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Animal Noses
Nature Bulletin No. 729   October 26, 1963
Forest Preserve District of Cook County
Seymour Simon, President
Roberts Mann, Conservation Editor

ANIMAL NOSES
"Of all the animals, man has the poorest nose; he has virtually lost the sense of smell". Like so many general statements, that remark by Ernest Thompson Seton, the great naturalist, artist and storyteller, should be taken with a grain of salt. Seton was speaking of mammals only.

Modern man does have a sense of smell and in some individuals, such as wine tasters, coffee tasters and perfumers, it is highly developed but, in general, his nose is far inferior to the smellers of other mammals. Nearly all of them have noses which provide the most acute and discriminating of the five senses: smell, sight, hearing, touch and taste. Among the few exceptions are the toothed whales, believed to have no sense of smell at all.

There are other groups in the animal kingdom which apparently have no sense of smell comparable to that of mammals. The lower invertebrates have none. Birds, with few exceptions, have none. Contrary to popular belief, vultures find their prey -- dead animals -- by means of their marvelous telescopic vision and not by any ability to smell it. They commonly find carrion before it begins to rot and stink.

However, experiments have demonstrated that some seabirds -- petrels, shearwaters, and the albatross --do have a well-developed sense of smell; and that the kiwi, a queer humpbacked flightless bird in New Zealand, finds its prey at night by means of its acute senses of smell and hearing. There are slit-like sensitive nostrils near the end of the long bill.

Many insects notably moths, some butterflies, honeybees and ants -- have an extraordinary sense of smell. Lacking any nose, they have sensory organs located in the outer segments of their antennae or "feelers". We know of an instance when the scent of a female Cecropia moth, newly emerged from a cocoon in a cage within a greenhouse where a few windows were partially open, attracted scores of males -- some of them from miles away. Bees in search of nectar are attracted to flowers as much or more by their scent as by their color. Ants follow odor trails made by co-workers. They live in a world of smells.

Fish are commonly ranked among the supersmellers but most scientists agree that, instead, they are supertasters. As explained in Bulletin No. 270 (Smells and Smellers), smell and taste are closely related chemical senses but odors come as minute particles in gaseous form, whereas taste is a sensation produced by particles in a solution such as water. Some fish have sense organs located from mouth to tail, so that they literally taste with the whole body.

Having such poor noses ourselves and no other way of detecting or measuring odors, it is difficult for us to appreciate how important -- how vital -- an acute sense of smell is to most wild four-footed animals. By means of it they find their food, evade their enemies, find others of their kind and find mates. For deer, rabbits and other defenseless species it spells life or death. It enables an arctic hare to survive by finding the tops of dwarf willows beneath several feet of snow, or a squirrel to find acorns that he buried in autumn.

Much of what we know about animal noses has been learned by observers and hunters of wildlife; also from dogs bred and trained to trail and find certain kinds of game. A dog's sense of smell is as marvelous as that of a wolf or an elephant. A 'coon hound, for instance, knows when a raccoon's track was made, how fast it was traveling, and in what direction. He will ignore the scent of a rabbit or any other animal.

"Does it not betray itself by its odor?" (Cicero)


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