Razorbill (Alca torda) Science Article 5 abstract In 2000 and 2001, we determined the sex of 80 adult Razorbills Alca torda caught on Machias Seal Island, New Brunswick, Canada, 71 birds in 2000 and 9 in 2001. Sex was determined for the 2000 birds using DNA from feathers, and for the 2001 captures using behavioural […]
Category: Charadriiformes
Distribution, migrations and biometrics of Knots Calidris canutus canutus on Taimyr, Siberia
Red Knot (Calidris canutus) Science Article 7 abstract Studies carried out in northern Taimyr in 1982-84 and 1990-92 were combined with data from other sources to describe the breeding distribution and densities and the migration of Knots at Taimyr Peninsula, north-central Siberia. Morphometrics, recent ring recoveries, dates and directions of migration all support the idea […]
Cost-benefit analysis of mollusc eating in a shorebird I. Foraging and processing costs estimated by the doubly labelled water method
Red Knot (Calidris canutus) Science Article 4 abstract Although the energy costs of foraging and food processing in vertebrates may be considerable, they have rarely been quantified separately. Here we present estimates for both cost factors based on a series of trials with a shorebird, the red knot Calidris canutus, fed natural and artificial prey […]
Endogenous circannual rhythmicity in a non-passerine migrant, the Knot Calidris canutus.
Red Knot (Calidris canutus) Science Article 8 abstract We present experimental evidence for endogenous control of circannual rhythms in a long-distance migratory wader, the Knot Calidris canutus. Six individuals of the subspecies canutus were caught during northward migration whilst staging in France, and were held together under constant temperature and photoperiodic conditions (15 degree C, […]
Where waders may parallel penguins: Spontaneous increase in locomotor activity triggered by fat depletion in a voluntarily fasting Knot.
Red Knot (Calidris canutus) Science Article 6 abstract A Knot Calidris canutus, kept with four conspecifics on an enclosed artificial outdoor tidal flat in The Netherlands, refused to feed on the available bivalve prey for a period of 18 days and thereby decreased in mass from 209 g to 107 g, at which point the […]
Length of stopover, fuel storage and a sex-bias in the occurrence of two subspecies of Red Knots Calidris c. canutus an d C.c. islandica in the Dutch Wadden Sea during southward migration.
Red Knot (Calidris canutus) Science Article 1 abstract During southward migration the Wadden Sea is the meeting place of Red Knots Calidris canutus of two subspecies that breed in either western Siberia (C. c. canutus) or north Greenland and north-east Can ada (C. c . islandica), but the details of their co-occurrence have not been […]
Can Norwegian and Russian Razorbills Alca torda be identified by their measurements
Razorbill (Alca torda) Science Article 4 abstract Razorbills Alca torda were measured in one Russian and five Norwegian colonies. A comparison with measurements from colonies in Britain, Ireland, Iceland and the Baltic Sea shows a clear correlation with the geographical position of each colony and a clinal increase in size from the south-west to north-east. […]
Diet of Razorbill Alca torda chicks on Gr sholmen, central Baltic Sea
Razorbill (Alca torda) Science Article 6 abstract This paper describes the food of Razorbill Alca torda chicks on Gr sholmen in the central Baltic Sea and concludes that sprats Sprattus sprattus form the main diet, although sandeels Ammodytes sp. in some years constitute up to 22% by number. Clupeids, mainly sprats, are the most important […]
Winter distribution, ecology and movements of Razorbills Alca torda and other auks in the outer Bay of Fundy, Eastern Canada.
Razorbill (Alca torda) Science Article 8 abstract Casual observations between 1992 and 1997 indicated that up to 25,000 Razorbills may occur around Grand Manan Island, Bay of Fundy, from December to February
IMPACTS OF INTRASPECIFIC KLEPTOPARASITISM ANDDIET SHIFTS ON RAZORBILL ALCA TORDA PRODUCTIVITYAT THE GANNET ISLANDS, LABRADOR
Razorbill (Alca torda) Science Article 10 abstract Intraspecific kleptoparasitism, the stealing of food from members of the same species, has received widespread but mostly superficial attention in the scientific literature. However, the effects of such behavior can be significant. Here we report on high rates of intraspecific kleptoparasitism in the Razorbill Alca torda at the […]