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The Desertas petrel (''Pterodroma deserta'') is a small seabird in the gadfly petrel genus which breeds on Bugio Island in the Desertas off Madeira. The gadfly petrels in the genus ''Pterodroma'' are seabirds of temperate and tropical oceans. Many are little-known, and their often similar appearance have caused the taxonomy of the group to be rather fluid. Although the systematics on this species has not yet been definitively established, provisionally some authorities have split the Desertas petrel, separating the Desertas breeding birds from those in the Cape Verde archipelago, while others consider it a subspecies of the Fea's petrel. The species is named after its breeding grounds, which are pronounced "Dez-ERT-ass". ==Description== As all three of the species in the ''Pterodroma feae/madeira/desertae'' complex were once believed to be subspecies of a single species: ''Pterodroma mollis'', the extreme difficulty in telling them apart is easily understood. A summary of data from a morphological study sheds light on the issue: * In overall size ''feae'' is closer to ''deserta'' and both are bigger than ''madeira'' (wing length - ''f'':262, ''d'': 264, ''m'': 248; tarsus - ''f'':34.7, ''d'': 35.2, ''m'': 32.7). * Bill length once again similar in ''feae'' and ''deserta'' and both larger than ''madeira'' (''f'':29.0, ''d'': 28.6, ''m'': 26.3). * Bill depth by far biggest in ''deserta'', lowest in ''madeira'', and intermediate in ''feae'' (''f'':11.9, ''d'': 12.9, ''m'': 10.5). In terms of ratios: * (Bill length/wing length) (''f'':11.1%, ''d'': 10.8%, ''m'': 10.6%) is rather similar in the three taxa. * (Bill length/bill depth) (''f'': 2.44, ''d'': 2.22, ''m'': 2.53) is lowest in ''deserta'', and highest in ''madeira''. In ''feae'' it is intermediate, but more than twice closer to ''madeira'' than to ''deserta''. 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「Desertas petrel」の詳細全文を読む スポンサード リンク
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