How roosters protect themselves from their own deafening crows
|sciencemag.org 19 ian. 2018 at 14:26|
A roosters crow is so loud, it can deafen you if you stand too close. So how do the birds keep their hearing? To find out, researchers attached recorders to the heads of three roosters, just below the base of their skulls. Crows lasted 1 to 2 seconds and averaged more than 130 decibels. Thats about the same intensity as standing 15 meters away from a jet taking off. One roosters crows reached more than 143 decibels, which is more like standing in the middle of an active aircraft carrier. The researchers then used a microcomputerized tomography scan to create a 3D x-ray image of the birds skulls. When a roosters beak is fully open, as it is when crowing, and soft tissue covers 50% of the eardrum, the team reports in a paper in press at
. This means roosters arent capable of hearing their own crows at full strength. The intensity of a roosters crow diminishes greatly with distance, so it probably doesnt cause significant hearing loss in nearby hens. But if it did, shed likely be OK. Unlike mammals, birds can quickly regenerate hair cells in the inner ear if they become damaged.