The effect of craniokinesis on the middle ear of domestic chickens (Gallus gallus domesticus)

• DOI: 10.1111/joa.12566
• Publication Date: 2016-11-29T08:54:49Z
• Authors: Raf Claes; Pieter G. G. Muys...; Luc Van Hoorebeke; Jelle Dhaene; Joris J. J. Dirckx; Peter Aerts
• Keywords: Quadrate bone; Malleus; Keel; Ossicles; Incus; Columella; Neurocranium

Abstract The avian middle ear differs from that of mammalians and contains a tympanic membrane, one ossicle (bony columella cartilaginous extra‐columella), some ligaments muscle. rim the eardrum (closing cavity) is connected to neurocranium and, by means broad ligament, otic process quadrate. Due limited number components in ear, possibilities attenuating conduction sound seem be activity stapedius We investigate what extent craniokinesis may impact because connection movable quadrate part beak suspension plays an important role craniokinesis. Micro‐computed tomography was used visualize morphology effect on domestic chicken ( Gallus gallus domesticus ). Both hens roosters are considered their difference vocalization capacity. It hypothesized effects, if present, will greater louder vocalization. Maximal lower jaw depression comparable for (respectively 34.1 ± 2.6° 32.7 2.5°). There no overlap ranges maximal upper elevation between sexes 12.7 2.5° 18.5 3.8°). Frontal rotation about transversal quadrato‐squamosal, inward squamosal‐mandibular axes were both 15.4 2.8° 11.1 These rotations did not affect columellar position or orientation. In hens, influence movements shape could detected either; however, caused slight stretching towards caudal roosters, displacement conical tip membrane 0.378 0.21 mm, as result craniokinesis, observed. This linked flattening slackening eardrum. changes most likely go along with deformation extra‐columella. Generally, birds, larger opening related intensity coupling lifting suggest presence passive attenuation mechanism during self‐vocalization.