Tag: Razorbill

Age at First Return and Breeding of Razorbills (Alca torda)on theGannet Islands, Labrador and Machias Seal Island, New Brunswick

Razorbill (Alca torda) Science Article 11 abstract Resightings of Razorbills (Alca torda) banded as chicks on the Gannet Islands, Labrador (N = 1,873resightings of 638 individuals) and Machias Seal Island, New Brunswick JENNIFER L. LAVERS, Waterbirds 31(1): 30-34, 2008 Download article download full text (pdf)

Sexing Razorbills Alca torda breeding at Machias Seal Island, New Brunswick, Canada, using discriminant function analysis.

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 […]

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 […]

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 […]

Effects of island isolation and feral mink removal on bird communities (Alca torda) on small islands in the Baltic Sea

Razorbill (Alca torda) Science Article 7 abstract 1.) Predation has been suggested as a major cause affecting survival, reproductive success and behaviour in vertebrate prey populations. The breeding season is a critical phase because the essential difference between selecting the proper nest site may be a question of breeding success and failure. 2.) Islands may […]

Sexual Size Dimorphism and Assortative Mating in Razorbills (Alca torda)

Razorbill (Alca torda) Science Article 1 abstract My primary aim here is to report the first large data set of live, known-sex Razorbills and to identify the degree of sexual size dimorphism in a number of body measurements. This Study is part of a wider project on mating behavior of Razorbills based on color-banded breeding […]

Wear and loss of rings used on Razorbills Alca torda

Razorbill (Alca torda) Science Article 3 abstract On Grasholmen in the central Baltic Sea, 3,583 Razorbill Alca torda chicks were ringed with triangular Incoloy rings, and about half the birds were subsequently resighted. The resightings were used to calculate rates of turned rings, and 119 retrieved rings were used to calculate rates of wear and […]

Survival and age at first breeding in the Razorbill (Alca torda)

Razorbill (Alca torda) Science Article 2 abstract Observations of banded birds on Skokholm were made during daily visits to the cliffs between mid-March and mid-August (1971-73), and the work was continued by the staff of the Bird Observatory in 1974. In one study colony, The Bluffs, visited daily throughout the season, the birds became tame, […]