LONG-TERM stress may be healthy for some animals. Mountain chickadees do better at some tasks when stressed than when not.
Stressed animals produce high levels of corticosterone, but too much of the hormone for too long can cause brain cell death, learning problems and memory loss. However, Vladimir Pravosudov of the University of California, Davis, found that chickadees given implants that release small doses of the hormone into the brain for three months were far better at finding seeds hidden in the lab than birds without the implants.
He thinks the stress hormone helps birds relocate hidden seed caches under…
