THE speckles on birds’ eggshells not only make good camouflage, they could also stop them breaking under their mothers’ weight.
A study of eggs laid by great tits (Parus major) has concluded that the spots and speckles have a mechanical role, strengthening the eggshell at its weakest points and so compensating for a shortage of calcium in the mother’s diet. “For a hundred years, people assumed speckling was for camouflage,” says Andrew Gosler of the University of Oxford, whose team analysed patterning and composition of around 90 eggshells. They found that the spottiest eggs came from areas where soils…
