?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? msafiri Sniffing it out As befits the owner of the world's most impressive nose, an elephant has an extraordinarily sensitive sense of smell. Watch a jumbo and you will see that it is constantly raising its trunk to the breeze, or using the tip to explore the ground and the bodies of its companions. This relentless olfactory questing mirrors the focus of its mind, be it on hidden food, impending danger or missing companions. The chemical information obtained is interpreted within the nasal cavity, where layers of sensitive tissue are packed with millions of receptor cells. This super hooter proves especially useful during breeding: one elephant can determine the sexual state of another by detecting hormones or chemical molecules in its urine, dung or glandular secretions. And if it cannot find out enough by simply sniffing, it will collect the substance on the tip of its trunk and lift it to the roof of the mouth, where a natty device known as Jacobson's organ completes the analysis before passing the message to its brain. Sounds of silence An owl, as you might guess from its big eyes, has powerful eyesight – about 100 times more powerful in darkness than our own, in fact. But, perhaps surprisingly, its most valuable sensory weapon is hearing. Most animals perceive the direction of a sound by sensing the time lag between its arrival in one ear relative to the other – a sound coming from the right, for instance, reaches the right ear before the left and the difference computes its direction. But in owls, one ear sits slightly lower on the head than the other. This unique arrangement serves to exaggerate the perceived time lag in the vertical as well as the horizontal plane, and enables an owl to pinpoint the source of a sound with amazing accuracy. An African grass owl ( Tyto capensis), for instance, can catch a mouse in complete darkness using hearing alone. The saucer- like ' facial discs' around an owl's eyes act like feathered satellite dishes, directing sound to the ears and ensuring that the slightest rustle of an unsuspecting rodent seals its fate. Sense & sensitivity African animals have evolved a battery of sensory adaptations with which to negotiate their surroundings. Mike Unwin explains Saucer- like ' facial discs' around this white- faced scops- owl's eyes act like feathered satellite dishes, directing sound to the ears 126 WILDLIFE Stretching? Simply not. Elephants use their impressive nose to sense danger, food or missing companions & An African gras owl can catch a mouse in darkness using hearing alone |