Short Communications Diet of the Imperial Cormorant Phalacrocorax atriceps at sub-Antarctic Marion Island

inshore foraging, diving seabird (Cooper 1985) distributed throughout the southern hemisphere south of 45's (Wat-son 1975). A brief description of the diet of the Imperial Cormorant at Marion Island has been published (Blankley 1981). We present here a more comprehensive report based on food sa...

Full description

Bibliographic Details
Main Authors: G. Espitalier-noel, N. J. Adams
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 1987
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.555.3397
Description
Summary:inshore foraging, diving seabird (Cooper 1985) distributed throughout the southern hemisphere south of 45's (Wat-son 1975). A brief description of the diet of the Imperial Cormorant at Marion Island has been published (Blankley 1981). We present here a more comprehensive report based on food samples collected throughout the year. Methods The study was conducted at Marion Island (46"52'S, 37'5 l'E), southern Indian Ocean, where there is an estimated population of 285 breeding pairs of imperial Cormorants (Williams er ul. 1979). Food sampling was carried out in all months from April 1984 to March 1985 inclusive. Roosting adults were caught on an oppor-tunistic basis and stomach-pumped using a water-offloading tech-nique (Wilson 1984). Stomach san~ples were immediately drained through a 0.5 mm sieve. At the laboratory. drained samples were weighed and sorted into major prey components, which were then weighed individually. Otoliths were removed from fish brain cases for subsequent measurement and identification. Loose fish otoliths and cephalopod beaks were separated from soft material by sort-ing under water. In addition, fresh regurgitation casts were col-lected at colonies in October and November during the breeding