Red Knot (Calidris canutus) Science Article 2 abstract This study examines fuel use and metabolism in a group of long-distance migrating birds, red knots Calidris canutus (Scolopacid ), flying under controlled conditions in a wind tunnel for up to 10 h. Data are compared with values for resting birds fasting for the same time. Plasma […]
Two estimates of the metabolic costs of antibody production in migratoryshorebirds: low costs, internal reallocation, or both?
Red Knot (Calidris canutus) Science Article 5 abstract We measured the costs of mounting a humoral immune response using two novel antigens (tetanus and diphtheria) in two shorebird species (Scolopacid ): Red Knot (Calidris canutus, measured in autumn) and Ruff (Philomachus pugnax, measured in spring). Metabolic rate was measured during the preinjection phase, at the […]
Body transformations, condition, and survival in Red Knots Calidris canutus travelling to breed at Alert, Ellesmere Island, Canada.
Red Knot (Calidris canutus) Science Article 11 abstract This paper reviews the nutrient storage dynamics and body changes of Red Knots Calidris canutus islandica during migration through their final spring stopover area in Iceland and after arrival on the breeding grounds in the northeastern Canadian High Arctic at Alert. In Iceland, Knots not only accumulate […]
Southward migration and fuel deposition of Red Knots Calidris canutus.
Red Knot (Calidris canutus) Science Article 10 abstract We compared the differences between spring and autumn in migration speed, fuelling rates and fuel loads of migrating Red Knots Calidris canutus. As a basis we used ringing data from Ottenby Bird Observatory, southeastern Sweden, collected 1948-2003, with morphometrical data from 1990-2003. Numbers ringed varied between 0 […]
Digestive bottleneck affects foraging decisions in red knots Calidris canutus. I. Prey choice
Red Knot (Calidris canutus) Science Article 14 abstract Rate-maximizing foragers that only divide their time between searching and handling prey should, according to the classical contingency model (CM), only select those prey whose energy content per unit handling time (i.e. profitability) exceeds or equals long-term average energy intake rate. However, if digestively constrained foragers were […]
Modelling phenotypic flexibility: an optimality analysis of gizzard size in Red Knots Calidris canutus
Red Knot (Calidris canutus) Science Article 13 abstract Reversible phenotypic changes, such as those observed in nutritional organs of long-distance migrants, increasingly receive the attention of ornithologists. In this paper we review the cost-benefit studies that have been performed on the flexible gizzard of Red Knots Calidris canutus. By varying the hardness of the diet […]
Reconstructing palaeoflyways of the late Pleistocene and early Holocene Red Knot Calidris canutus.
Red Knot (Calidris canutus) Science Article 12 abstract Bird migration systems must have changed dramatically during the glacial-interglacial cycles of the Pleistocene and as novel habitats became available since the last glacial maximum. This study combines molecular dating of population divergence times with a review of polar-centred palaeovegetation and intertidal habitats world-wide to present a […]
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 […]
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 […]
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, […]