THE WINTER FEEDING ECOLOGY OF THE REDSHANK TRINGA TOTANUS

摘要: Summary. The aim of the work was to find out how Redshank which over-winter on Ythan estuary, Aberdeenshire, adapt their feeding activities short daylength in winter. To achieve this, behaviour and daily routine winter were compared with those autumn spring. Corophium volutator main prey estuary during day. However, temperature mud greatly affected diet two areas where studied detail. At temperatures above 6°C, most biomass ingested consisted Corophium. one study area winter, Macoma balthica taken more frequently at lower than high temperatures. In other area, Nereis diversicolor low These changes appeared related affecting availability not due birds changing preference The ingestion rate by change first but decreased second. sizes did vary seasonally. Corophium as a result reduction size present substrate. It concluded that there no evidence increasing compensate for daylength. The proportion time spent daylight greater spring. continued water surrounding fields night either or During they obtained less 50% food requirements from daylight, mainly because daylength. Consequently, had collect balance water. Seasonal numbers recorded. After an decrease numbers, could be detected findings are discussed relation possible difficulties collecting impact estuarine is also discussed.