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The ground hornbills (Bucorvidae) are a family of the order Bucerotiformes, with a single genus ''Bucorvus'' and two extant species (though possibly including another genus with six extant species). The family is endemic to Sub-Saharan Africa: the Abyssinian ground hornbill occurs in a belt from Senegal east to Ethiopia, and the southern ground hornbill occurs in Southern and East Africa. Ground hornbills are large, with adults around a metre tall. Both species are ground-dwelling, unlike other hornbills, and feed on insects, snakes, other birds, amphibians and even tortoises.〔Kinnaird Margaret F. and O‘Brien< Timothy G.; ''The Ecology and Conservation of Asian Hornbills: Farmers of the Forest''; pp. 20-23. ISBN 0226437124〕 They are among the longest-lived of all birds,〔Wasser, D. E. and Sherman, P.W.; “Avian longevities and their interpretation under evolutionary theories of senescence” in ''Journal of Zoology'' 2 November 2009〕 and the larger southern species is possibly the slowest-breeding (triennially) and longest-lived of all birds.〔Skutch; Alexander Frank (author) and Gardner, Dana (illustrator) ''Helpers at birds' nests : a worldwide survey of cooperative breeding and related behavior'' pp. 69-71. Published 1987 by University of Iowa Press. ISBN 0877451508〕 ==Taxonomy== Ornithologists consider the hornbills a distinct order Bucerotiformes and usually raise the ground hornbills to family level (Bucorvidae) on account of their distinctness. The genus ''Bucorvus'' contains two extant species: * Abyssinian ground hornbill ''Bucorvus abyssinicus'' (also known as northern ground hornbill) * Southern ground hornbill ''Bucorvus leadbeateri'' A prehistoric ground hornbill, ''Bucorvus brailloni'', has been described from fossil bones in Morocco, suggesting that prior to Quaternary glaciations the genus was either much more widespread or differently distributed.〔Kemp, A. C. 1995 ''The Hornbills''. Oxford University Press, Oxford.〕 It is currently thought that the ground hornbills, along with ''Tockus'' and ''Tropicranus'', are almost exclusively carnivorous〔 and lack the gular pouch that allows other, less closely related hornbill genera to store fruit. Recent genetic data shows that ground hornbills form a clade with ''Bycanistes'', this clade being a sister taxon to the rest of the hornbill lineage.〔Woodruff, D. S. & Srikwan, S. 2011. Molecular genetics and the conservation of hornbills in fragmented landscapes. In Poonswad, P. (ed) The Asian Hornbills: Ecology and Conservation. National Center for Genetic Engineering and Biotechnology, Bangkok, pp. 257-264.〕 Bucorvidae are thought to represent an early African lineage, while the rest of Bucerotiformes evolved in Asia. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ground hornbill」の詳細全文を読む スポンサード リンク
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