Do Birds Have a Sense of Smell?

While sight is arguably the most important sense wielded by birds, olfaction plays a critical role in their survival as well. It was only in the last 50 years that birds’ sense of smell was discovered. In the past, scientists believed that birds had little to no smelling ability, but studies have shown just how wrong previous hypotheses were.

An Overview of Bird Senses

Environmental setting seems to have dictated what senses become dominant as bird species evolve, although, similar to humans, senses can be honed when needed. Albatrosses, for example, can use scent to find prey across long distances, and switch to sight as their primary sense when closer to their food. Also, shearwaters can navigate using their sense of smell but trust their vision when deprived of olfactory cues. Certain species of birds rely predominantly on sight to survive while others monopolize their olfactory receptors. Generally, while sense of smell varies between species, birds rely more heavily on sight and hearing than their senses of touch and taste.

Sight

It is fitting that eyes take up more space in birds’ skulls than their brain does since sight is, in most cases, the most important sense. Species in the Aves class usually have extremely sharp eyesight, allowing them to spot predators, prey, and other birds from great heights and across long distances. Evolution played a part in maintaining smaller bird species, instilling them with the ability to see UV light, unlike predatory birds and humans. While birds of prey have frontal set eyes, other species have eyes set on the sides of their heads to keep watch from a wider range.

Hearing

Though sight usually dominates the other senses in Aves species, the auditory sense is also essential to birds’ survival. When you hear birds chirping, they are communicating information with each other. Birds use their sense of hearing to hunt for food, escape predators, and, in some species, locate their hatchlings. Birds’ hearing, just like their sight, is highly developed.

Birds With the Best Sense of Smell

Certain birds have developed extremely strong senses of smell after evolving to a habitat that prioritizes scent over sight.

Turkey Vultures

The turkey vulture is one of the best examples of a bird species that relies heavily on scent. They have developed their olfactory sense to locate food in environments with dense canopies of leaves. Vultures can pinpoint the scene of food without ever having to see it. You may have seen a small pack of vultures circling in the air while they wait to catch a new scent.

Kiwis

The national icon of New Zealand, kiwis are flightless birds with extremely long beaks considering its small size. They are the only birds known to have nostrils on the tip of its sensitive beak. Since they cannot fly, kiwis as a species have adapted to sniff out hidden food. They can sense a worm deep in the ground and grab it without even opening its beak. Despite its cultural significance in New Zealand, kiwis have been lost at a rate of 2% each year, and there are less than 70,000 left in the country.

Albatrosses, Shearwaters, and Petrels

The olfactory bulb in the brain controls a creature’s sense of smell. Albatrosses, shearwaters, and petrels — all procellariform seabirds — have some of the largest olfactory bulbs (compared to brain size) of any bird species. Their incredible navigational abilities are dependent on olfaction to locate themselves and the distances they have traveled. One study compared anosmic to non-anosmic shearwaters and found those that lacked their sense of smell took an alternate route during their flight home after foraging. The shearwaters deprived of smell used vision to make out topographic information, flying closer to the coastline compared to shearwaters with their olfactory sense. Albatrosses and petrels display a similar dependency on smell for navigational purposes over the open ocean. Moreover, petrels that forage at night can locate their burrows in the dark using scent. Olfaction also plays a part in foraging. Shearwaters can make out the odors of food such as squid and krill when feeding over the ocean.

Pigeons

A similar experiment to the shearwater study was conducted on pigeons in the 1970s. After depriving a group of pigeons of their sense of smell, researchers found that the birds could not find their way back home after getting released in different locations. By observing the pigeons that could and could not smell, researchers discovered that the birds track environmental smells based on wind direction and can distinguish familiar odors in the air to help locate their intended destination. Pigeons and seabirds alike can use the odor compounds in the atmosphere to navigate and locate themselves when in unfamiliar places.

Olfactory sensitivity has played a key part in maintaining the survival of some of the most well-known birds we have today. Despite these species existing for thousands of years, the significance of olfaction was only recently realized, shocking some ornithologists who previously understated avians’ sense of smell.