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Les particularités morphofonctionnelles des appareils du bec et hyoïdien chez les touracos (Aves, Musophagidae) : relations avec la frugivorie

Les particularités morphofonctionnelles des appareils du bec et hyoïdien chez les touracos (Aves, Musophagidae) : relations avec la frugivorie

Authors :
Léonide P Korzoun
Christian Érard
Jean-Pierre Gasc
Source :
Comptes Rendus de l'Académie des Sciences - Series III - Sciences de la Vie. 324:965-977
Publication Year :
2001
Publisher :
Elsevier BV, 2001.

Abstract

The present study points to morpho-anatomical features that allow vegetarian but mainly frugivorous turacos to fill at best their specific feeding requirements. Mechanisms are analysed which the bird can use to detach a fruit and avoid it rolls out of the bill. It is also examined how vegetable items can be processed particularly when they have to be cut, and what can facilitate their ingestion particularly when they are fruits that have to be swallowed entirely and are large and/or have dry or fibrous skin or flesh. The skeletal and muscular anatomy of the bill and hyoid apparatus is described in details and illustrated. The particularly short and stout bill coupled with a relatively simple system of aponevroses of the adductors reflects a trade-off between two important jaw functional requirements: huge efforts for clamping, and a wide opening for plucking, processing and swallowing relatively large fruit. The clearly oblique orientation of the modified outer adductor seems an adaptation to the detachment of fruits. The os uncinatum , particularly developed in this bird family, is interpreted as maintaining transversal stability, particularly when jaws act as a pair of scissors. Most food items being processed near the base of the bill, mechanisms have been developed which contribute to overcome the risk of breakage at the level of the prokinetic hinge because of a vertically oriented force there. Hyoid apparatus features are related to the tongue role during the detachment of the fruit and its processing in the bill.

Details

ISSN :
07644469
Volume :
324
Database :
OpenAIRE
Journal :
Comptes Rendus de l'Académie des Sciences - Series III - Sciences de la Vie
Accession number :
edsair.doi...........344457e888edf0a668ed5471d3e2eab7
Full Text :
https://doi.org/10.1016/s0764-4469(01)01363-4