Bird Ears Anatomy and Hearing Mechanism

Most of the birds make a chirping type of noise. This is probably one of the most definitive characteristics that they have. Sounds in the birds can act as a prelude to courtship calls, communication for assistance, or identification. Birds also tend to use these sounds to convey the message of approaching danger. So, since the birds are using sound as a means of communication, it is pretty natural that these organisms have bird ears and they are able to hear the sounds that are created. In fact, bird ears have also been proved to have a role to play in providing balance to the birds. 

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Bird Ears Anatomy: The Structure of Bird Ears

• The bird ears are not really the same as the human ears. Birds don’t have any external ear lobes like humans or dogs. They just have a small folded flesh that is hidden under the feathers. There is just an opening, some internal parts, and the tube that connects the opening to the parts of the birds’ ears. When seen from outside, one might not be able to figure out the presence of the ears since they are always under the feathers. There are three chambers in the birds’ ears. The outer ear can be seen as a tube that leads to the eardrum or the tympanum through the bird ear holes. There is a double membrane situated on the interior and it is a bit convex-shaped on the external section. The middle ear exists behind it and there is a single bone present there. The name of the bone is columella. The columella is connected to the eardrum by certain cartilaginous ligaments. While the middle and outer air has air, the inner ear has fluid in them. There are five parts in the inner ear of the bird. Two of them are the utriculus and semicircular canals that are connected to provide balance. The other three are known as lagena, sacculus, and cochlea. According to bird ears anatomy, the feather covering is provided in order to ensure that the ears of the bird are protected from the turbulence in the air when they are inflight. These feathers also have a very important role in ensuring that the dust and water in the atmosphere are kept away from the ears of the bird. The complete absence of barbs means these feathers don’t pose any obstructions when it comes to transporting the sound into the ears of the bird. The bird ears as well as the associated openings of the ears are located right below and slightly behind the eyes of the bird. 

What Sounds can they Hear? 

Within the different sounds, the ears of many birds are able to remember and recognize something related to the absolute pitch. Humans, on the other hand, tend to perceive the sounds with the help of relative pitch. However, there are rare humans who can remember and hear the absolute pitch. Due to relative pitch, humans can hear the sounds in octaves and recognize the tune in another octave. Birds don’t have that ability. They can recognize the ‘timbre’ in the noises though. The ability to recognize the harmonic variations provides the birds with versatility when it comes to responding to these sounds. 

The Bird ear holes are also capable of hearing shorter notes when compared to humans. While human beings are able to process the sounds in bytes that are limited up to 1/20^th of a second, the birds are capable of doing the same up to 1/200^th of a second. This would mean that while humans can hear just one sound, birds can hear 10 separate notes at the same time. For instance, pigeons are capable of hearing lower sounds. Some studies have claimed that pigeons can distinguish the music between Stravinsky and Bach. 

Sensitivity of Hearing in Birds

It is seen that some birds tend to have a hearing that can be much more sensitive than humans. For example, owls tend to be more sensitive to smaller sounds. Not just that, but owls also tend to have asymmetrical ears. One of the owl’s ears is in a lower position beside the skull than the other. Hence, the sounds that come from a particular source in the ears of the bird will be slightly different at different times. So, owls tend to have binocular hearing ability. This means they are able to pinpoint the location and source of a sound very easily. Another important thing to keep in mind about bird ears is that the head shape of the bird also has an important role in deciding the hearing capabilities of the birds. 

Conclusion

Through the article, it can be concluded that birds do in fact, have ears and can hear properly. Some birds have a higher sensitivity to hearing such as owls. Some birds even have properties of echolocation. Apart from that, birds start the process of hearing even before they have hatched. So, there are multiple uses of bird ears. Even though these ears are hidden behind the feathers of the bird, these organs prove to be very useful.