Abstract
Sexual differences in the diet of king cormorants,Phalacrocorax albiventer, were investigated during the 1993/1994 austral summer at Macquarie Island. The major food items, identified by otoliths in regurgitations, were demersal fish; fish mass consumed could be estimated using a wet mass-otolith length relationship. Two fish species,Paranotothenia magellanica andHarpagifer georgianus, constituted 98% of the wet mass (male and female cormorants combined). Estimated individual fish mass ofParanotothenia magellanica (19.6±11.6 g) was greater than that ofH. georgianus (2.8±1.3 g). Total wet mass of food and number of fish in regurgitations did not differ statistically between the sexes of cormorants. However, males tended to feed on larger fish than did females.
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References
Bernstein NP, Maxson SJ (1984) Sexually distinct daily activity patterns of blue-eyed shags in Antarctica. Condor 86:151–156
Birt VL, Birt TP, Goulet D, Cairns DK, Montevecchi WA (1987) Ashmole's halo: direct evidence for prey depletion by a seabird. Mar Ecol Prog Ser 40: 205–208
Brothers NP (1985) Breeding biology, diet and morphometrics of the king shag,Phalacrocorax albiventer purpurascens, at Macquarie Island. Aust Wildl Res 12:81–94
Burger AE (1991) Maximum diving depths and underwater foraging in alcids and penguins. In: Montevecchi WA, Gaston AJ (eds) Studies of high-latitude seabirds. 1. Behavioral, energetic and oceanographic aspects of seabird feeding ecology. Can Wildl Serv Occas Pap No 68:9–15
Cooper J (1986) Diving patterns of cormorants Phalacrocoracidae. Ibis 128:562–570
Fairbairn J, Shine R (1993) Patterns of sexual size dimorphism in seabirds of the Southern Hemisphere. Oikos 68:139–145
Green K, Williams R, Slip DJ (1990) Diet of the Macquarie Island cormorantPhalacrocorax atriceps purpurascens. Corella 14:53–55
Harris MP, Wanless S (1993) The diet of shags during the chick-rearing period assessed by three methods. Bird Study 40:135–139
Hecht T (1987) A guide to the otoliths of Southern Ocean fishes. S Afr J Antarct Res 17: 1–87
Hecht T, Cooper J (1986) Length/mass relationships, energetic content and the otoliths of Antarctic codParanotothenia magellanica (Nototheniidae: Pisces) at sub-Antarctic Marion Island. S Afr J Zool 21:294–296
Johnstone IG, Harris MP, Wanless S, Graves JA (1990) The usefulness of pellets for assessing the diet of adult shagsPhalacrocorax aristotelis. Bird Study 37:5–11
Wanless S, Harris MP, Morris JA (1992) Diving behaviour and diet of the blue-eyed shag at South Georgia. Polar Biol 12:713–719
Williams R, McEldowney A (1990) A guide to the fish otoliths from waters off the Australian Antarctic Territory, Heard and Macquarie Islands. ANARE Res Notes 75:1–173
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Kato, A., Naito, Y. & Nishiumi, I. Sexual differences in the diet of king cormorants at Macquarie Island. Polar Biol 16, 75–77 (1996). https://doi.org/10.1007/BF02388738
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DOI: https://doi.org/10.1007/BF02388738