Main Ref. | Karpouzi, V.S., 2005 |
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Remarks | Found over sea and along shores (Ref. 83946). Colonial breeder on marine islands. Gregarious at sea; sometimes trail ships (Ref. 91362). With one of the largest global populations of >10 million individuals. Found only in the Pacific. Undergoes south to north transequatorial migrations. Huge numbers migrate from the Antipodes to the North Pacific during the northern summer. Long-lived. Half of adults mate with same partner for life, with mean number of partners <2 and 30-40% of mate changes attributed to death of partner. Does not breed in the North Pacific despite multitudes spending austral winter there after their transequatorial migration from breeding areas (Ref. 87784). Breeds only in Australia and Tasmania; spends boreal summer in north Pacific and Bering Sea (Ref. 81748, 87784). In southeast Australia, breeding individuals forage for food for their chicks close to the colony but feed in the rich waters of the Polar Frontal Zone about 1000 km away. Surface foragers and also able to pursue prey underwater by diving (Ref. 87784). Able to plunge deep in water (Ref. 81748). ENSO event of 1997-1998 caused mortality in the thousands linked to starvation caused by movement of warm, nutrient-depleted water (up to 60 m deep) into its area in the Bering Sea and Alaska. Population declines also linked to fishing-net mortality (Ref. 87784). |
Marine - Neritic | Marine - Oceanic | Brackishwater | Freshwater | |
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Marine zones / Brackish and freshwater bodies |
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Substrate | |
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Substrate Ref. | |
Special habitats | |
Special habitats Ref. |
Ref. | Schreiber, E.A. and J. Burger, 2001 |
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Associations | colony-forming/symphorism; |
Associated with | |
Association remarks | Form huge migratory groups (Ref. 87784). Colonial breeder (Ref. 91362). |
Parasitism |
Feeding type | mainly animals (troph. 2.8 and up) |
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Feeding type Ref. | Karpouzi, V.S., 2005 |
Feeding habit | variable |
Feeding habit Ref. | Schreiber, E.A. and J. Burger, 2001 |
Estimation method | original sample | unfished population | Remark | ||
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Troph | s.e. | Troph | s.e. | ||
From diet composition | |||||
From individual food items | 4.07 | 0.64 | Trophic level estimated from a number of food items using a randomized resampling routine. | ||
Ref. |