European cuckoos lay very different eggs depending on the host species. Genetic analyses have revealed how this adaptation is inherited without leading to speciation. Bright blue, white, greenish, ...

Perhaps the most famous nest hijacker in the bird world, the common cuckoo has even given rise to the phrase “cuckooing.” A female cuckoo carefully watches her host bird, usually small songbirds like ...

Female lineages of European cuckoos lay eggs with colorful shells and intricate patterns specialized to deceive more than 100 avian hosts into fostering their chicks. Parasitic cuckoo eggshells show ...