Members of the cat family (Felidae) are nearly all lone creatures and use meows and roars to communicate to potential mates over long distances. (Lions are the exceptions; they're the only social kitty species.) Scientists have wondered why some calls are high pitched—like your housecat's meow—or deeper, like a cheetah's. Size would be the obvious answer, and research until now has shown that larger cats tend to have lower pitched calls. But a new study in the Biological Journal of the Linnean Society says that it's habitat that matters more.
Gustav Peters and Marcell Peters, of the Zoological Research Museum in Bonn, Germany, examined the relationship between call frequency, a cat's habitat and its place in the evolution of cats. The researchers found that cats that lived in open habitats like the African plains tended to communicate with deep-sounding calls. Kitties that lived in forested habitats, such as clouded leopards, produced high-pitched calls.
Their finding was unexpected because "most studies of sound transmission of animal acoustic signals found that lower frequencies prevail in dense habitats," Peters told the BBC. High-frequency sounds can more easily become disrupted by the vegetation found in forests while low-frequency sounds travel less well in open spaces where they can be disrupted by air turbulence. Why cat calls seem to have evolved in such a contrary way will have to be the subject of further study.
(And if you've ever wondered why only lions, tigers, jaguars and leopards can roar, here's why: Only those four species have an elastic ligament connecting bones that support the larynx in the throat. That ligament is necessary to produce a roar.)