Guest Blogger Fatbirder
Birds, as we all know, are fascinating creatures that come in a variety of shapes and sizes. From their stunning plumage to their graceful flight, birds are truly a sight to behold. However, one aspect of birds that is not as widely known as it should be is their incredible sense of hearing. Do birds have ears? The answer is of course they do, but they are different from human ears in a number of ways.
Birds have two types of ears: the external ear, known as the auricular opening, and the internal ear, also known as the cochlea.
Although a number of birds appear to have external prominent ears… such as the Long-eared Owl these feather tufts are unrelated to hearing and not part of the ear.
The auricular opening is located on either side of the head and is covered by feathers. It is the entrance to the internal ear and the only visible part of the bird’s auditory system. This opening is not as well developed as the ears of mammals, although it still plays an important role in bird hearing. Mammals often have prominent ears capable of funnelling sound into the internal ear. In bats, which rely on echo location these are relatively massive, in humans the fleshy outer ear works to channel sound into the outer ear so it can more easily impact on the ear drum and transmit sound though a complex mechanism to the brain.
The internal ear, also known as the cochlea, is the most important part of the bird’s auditory system and is similar in its function to cochleas in mammals. It is responsible for converting sound vibrations into electrical signals that are then sent to the brain for processing. The cochlea is a spiral-shaped structure that contains specialized cells known as hair cells. These hair cells are responsible for converting the sound vibrations into electrical signals and are the key to the bird’s ability to hear.
Birds have excellent hearing and are capable of detecting sounds that are inaudible to humans. This is because birds have a much wider range of hearing than humans, with some species capable of hearing sounds in the ultrasonic range. For example, bats use ultrasonic sounds to navigate and communicate, and birds are capable of detecting these sounds, which gives them an advantage in avoiding predators.
One of the reasons why birds have such good hearing is their ability to adjust the position of their ear openings. This is known as pinna movement, and it allows birds to direct their ears in the direction of a sound. This ability is especially important for birds that rely on their hearing to locate food or to avoid predators. For example, owls have highly directional hearing, which allows them to locate their prey even in complete darkness.
Another factor that contributes to birds’ hearing ability is the shape of their head. Birds have a large cranial cavity, which helps to amplify sounds. This is especially important for species that live in noisy environments, such as city birds, where they need to be able to hear each other over the noise of traffic and other urban sounds. Despite the many similarities between the auditory systems of birds and mammals, there are also some key differences. For example, the cochlea of birds is much simpler in structure than the cochlea of mammals. This difference in structure is thought to be related to the different types of sounds that birds and mammals are exposed to. Birds are more exposed to high-frequency sounds, such as bird calls and alarm calls, and their auditory system is optimised for detecting these sounds.
So, yes, birds do have ears and are capable of hearing sounds that are inaudible to humans. Their auditory system is optimised for detecting high-frequency sounds and is capable of directing their ears in the direction of a sound. This is important for many species of birds, as it helps them to locate food, avoid predators, and communicate with each other. While the auditory system of birds is different from that of mammals, it is still a crucial part of their biology and plays an important role in their survival.
Without ears there would be no point in making the wonderful calls and song that is so rife in the avian world. Calling or singing to deter rivals and establish territories, attract mates and warn of approaching danger is a vital attribute.