Quail eggs are like fingerprints, a new study suggests. The creamy blue-and-brown speckled eggs, splashed like a toddler's art project, vary among birds but are consistently patterned for individuals.

For some birds, recognizing their own eggs can be a matter of life or death. In a new study, scientists have shown that many birds affected by the parasitic Common Cuckoo -- which lays its lethal ...