Mountain birds on higher alert

Birds living high in the mountains are better problem solvers and have more reliable memories than ones living lower down, according to research just published, writes Richard Collins.

Chickadees are the North America equivalents of the tits in Irish gardens. The mountain chickadee, a little grey and white acrobat, resembles our coal tit. It’s found from the Yukon to Mexico up to altitudes of 2,500m. A voracious eater, one found dead in Arizona, had 275 tiny caterpillars in its stomach. The nest is made in a hole behind the hard bark of a pine tree. It’s a particularly safe location; the female can afford to spend longer incubating than her cousin, the black-capped chickadee, which excavates a hole in softer wood.

Dovid Kozlovsky, and a team at the University of Nevada, caught 24 mountain chickadees in a Californian forest. Twelve of them were trapped at an altitude of 1,800m. The others came from 600m higher up. All were just a few months old, none having lived through a winter. The captives were taken to an aviary where their problem-solving skills were tested.