Do Birds Have a Sense of Smell

Copyright © Harry Nehls, Audubon Society of Portland Smell and Taste Play Important Role in Birds. For years ornithologists thought that birds had little or no sense of smell. It was hotly debated and many experiments were conducted to prove or disprove whether they could smell or not. The matter is still not settled, but modern data indicates that all birds have and use their sense of smell. Birds breathe through their nostrils, which leads the air into three internal nasal cavities (called concha). There the air is purified and warmed before moving on into the lungs. It is in these cavities that the olfactory organs are found. Some species have large conspicuous olfactory organs, and on others they're small and inconspicuous, but all seem to function to the needs of the bird. It has long been known that vultures, seabirds, and Kiwis have a strong sense of smell, but scientists generally regarded most other birds, especially the small land birds, as having no sense of smell at all. Recent studies have proven that even finches and sparrows have a sense of smell not unlike that of rats and mice. Experiments with Mallards have shown that when the female is ready to mate it releases pheromones in the oils that it uses to clean its feathers. Male Mallards become sexually active when they smell this odor. When the male sense of smell is impaired, sexual responses are severely reduced. Rather surprising, but perhaps should be expected, experiments have shown that the European Starling can smell certain plants that contain chemicals that can disinfect its nest of parasites, thus increasing successful fledging of young. The theory that a mother bird would reject its nest and young if handled by humans has long ago been disproved. If a bird is repulsed by the smell of humans it would be in real trouble. Humans and their smell are everywhere. The sense of taste in birds has proven to be a very difficult subject. It is hard to separate if taste, smell, or sight is most important in food selection. At one time it was believed that birds had no sense of taste at all, but that has changed. It has been found that birds have 50-100 taste buds depending on the species, in comparison mammals have up to 9,000. This enables humans and mammals to sense a wide variety of taste combinations. Birds on the other hand have a limited, but well-defined ability to sense select tastes that are most important to them. Unlike those of mammals, taste buds in birds are not found on the tongue, which is a hard bony tool, but in the soft tissues inside the mouth. Food passes quickly through the mouth so there is little time to evaluate the taste of what is picked up, but the birds receive enough information to identify the taste. While most birds avoid salty or mineral water, finches, pigeons and several other species seek out saltlicks and mineral springs. Finches and other birds that do not get needed minerals from the food they eat regularly pick up minerals from roadside gravel and other sources The sense of taste at that time is most important. One clue to the differences of taste between birds and mammals concern chili peppers and other spices. Birds relish hot spices and get considerable nourishment from them. On the other hand, spices repel most mammals. Recently squirrel-proof wild birdseed has come on the market. It is liberally mixed with chili pepper bits. After a few visits to the feeder the squirrels will not return, but the birds are even more attracted than before. Another promising product is on the market, a spray that makes grass taste bad to ducks and geese. This should reduce the complaints from golf course and city park managers. Other sprays repel birds from fruit trees and bushes. Although there is still quite a bit to learn on how birds use smell and taste in their lives, we have already found that both are very important, not always in ways humans and mammals use these senses, but in ways important to the birds. -- Harry Nehls, Audubon Society of Portland.