Woodpecker biologist Daniel Saenz now has the data to show that frustrated scientists aren't imagining things. Pileated woodpeckers really are attracted to the homes of red-cockaded woodpeckers.
Saenz of the Wildlife Habitat Laboratory in Nacogdoches, Texas, frets over the cavities that the small, endangered red-cockaded woodpeckers peck out of healthy pine trees. The 8-inch-long birds routinely spend 6 years excavating before a cavity reaches the right size. A finished cavity houses a single bird.
The pileated woodpeckers, like most of the clan, usually whack their cavities out of dead trees in which a fungus has already softened the wood.
However, Saenz and other biologists have seen pileated woodpeckers start slamming away at the painstakingly excavated red-cockaded cavities, making the openings too large for the original owners to tolerate when the invader abandons the task. The 16-inch-high birds "can ruin years of work in one afternoon," laments Richard Conn