Darwin’s finches have nothing on these chameleons

When it comes to eating hard-shelled bugs, the wildly varied species in the Bradypodion genus of dwarf chameleons have evolved an incredible array of a special part for doing the work: their heads. Scientists long wondered why these closely related South African lizards had such diverse noggins—some wide, some tall, and some covered with scaly head or chin frills. So they looked at the diets of 14 of the 17 known chameleon species, and compared them with the lizards’ head type. Researchers found the size and shape of a chameleon’s head matched its preferred diet, they report in Functional Ecology. For example, forest lizards with taller heads generally ate softer foods, including butterflies, dragonflies, and even other reptiles. Those with crestlike shapes on top were able to bite harder, ideal for eating larger insects. But the plains lizards—most of which lack crests—tend to have wider mouths, which help them crunch on smaller but harder beetlelike bugs, even without the attractive head feature. The chameleons living in South Africa’s Fynbos plains are also smaller than their forest-dwelling cousins, possibly as a result of having less food available. The comparatively colorful forest morphs are likely the ancestral version of the species, which evolved as Africa’s southern forests shrank.