Birds have long been thought to have a poor sense of smell, but recent research has shown that some bird species do use their sense of smell extensively. In this article, we’ll take a look at which species have been shown to rely on their sense of smell and how they use it.
Do All Birds Have a Sense of Smell?
All birds have a sense of smell, but it varies greatly in how developed it is and how much they rely on it. Birds have proportionately smaller and simpler olfactory bulbs and nerves relative to mammals. However, some species, particularly vultures and tubenosed seabirds, have shown a very developed sense of smell.
How Do Birds Use Their Sense of Smell?
Birds use their sense of smell in the following ways:
- Finding food – scavengers like vultures use smell to locate carcasses from great distances.
- Navigation – some migratory birds may use smell cues to navigate on migration routes.
- Detection of predators – birds may be able to smell predators, alerting them to danger.
- Nest recognition – parents can identify chicks in the nest by smell.
- Foraging and food selection – seabirds may use smell to locate prey patches.
- Social communication – birds may relay information via scent such as alarm or territorial markers.
Which Bird Groups Have a Strong Sense of Smell?
Several groups of birds stand out for their well-developed sense of smell:
Vultures
Vultures have an excellent sense of smell to help them find food. Researchers estimate that Turkey Vultures have a sense of smell that is up to 1 million times better than humans. Other New World Vultures like the Black Vulture also have a highly refined sense of smell to detect carcasses.
Tubenosed Seabirds
This group of seabirds, including albatrosses, petrels, and shearwaters, have highly developed olfactory bulbs and nerves. They use smell extensively when foraging to detect dispersed food sources like krill patches or fish shoals across vast ocean distances.
Kiwis
The Kiwi bird of New Zealand is the only bird with highly developed olfactory lobes filling most of their skull cavity. They have a very refined sense of smell used to locate prey at night since they cannot see well. Kiwis probe the ground with their long beak relying on smell and touch to find food.
Parrots
Some studies indicate that parrots have a better sense of smell than previously thought. They appear to use scent to evaluate food, identify toxins, interact with their mate, and recognize their offspring in the nest.
Vultures, Tubenosed Seabirds, and Kiwis Rely Most on Smell
Among birds, vultures, tubenosed seabirds, and the Kiwi appear to have the most highly developed sense of smell. Their survival depends greatly on using their sense of smell to find food. They have the largest olfactory centers relative to their brain size of all birds studied.
What Specific Birds have a Good Sense of Smell?
Some specific bird species that are known to have a well-developed sense of smell include:
Bird Group | Bird Species |
---|---|
Vultures | Turkey Vulture, Black Vulture, King Vulture |
Tubenosed Seabirds | Albatrosses, Petrels, Shearwaters |
Kiwis | Brown Kiwi, Little Spotted Kiwi |
Parrots | Budgerigar, Cockatiel |
Raptors | Northern Goshawk |
Wading Birds | American Woodcock |
How do Birds Use Their Sense of Smell to Find Food?
Birds that rely heavily on their sense of smell have different techniques to locate food sources:
Vultures
Vultures soar high in the air and use smell to detect ethyl mercaptan, a gas produced by the decay of dead animals. They can detect the gas at concentrations of just a few parts per trillion. This allows them to spot and home in on carcasses from great distances.
Tubenosed Seabirds
Petrels and albatrosses use their sense of smell to detect dimethyl sulfide gas, an indicator of plankton and fish prey. They even have special nares (nostril slits) that help sample odor molecules from the air.
Kiwis
Kiwis bob their head up and down as they walk to waft odor molecules towards olfactory receptors in their nostrils. This allow them to smell subterranean invertebrates to probe for and capture with their long bills.
How Might Birds Use Smell for Navigation?
Some migratory bird groups like shearwaters and petrels may use smell-based cues to help them navigate on their long migrations. The mechanisms are not well understood but may involve sensing unique odor profiles from coastlines or productive oceanic areas that guide their route.
Smelling variations in odor plumes and moisture gradients across landscapes might also provide birds with a map sense during migration. However, more research is needed to determine how important smell-based navigation is compared to other cues like geomagnetic senses.
Conclusion
Smell is an important sense for some species of birds that use it to find food, navigate, identify threats, and communicate. Vultures, tubenosed seabirds, and kiwis show the most extensive olfactory capabilities among birds. However, for most bird groups besides these specialists, the sense of smell plays a relatively minor role compared to vision and hearing.
More research is underway to better understand how the chemical senses of birds work and their applications across different species. As our knowledge expands, we continue to uncover surprising new abilities in the avian world.