Low frequency specialization in the inner ear of the Ruffed Grouse (Bonasa umbellus).

Abstract

Event Abstract Back to Event Low frequency specialization in the inner ear of the Ruffed Grouse (Bonasa umbellus). Jeremy R. Corfield1* and Andrew N. Iwaniuk1 1 The University of Lethbridge, Neuroscience, Canada Male ruffed grouse use their wings to produce a unique non-vocal auditory signal to attract females and defend a territory. This ‘drumming’ behavior consists of a male perching on a log and beating its wings rapidly to produce a low frequency (< 100Hz) sound. This is the primary auditory signal produced by the ruffed grouse and unlike all other grouse and related galliform species, the ruffed grouse has an extremely small vocal repertoire and do not incorporate vocalizations into their courtship display. Hearing lower frequencies likely requires specialization to the peripheral auditory system and we therefore predicted that ruffed grouse would differ in this respect from other galliforms. Because there is a well established correlation between morphology and physiology in the avian inner ear, we examined the auditory nerve, basilar papilla and hair cells in the ruffed grouse to identify specializations that could be associated with low frequency hearing. The ruffed grouse papilla was approximately 4.6 mm long and showed the typically avian, moderate curvature and tapered width. The total hair-cell count was about 9,200, which is similar to that of the comparably sized pigeon. The mechanosensitive stereovilli bundles of the hair cells showed the typical change from tall bundles with few stereovilli to short bundles with many stereovilli along the apical-to-basal tonotopic axis. In contrast to most birds, however, within the apical, low frequency part of the basilar papilla the stereovilli height remained reasonably consistent. The number of afferent fibers in the ruffed grouse auditory nerve was lower than most other birds that have been examined, with only around 6,200 fibers. An estimate of the average innervation density showed that the afferent innervation ratio in the ruffed grouse was 0.74, suggesting that for every hair cell there are 0.74 nerve fibers. This ratio is at the lower end of birds and is similar to that of the emu and pigeon, both of which have low frequency vocalizations. On the ruffed grouse papilla, hair cell shape changed gradually from a tall and thin type (THC) to a shorter and wider type (SHC), both from apex to base and, at the same longitudinal position, from neural to abneural, which is typical of other birds. However, the ruffed grouse had few hair cells that meet the conventional criterion for short hair cells. Overall, the inner ear of the ruffed grouse has some features that are typical of most birds and other features that it shares with the emu and pigeon, species known to have low frequency specializations to their inner ear associated with the low frequency vocalizations. Keywords: Basilar papilla, Hair cell, Inner ear, Ruffed grouse Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for Participant Symposium) Topic: Sensory: Audition Citation: Corfield JR and Iwaniuk AN (2012). Low frequency specialization in the inner ear of the Ruffed Grouse (Bonasa umbellus).. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00189 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Jeremy R Corfield, The University of Lethbridge, Neuroscience, Lethbridge, Alberta, T1K 3M4, Canada, jr.corfield@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jeremy R Corfield Andrew N Iwaniuk Google Jeremy R Corfield Andrew N Iwaniuk Google Scholar Jeremy R Corfield Andrew N Iwaniuk PubMed Jeremy R Corfield Andrew N Iwaniuk Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.