For many years, scientific literature claimed that birds couldn’t smell or didn’t rely on their sense of smell for any purpose. However, research over the past few decades has proven that this claim is entirely false. Multiple studies show the fascinating and varied ways birds rely on smell for survival. Some bird species can even smell better than humans!

Before explaining the studies that changed the answer to the question, “Can birds smell?” let’s discuss why it was previously believed that birds couldn’t smell. From there, we’ll uncover how species such as turkey vultures, dark-eyed juncos, seabirds, and others use their olfactory sense to survive.
Why Science Believed Birds Couldn’t Smell
In John James Audubon’s notes on turkey vultures, he states, “The experiments instituted upon Vultures show that not only are they not led to their prey by the sense of smell, but also that they are not made sensible by it of the presence of food when in their immediate proximity.”

The experiments Audubon mentioned took place in the 1820s. He hypothesized that turkey vultures relied on their eyesight, rather than their sense of smell, to find carrion. He conducted two experiments to test this hypothesis.

In one of the experiments, he stuffed a deer skin with grass and left it out in the open with its legs up. Turkey vultures came to the deer and ripped it open, only to fly away once they realized there was only useless grass.
In another experiment, Audubon placed a rotting pig carcass in a ravine and covered it with foliage and brush. No turkey vultures came down to the carcass.
From these results, Audubon concluded that turkey vultures did not use smell to find food. This finding significantly influenced scientific literature, so much so that it became a popular belief that birds couldn’t smell or didn’t rely on smell.
The Evidence That Finally Said Yes to Can Birds Smell
There have been many pioneers who dedicated years of research and field study to finding an answer to the question, “Can birds smell?” They weren’t content with the original findings. Although Audubon thought them to be fully conclusive, many scientists didn’t agree—and with good reason. Now, we have genetic evidence and field study reports that undoubtedly support the fact that birds can smell.
Birds Have Olfactory Receptors
To be clear, most early biologists and ornithologists didn’t believe birds couldnot smell at all. Rather, they believed birds only had a rudimentary sense of smell and relied on their other senses for survival. After all, birds still have an olfactory system, which consists of the nose and nasal cavities. They also have an olfactory bulb, which is the brain’s smell center.
Research shows that within a bird’s olfactory system are olfactory receptors: proteins in the nasal passages that attach to odor molecules and translate the smell to the brain. Early scientists believed that these receptors were few and possibly mutated or nonfunctional.
Some Birds Have More Olfactory Receptors Than Even Humans
However, further research on several bird species showed that they contain several (at least a hundred or more) active olfactory receptors. For comparison, humans have about 100-200 functional receptors. A recent study compared the genomes of a hummingbird, emu, chicken, manakin, and zebra finch. The study found that these birds contained the following numbers of functional olfactory receptors:
- Hummingbird: 109
- Emu: 296
- Chicken: 355
- Manakin: 117
- Zebra Finch: 69

This means that these birds, especially the emu and chicken, have diverse scent receptors that allow them to pick up on a variety of smells. These birds were chosen for the study because they have “multiple publicly available genome assemblies on GenBank.”
According to the study, “These five species are representative across the three major groupings of extant birds [bird species that are alive and not extinct], including the Paleognathae and two groups within the Neognathae, Galloanseres, and Neoaves, represent diverse ecology, and include two important avian models, chicken and zebra finch.” As such, they represent other related bird species, giving biologists an idea of how many receptors each bird species might have based on these findings.
Field studies on various bird species have confirmed the genetic findings above and have added compelling evidence that says “yes” to the question: Can birds smell? In fact, they do it quite well.
New Evidence Challenged the Original Turkey Vulture Smell Experiment
Let’s go back to the turkey vulture experiments that started the whole controversial question: can birds smell? In 1960, ornithologist Kenneth Stager proved that Audubon’s original findings were inconclusive. Stager discovered that turkey vultures only feed from a carcass within a specific timeframe. They prefer it to be fresh and won’t go to a carcass after about four days.
Given that Audubon’s experiment used a rotting carcass, it’s likely the carcass was too far gone even for the turkey vultures. Furthermore, Stager proved that turkey vultures can smell and identified the specific scent they are attracted to: ethyl mercaptan.
Freshly decaying carcasses emit ethyl mercaptan. This compound also happens to be added to natural gas so that we can smell it when there’s a leak. Because of this, natural gas engineers have even followed vultures to areas where there are leaks in gas pipelines.
Further Experiments Addressed Whether Other Birds Can Smell
Turkey vultures aren’t the only birds that rely on smell to sniff out their next meal. Researcher Gabrielle Nevitt proved that Antarctic seabirds, such as shearwaters, albatrosses, and petrels, rely on smell to find food.


In her experiments, she dipped tampons (of all things) in pungent compounds found in marine fish and krill and hung them on kites to see if any of the above birds would come swooping in. They did.
So many came that she brought the kites down in fear that the birds would get tangled in them. She also dropped vegetable oil mixed with the fishy compound into the water and found that the birds flocked to the oil.
Nevitt went on to further prove that tube-nosed seabirds use smell to find food. She honed in on the specific scent they track: dimethyl sulfide (DMS). This gas is emitted by phytoplankton when krill feed on the microscopic plants. Krill are a major food source for these birds. Through various experiments, she found that tube-nosed seabirds could detect the smell of DMS and track it over miles of open water.
Poor-sighted Birds Rely on Their Sense of Smell
ides seabirds, other birds rely on their sense of smell, rather than their eyesight, to find food. One of the earliest leading researchers on birds’ olfactory senses, Bernice Wenzel, discovered that the New Zealand kiwi relied on smell to find earthworms and other invertebrates.
Kiwis are flightless, nocturnal birds with poor eyesight. They are the only bird species to have their nostrils at the end of their long beak, which sways back and forth above the ground to pick up scents. Based on genetic findings, kiwis have one of the largest olfactory bulb sizes in birds and about 600 olfactory genes.

Another example is the European white stork, which is attracted to the smell of freshly mowed grass. This species has learned that when grass is cut, they are more likely to find exposed insect and rodent prey. Researcher Martin Wikelski and his colleagues proved this by spraying the smell of cut grass over an unmowed field. Sure enough, the storks came to forage, even though the field hadn’t been mowed.
These are just a few examples (of many) that show how diverse bird species rely on smell to find food. However, sniffing out food isn’t the only way birds rely on their sense of smell to survive.
Other Ways Birds Rely on Scent
Research shows that a bird’s sense of smell correlates to the size of the olfactory bulb in their brain. Based on this, it’s easy to assume that small birds, such as dark-eyed juncos, who have tiny bulbs, don’t rely on smell as much. However, professor and researcher Danielle Whittaker discovered that juncos relied on smell, rather than visual cues, for reproduction.
Mating, Escaping Predators & Dodging Parasites
Juncos have a gland at the base of their tail that secretes what is known as “preen oil.” They use this oil to protect their feathers, but it also has a scent. Whittaker found that juncos had individual scents, which allowed them to be distinguishable in their flock. She found that females were attracted to a male’s scent more than to visual factors. She also discovered that juncos with strong “male-like” or “female-like” scents had more success raising their young to fledging.

Even though juncos have a small olfactory bulb and subsequently fewer scent receptors, these small sparrows significantly rely on smell for their social and reproductive life. Similarly, the Eurasian blue tit and European starling can detect aromatic plants, such as mint or milfoil. These birds weave these plants into their nests for two reasons: one, the scent seems to play a part in attracting the female: and second, these aromatic plants repel parasites.
Furthermore, the blue tit won’t enter its nest if it smells weasels. It can also find prey by smelling the volatile chemicals emitted by pine trees when they are attacked by insects.
The crested auklet, a seabird found on St. Lawrence Island in the Bering Sea, smells like tangerines. Scientist Julie Hagelin found that these birds start producing this scent in early spring, and it wears off over the summer. Females are attracted to strong-scented males, and she says, “the scent could function as a kind of ‘olfactory ornament,”. This is similar to how male birds adorn bright feather colors in spring to attract a mate.
Some Birds Use Smell To Find Their Way Home
Apart from reproduction and foraging, birds rely on scent to find their favorite roosting spots or burrows. Burrowing birds, such as the diving petrel, can distinguish their burrow among many others based on the scent. The rock dove, or pigeon, can find its way back to its roosting site using smell alone and can even find its way back over 1,000 miles.
Can Birds Smell?

Nowadays, there’s no doubt about whether birds can smell or not—they most certainly can. So the next time someone asks you, “Can birds smell?” I hope you answer with an enthusiastic, “Yes!”
Perhaps you’ll tell them about the unassuming dark-eyed juncos who choose their mate by scent. Or the mighty albatross, who flies over the open sea, tracking their prey by the smell of DMS. Maybe you’ll tell them about the turkey vulture, and how the famous John James Audubon got it all wrong. No matter what part of the research you tell them, just make sure they know birds definitely can smell.