirteen of the nests contained cotton treated with permethrin, nine had cotton that was not treated.
After the birds finished nesting (which took about three weeks) the researchers collected and dissected the nests to see how many maggots were present.
The team found "self-fumigation" had a "significant effect on the number of fly maggots infesting each nest.
"If the birds insert a gram or more of treated cotton - about a thimbleful - it kills 100 percent of the fly larvae," Clayton said.
