Woodpeckers May Use Wood-Rotting Fungi to Help Them Drill Holes

From their chisel-like beaks to their shock-absorbent skulls, woodpeckers are built for drilling holes. But new research reported by New Scientist suggests that one species may be using spores from wood-eating fungi to make their jobs a little easier.

The new study, published by the Royal Society [PDF], was lead by Michelle Jusino of the U.S. Forest Service Center for Forest Mycology Research in Wisconsin. After catching red-cockaded woodpeckers from a North Carolina field site and swabbing their beaks, wings, and feet, researchers found traces of fungal spores known to rot wood. The same spores could also be found in the woodpeckers's tree cavities, but whether the birds were carrying them there or they were growing spontaneously was not yet clear.

To figure out the fungi's origins, the team then drilled holes in 60 trees and covered 30 of the holes with screens to prevent woodpeckers from fitting through. After 26 months, the holes the birds could access showed fungal growth more similar to their natural homes than those that had been barricaded.

While these findings suggest woodpeckers are bringing fungi to the trees and not the other way around, there's not enough evidence to say whether or not they have a symbiotic relationship. To do that, scientists would have to compare how long it would take woodpeckers to drill through trees infected with different fungi strains. The experiment would be quite a commitment, considering it can take red-cockaded woodpeckers up to eight years to finish their holes.

At one point, over 1.5 million cockaded woodpeckers inhabited the southeastern U.S.—that number has since dropped to 15,000. While they are still considered endangered, the species is in much better shape than it once was, thanks in part to conservationists drilling partial cavities in trees to speed up their home-building process.