Large-Scale Monitoring of Waders on Their Boreal and Arctic Breeding Grounds in Northern Europe

Abstract

Large-scale and population-wide monitoring of waders on their boreal and arctic breeding grounds has hitherto been lacking, mainly because logistics are truly challenging in regions with few ornithologists, vast areas and few roads. In Norway, Sweden and Finland (here ‘Fennoscandia’) there are now national monitoring schemes in place, aimed at tracking all bird species, which allows trends to be estimated for northern wader populations. We present joint Fennoscandian population trends for 24 wader species, covering the period 2002–2013 (in some cases somewhat shorter time periods). The data stem from 1263 routes in Norway, Finland, and the northern two thirds of Sweden, all situated north of 58°N. This area of one million km2 largely coincides with the boreal and arctic parts of Fennoscandia. The trends found are rather evenly distributed between strong increases and strong declines. Trends do not differ between short- and long-distance migrants, nor do they vary in relation to breeding latitude. Ringed Plover Charadrius hiaticula, Wood Sandpiper Tringa glareola, Green Sandpiper T. ochropus and Common Redshank T. totanus had significant positive trends, whereas Common Snipe Gallinago gallinago, Ruff Philomachus pugnax and Spotted Redshank Tringa erythropus were declining significantly in numbers. Trends could be calculated even for relatively uncommon breeding birds such as Temminck's Stint Calidris temminckii, Eurasian Dotterel Charadrius morinellus, Broad-billed Sandpiper Limicola falcinellus, Jack Snipe Lymnocryptes minimus and Red-necked Phalarope Phalaropus lobatus, although these trends build on few routes and individuals, and thus have low precision. The monitoring schemes in Norway and Finland are expected to increase in coverage in the coming years, with up to a total of 1555 northern routes being tracked when the schemes are fully developed. This should enable still more robust trend estimates for northern waders on their Fennoscandian breeding grounds to be calculated in the future.