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Article Dans Une Revue Marine Biology Année : 2006

Do cormorants injure fish without eating them ? An underwater video study

M. Boudiffa
  • Fonction : Auteur
He Liu
  • Fonction : Auteur

Résumé

The populations of European great cormorants (Phalacrocorax carbo) and North American double-crested cormorants (Phalacrocorax auritus) have increased sharply over the last decades and these piscivorous birds are suspected to deplete valuable fish stocks and compete with human fisheries. Beyond direct consumption of fish, cormorants are accused of injuring vast numbers of prey without eating them. Using underwater video systems, one of them mounted onto the back of tame Chinese cormorants, we evaluated the proportion of successful pursuits of cormorants on live fish. Trials were conducted with 6 great cormorants and 9 double-crested cormorants and involved a total of 676 prey pursuits. We show that, although they are regarded as highly efficient predators, cormorants aborted about half of their pursuits. However, detailed analysis of prey-capture behaviour in double-crested cormorants revealed that only 0.4% of the prey pursued was injured without being ingested. Further studies using miniature video systems deployed on free-ranging cormorants are required tocomplement our knowledge of their hunting tactics.

Dates et versions

hal-00110936 , version 1 (02-11-2006)

Identifiants

Citer

D. Grémillet, M.R. Enstipp, M. Boudiffa, He Liu. Do cormorants injure fish without eating them ? An underwater video study. Marine Biology, 2006, 148, pp.1081-1087. ⟨10.1007/s00227-005-0130-2⟩. ⟨hal-00110936⟩
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