Comparative Gross Morphological Studies on the Lower Jaw (Mandible) of Cattle Egret (Bubulcus ibis), Jungle Babbler (Turdoides striata), Yellow-footed Green Pigeon (Treron phoenicoptera), Barn Owl (Tyto alba) and Shikra (Accipiter badius)

Abstract

The present study was conducted on lower jaw (mandible) of five avian species 14 having different feeding habit (Cattle Egret, Yellow-footed Green Pigeon, Jungle Babbler, 15 and Raptor birds like Barn Owl and Shikra) with an aim to compare gross morphological 16 features of the mandible. Two specimens of each species were collected from the naturally 17 died birds, in Nagpur region and processed by simple maceration technique. The present 18 study revealed that the mandible of above avian species was formed by the fusion of seven 19 bones i.e. Os mentomandibulare, Os dentale, Os spleniale, Os supra-angulare, Os angular, Os 20 articulare and Os prearticulare. Dentary symphysis sulcus or Os mentomandibulare was 21 dorso-medially wider in Raptor birds than the Cattle Egret, Yellow-footed Green Pigeon and 22 Jungle Babbler. The prominent mylohyoid line was found on its medial aspect and a small 23 rostral mandibular fenestra was on the lateral aspect of the Os spleniale in Cattle Egret. Two 24 large caudal mandibular foramina were found on the lateral aspect of rami of the mandible in 25 Barn owl and Jungle Babbler. In Yellow-footed Green Pigeon, Raptor birds and Jungle 26 Babbler, medial mandibular process was well defined and prominent while this process was 27 inconspicuous in Cattle Egret and Yellow-footed Green Pigeon. Yellow-footed Green Pigeon 28 and Jungle Blabbler had maximum ventrally curved angulus mandibulae in comparison with 29 other birds under the study. Mandibular rami were found to bow outwards in order to enlarge 30 gap between them, and mostly seen in the Raptors. The modification of lower jaw of Raptors 31 may be ascribed to their feeding habits. Mandible of the Cattle Egret and Jungle Babbler had 2 32 narrow and V-shaped dentary symphysis sulcus, it may be because of their eating and 33 probing habit of insects, pests etc.