A revision of vulture feeding classification

Abstract

Pioneering fieldwork identified the existence of three feeding groups in vultures: gulpers, rippers and scrappers. Gulpers engulf soft tissue from carcasses and rippers tear off pieces of tough tissue (skin, tendons, muscle), whereas scrappers peck on small pieces of meat they find on and around carcasses. It has been shown that these feeding preferences are reflected in the anatomy of the skull and neck. Here, we demonstrate that these three feeding groups also emerge when body core and limb bones are added to the analysis. However, the resulting classification differs from that which is based on skull morphology for three species, namely Gypaetus barbatus (Linnaeus, 1758), Gypohierax angolensis (Gmelin, 1788) and Gyps indicus (Scopoli, 1786). The proposed classification would improve the interrelationship between form and feeding habits in vultures. Moreover, the results of this study reinforce the value of the categorisation system introduced by Kruuk (1967), and expanded by König (1974, 1983), Houston (1988) and Hertel (1994), as it would affect not only the skull morphology but the whole-body architecture.