Dierschke J. & Bairlein F. (2002) Why did granivorous passerines wintering in Wadden Sea salt marshes decline? ARDEA 90 (3): 471-477

A strong decline of Shorelarks Eremophila alpestris, Twite Carduelis flavirostris and Snow Buntings Plectrophenax nivalis has been noted in the breeding and wintering areas. In the wintering areas in the German Wadden these species roost mainly in low salt marshes and tidelines and feed mainly on seeds of low salt marsh plants. Shorelarks showed considerable site fidelity between winters and small home range, whereas Snow Buntings were much less site faithful and occupied large home ranges. Twite differed between individuals in the size of their home range and site fidelity. The results suggest that the decline of these species may have been caused by habitat destruction by huge embankment projects in the Wadden Sea from the 1960s onwards. Since the late 1980s, the better protection of the Wadden Sea led to a stop of embankments and salt marsh areas have increased in size since, followed by an increase in wintering numbers of Shorelarks, Twite and Snow Buntings. The availability of halophyte seeds is suspected to limit the population size of wintering granivorous passerines in the Wadden Sea