One would think sight and hearing would be the most acute of senses for birds, but research has shown that their sense of smell is pretty good too. Until recently, scientists thought the sense of smell in birds was not very good. But this has been turned on its ear so to speak.

Some bird species use their sense of smell to navigate, forage or even to distinguish individuals. Scientists studied what is called the Olifactory receptor genes. These are the genes that would dictate sense of smell. The total number of Olifactory receptor genes a bird has, is thought to determine how many scents they can smell.

Nine different species of birds were studied and there was a wide gap in between the different types of species. For example the canary has much less Olfactory receptors than that of the brown Kiwi from New Zealand. This was not surprising to the researchers as this varies greatly between mammals in general.

If you have never heard of the Kiwi, it is a small fury, looking brown bird with a long beak. The nostrils are at the end of the beak and it uses its sense of smell to guide it at night when it forages for food.

Some birds even use their sense of smell to detect whether or not a predator is nearby. Many birds that nest in holes, use this sense of smell to detect whether predators are approaching. This is very necessary as there is limited visibility inside the nest holes.

Evidence even goes as far back as in dinosaurs which are thought to have had Olifactory receptors (OR as the are commonly referred to) that were used in their hunting as well. And birds are thought to have evolved from the dinosaurs. There is evidence to support a distant relation of the two.

It is interesting to note that just because mammals have OR genes doesn't mean they use all of them. For example, humans only use about 40 percent of our OR genes and thus we have a poor sense of smell. But it was found that birds use the majority of their OR genes indicating that they have a good sense of smell.