Darwin’s Finches Fight Off Parasitic Maggots with Treated Nest Fibers

Researchers apparently have discovered a unique way to help Darwin’s finches on the Galápagos Islands fight off the parasitic maggots threatening their survival, according to a new report in the journal Current Biology. While working in the Galápagos, scientists
Darwin's finch with treated cotton
A Darwin’s finch collects treated cotton for its nest
from the University of Utah noticed that the finches often collected cotton and other fibers to weave into their nests. The researchers decided to provide the birds with cotton treated with permethrin — a mild pesticide, commonly used to treat head lice in children, that is safe for birds — hoping the finches would incorporate the fibers in their nests. Finches near the test sites did just that, and their “self-fumigated” nests contained about half as many parasitic maggots — which infest and can kill newly-hatched chicks — compared to nests with untreated cotton. Darwin’s finches and other bird species in the Galápagos have suffered steep population declines since the flies showed up in large numbers in the 1990s.