Changes in numbers and distribution of wintering waterbirds at the south coast of Scania, Sweden, during 55 winters, 1964–2018

Leif Nilsson

doi:10.34080/os.v30.19987

Abstract

The south coast of Scania, southernmost Sweden, has long been an important wintering and staging area for waterbirds. A large part of the coast was surveyed annually as a part of the international midwinter counts for 55 years (1964–2018). The total number of wintering waterbirds showed an increasing trend but there was much variation between years. Common Goldeneye Bucephala clangula, followed by Mallard Anas platyrhynchos, Tufted Duck Aythya fuligula and—during the early years—Long-tailed Duck Clangula hyemalis, dominated the community. Great Cormorant Phalacrocorax carbo, Mallard, Common Goldeneye and Eurasian Coot Fulica atra increased in numbers, reflecting the national and international trends related to milder winters and a northward shift of the winter distribution. Eurasian Wigeon Mareca penelope and Great Crested Grebe Podiceps cristatus established wintering traditions in the area during the study period. Tufted Duck and Common Merganser Mergus merganser decreased locally due to a northward shift of the wintering distribution northwards within the country. The Long-tailed Duck was an important winter guest in the first years but was only seen in very small numbers in later years, reflecting the general and large-scale decrease of the Baltic wintering population.

Highlights

The south coast of Scania, the southernmost province of Sweden, has since long been known as an important wintering area for a number of waterbird species, being an area offering at least some open water even during the coldest winters.During the years 1964–1969, intensive studies of the non-breeding ecology of diving ducks was undertaken in SW Scania with the main part of the south coast of the province and areas in the Öresund as main study areas
The studies included local distribution and habitat selection, seasonal appearance, feeding ecology, and the exploitation of feeding areas. After this period of intensive work, the wintering waterbirds in the old study area were surveyed in midwinter each year as part of the international midwinter counts organized by Wetlands International (Nilsson 2008, Nilsson & Haas 2016)
The most common species over the years was the Common Goldeneye Bucephala clangula with 35 % of the total number of individuals observed over the 55 years of midwinter counts in the area

Summary

Introduction

The south coast of Scania, the southernmost province of Sweden, has since long been known as an important wintering area for a number of waterbird species, being an area offering at least some open water even during the coldest winters (cf. e.g. Nilsson 1972, Nilsson 2008, Nilsson & Haas 2016).During the years 1964–1969, intensive studies of the non-breeding ecology of diving ducks was undertaken in SW Scania with the main part of the south coast of the province and areas in the Öresund as main study areas (cf. Nilsson 1970a, 1970b, 1970c, 1972, 1975). During the years 1964–1969, intensive studies of the non-breeding ecology of diving ducks was undertaken in SW Scania with the main part of the south coast of the province and areas in the Öresund as main study areas (cf Nilsson 1970a, 1970b, 1970c, 1972, 1975). The studies included local distribution and habitat selection, seasonal appearance, feeding ecology, and the exploitation of feeding areas. After this period of intensive work, the wintering waterbirds in the old study area were surveyed in midwinter each year as part of the international midwinter counts organized by Wetlands International (Nilsson 2008, Nilsson & Haas 2016). I will establish, for the different species, whether there have been any changes in numbers and local distribution over the years

Methods

Results

Conclusion