Winter robins seeing red.

• Position: Your Life - Brief article

Red breasted robins are a classic symbol of the winter months and have adorned Christmas cards for more than a century. Ornithologists studying the feathers of Erithacus rubecula have discovered that the red breast reveals more than simply the species of the owner. The findings demonstrate how the famous red breast varies in size and coloration over ages and sexes, suggesting it may be used to communicate features of the owner to other robins.

The research, led by Roger Jovano from the Spanish National Research Council, Seville, follows in the footsteps of renowned ornithologist David Lack, who studied the behavior of robins in the 1940s. Lack recorded that a violent hen robin attacked a headless stuffed specimen, leading him to discover that it was the red breast which triggered the aggression.

The contemporary team's results revealed unknown patterns of variation in the red breast and gray fringe of the bird. The size...