Rapid increase of the grey seal (Halichoerus grypus) breeding stock at Helgoland
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چکیده
منابع مشابه
Decreasing ice coverage will reduce the breeding success of Baltic grey seal (Halichoerus grypus) females.
Baltic grey seals (Halichoerus grypus) alternate between land and ice breeding, depending on ice conditions. We show that the fitness of grey seal females in terms of pup mortality and quality is reduced when breeding on land as compared with ice. The mean preweaning mortality rate on land was 21.1% (range 0% to 31.6%), and correlated with birth density (range 0.5-5.2 pups 100 m(-2)). The mean ...
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STOCK DEFINITION AND GEOGRAPHIC RANGE The gray seal is found on both sides of the North Atlantic, with three major populations: eastern Canada, northwestern Europe and the Baltic Sea (Katona et al. 1993). The western North Atlantic population occurs from New England to Labrador and is centered in the Sable Island region of Nova Scotia (Mansfield 1966; Katona et al. 1993; Davies 1957; Lesage and...
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Consistent individual differences (CIDs) in behaviour, indicative of behavioural types or personalities, have been shown in taxa ranging from Cnidaria to Mammalia. However, despite numerous theoretical explanations there remains limited empirical evidence for selective mechanisms that maintain such variation within natural populations. We examined behavioural types and fitness proxies in wild f...
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A retrospective survey was performed on the presenting conditions of 205 live grey seal pups (Halichoerus grypus) admitted to the Cornish Seal Sanctuary in Gweek, United Kingdom between May 2005 and March 2011. The purpose of the survey was to examine the prevalence of various presenting signs at the sanctuary. The presenting signs were classified into nine non-mutually exclusive categories: oc...
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ژورنال
عنوان ژورنال: Helgoland Marine Research
سال: 2008
ISSN: 1438-387X,1438-3888
DOI: 10.1007/s10152-008-0143-6