Birds engage in evolutionary arms race
Eggs of cuckoo finches and tawny-flanked prinias have grown more colorful in the last 40 years — a sign that the neighbors are locked in an evolutionary arms race.
African cuckoo finches (Anomalospiza imberbis) dump their eggs into the nests of tawny-flanked prinias (Prinia subflava). By laying eggs that mimic prinia clutches, cuckoo finches trick the prinia into caring for the finch young.
Over the last decades, both birds have evolved a greater diversity of egg colors: As prinias developed new hues to defend against invaders, cuckoo finches retaliated with new fakes, researchers from the University of Cambri