Mountain Chickadee |
These energetic half-ounce birds hide thousands of food items every fall and rely on these hidden stores to get through harsh winters in the mountains of the West. To find these caches, chickadees use highly specialized spatial memory abilities. Although the genetic basis for spatial memory has been shown for humans and other mammals, direct evidence of that connection has never before been identified in birds.
Their research, “The Genetic Basis of Spatial Cognitive Variation in a Food-Caching Bird,” published Nov. 3 in the journal Current Biology. The research is a collaboration among scientists from the Cornell Lab of Ornithology; the University of Colorado, Boulder; the University of Nevada, Reno; and the University of Oklahoma.
“We all use spatial memory to navigate our environment,” said lead author Carrie Branch, a postdoctoral researcher at the Cornell Lab of Ornithology. “Without memory there’s no learning and an organism would have to start from scratch for every task. So, it really is life and death for these birds to be able to remember where they stashed their food. We’ve been able to show that natural selection is shaping their ability to remember locations.”
If natural selection (survival of the fittest) is shaping chickadee memory, certain criteria have to be met. There has to be variation in the trait: Some chickadees are indeed better than others at re-finding their stores. There has to be a fitness advantage: Birds that perform better on a spatial memory task are more likely to survive and produce offspring. Importantly, variation in the trait must have a genetic basis.