Great tits inherit egg spots from mom
By Susan Milius
After examining more than a thousand clutches of eggs, researchers at Oxford University in England say a female great tit inherits her eggshell pattern from her mother’s side of the family.
Just what determines eggshell patterns has perplexed researchers. Cuckoos, for example, have evolved female lineages that mimic egg patterns of other species. The cuckoos swoop into nests of the birds whose eggshells they can fake and leave an egg for the nest owners to rear.