OOSTEN H.H. VAN, VERSLUIJS R, & WIJK R. VAN (2014) Migration routes and wintering areas of two Dutch Northern Wheatears Oenanthe oenanthe in the Sahel. LIMOSA 87 (2): 168-173.

The Dutch population of Northern Wheatear (hereafter wheatear) has declined by 80% since 1980, without reasons being sufficiently known. Stimulated growth of nitrophilic grasses by deposition of atmospheric nitrogen, reinforced by the decline of grazing Rabbits Oryctolagus caniculus, rendered previously short vegetations unsuitable for foraging wheatears and reduced the availability of nest-sites. However, seemingly suitable sites remain or are currently being restored without being graced by breeding wheatears. Additional causes may thus play a role, which partly might act during migration or on the wintering grounds in Africa. To determine where Dutch wheatears winter and how they get there, we deployed light-level geolocators on nine birds, of which four returned and two yielded data. An adult male from the coastal dune region migrated 4600 km to winter in southern Mali, and a young female from an inland heath flew 4200 km to a winter destination 600 km to the northwest in southern Mauritania. Spring migrations were completed faster (219-300 km/d) than autumn migrations (107-127 km/d), when short stopovers were made in Europe and longer ones in southern Iberia or the northern edge of the Sahara desert (Fig. 1, Tab. 1).

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