Great Cormorant (Phalacrocorax carbo) Science Article 24 abstract The wintering population of Cormorants Phalacrocorax carbo in France reached 66000 birds in January 1992 against 14 000 in 1983. This increase largely concerned the inland areas (holding 55% of the population instead of 28% in 1983). The most important area is the Loire Valley. Analysis of […]
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Subspecific identity of prehistoric Baltic Cormorants Phalacrocorax carbo.
Great Cormorant (Phalacrocorax carbo) Science Article 30 abstract Cormorants of the subspecies Phalacrocorax carbo sinensis breed in large numbers in the Baltic Sea. They migrate to the Mediterranean region to winter and are then replaced in the Baltic by wintering individuals of the Norwegian population of the nominate subspecies carbo. Cormorants bred in the Baltic […]
The relative importance of physiological and behavioraladaptation in diving endotherms: a case study with great cormorants
Great Cormorant (Phalacrocorax carbo) Science Article 10 abstract Extensive morphological and physiological adjustments are assumed to underpin the adaptations of diving birds tohigh thermoregulatory costs. However, the role of behavioral adaptations has received little consideration. We have assessedthe relative importance of physiological and behavioral adjustments in aquatic endotherms by studying the case of the poorlyinsulated […]
Variation in contaminant content of livers from Cormorants Phalacrocorax carbo sinensis living nearby a polluted sedimentation area in lake Ijsselmeer, The Netherlands.
Great Cormorant (Phalacrocorax carbo) Science Article 13 abstract The livers of 23 Cormorants drowned in fishing gear in the vicinity of the contaminated lake Ketelmeer, part of the lake IJsselmeer area, The Netherlands, were analysed for contents of a series of heavy metals and chlorinated hydrocarbons. Individual differences found were related to age, sex and […]
Mass fishing by Cormorants Phalacrocorax carbo sinensis at lake Ijsselmeer, The Netherlands: A recent and successful adaptation to a turbid environment.
Great Cormorant (Phalacrocorax carbo) Science Article 20 abstract The habit of mass fishing by Cormorants at lake IJsselmeer, The Netherlands, is a recent phenomenon. During the first half of the 1970s the birds changed behaviour probably as a result of the deteriorating under water visibility in the take (3-4 m water depth). The behavioural switch […]
Individual migration strategies in Cormorants Phalacrocorax carbo passing through or wintering in western France.
Great Cormorant (Phalacrocorax carbo) Science Article 16 abstract The attendance of individually recognisable Cormorants has been studied at a roost site in western France together with the overall use of this roost. Only first and second year birds arrived at the roost before mid-October and almost only 1st-year birds did so after February. In the […]
Are Cormorants Phalacrocorax carbo wintering in Switzerland approaching carrying capacity? An analysis of increase patterns and habitat choice.
Great Cormorant (Phalacrocorax carbo) Science Article 17 abstract The increase rate of Cormorant numbers overwintering in Switzerland between 1970 and 1990 was the same as in the strongly growing breeding population. From 1930 to 1970, however, wintering Cormorants increased while the breeding population remained stable. The reasons are believed to be a better food supply […]
Time and energy constraints of fishing behaviour in breeding Cormorants Phalacrocorax carbo sinensis at lake Ijsselmeer, The Netherlands.
Great Cormorant (Phalacrocorax carbo) Science Article 18 abstract Two Cormorant colonies in The Netherlands (Naardermeer and Oostvaardersplassen), exploiting the same water bodies but situated at different distances from them, were compared with respect to daily variations in exact fishing sites and corresponding variations in time budget and fish consumption. Mean flying distances between colony and […]
The telltale heart: A non-invasive method to determine the energy expenditure of incubating Great Cormorants Phalacrocorax carbo carbo.
Great Cormorant (Phalacrocorax carbo) Science Article 31 abstract We studied the energetics of incubating Great Cormorants Phalacrocorax carbo carbo via heart rate and respirometric measurements performed in captive and free-living animals. We applied a modified heart beat frequency (HR) monitor built for use in human athletics as well as respirometry for measurements in four captive-bred […]
Roach rules: Shoaling fish are a constant factor in the diet of Cormorants Phalacrocorax carbox in Switzerland
Great Cormorant (Phalacrocorax carbo) Science Article 29 abstract The spatial and temporal variation in the diet of Cormorants Phalacrocorax carbo visiting Switzerland in the non-breeding season was studied from 1985-1992, by means of regurgitated pellets and stomach contents. The results, combined with the data of most other dietary studies from Switzerland since 1974, rest on […]