ASSESSMENT METHODS OF CORMORANT (Phalacrocorax carbo) DIET

Abstract

Various cormorant diet assessment methods are used to assess their daily meal in order to evaluate, using these and other data, the damage to commercial fish farms as well as the damage on open waters caused by cormorants. All of the parameters used for evaluating the damage to fish stock (number of birds, density and fish structure, daily meal, fish price, degree of protection and preservation etc.) are specific for an individual fishpond or other body of water and can only be used for that locality and not elsewhere. The results on the lowest and highest values of fish mass that cormorants eat daily vary extensively. By examining the available literature, the following values for individual adults have been determined: pellets — 347 g, pellets of captive cormorants — 371 g, stomach content — 359.5 g, regurgitations — 260 to 539 g, energy requirements — 751 g, stomach temperature — 336±98 g.

Keywords

• assessment methods
• diet
• cormorant
• phalacrocorax carbo