the siamang's calls and songs can be heard for over two miles. and what's the point of making such a fuss? communication, naturally. (screeching) siamangs sing to claim their territory and even engage in duets to call out that a mating pair lives there. (hooting) owls have territorial calls. (chirping) and so do songbirds. geese have contact calls for locating their mate. but this peacock is all about visual communication when it comes to impressing the peahens. in fact a lot of the communication happening in the animal world is about finding... (howling) (roaring) ...getting and keeping a mate. and that often means defending your territory. lions defend their territories by roaring. (roaring) and wolves defend their territories by howling. (howling) fireflies find mates by flashing their lights. greater prairie chickens attract females by displaying. and red-crowned cranes strengthen their bonds with a vocal duet. (hooting) you probably don't think of deer as being vocal. just to let their rivals know how tough they are. (roaring) it costs a lot