Female adult Common Cuckoos appear in two color morphs, shown here as half of the rufous (hepatic) form (left) and half of the gray morph (male-like, right). Several species of cuckoos, a genus of ...

Two new studies into lizard colors reveal how one species maintains its colorful diversity while others are losing their ...

Common cuckoo (Cuculus canorus) in flight. This is an adult male: Grey morph adult females have a pinkish-buff or buff background to the barring and the sides of the neck, and sometimes small rufous ...