Influence of sea surface winds on shearwater migration detours

Migration is a major activity in the life of many seabird species. Twice a year millions of shearwaters travel 10s of 1000s of kilometres across the equator to move between wintering and breeding areas. Ringing programmes, land-based observers and observations at sea have provided some information on broad-scale migration corridors (Serventy 1953, Alerstam 1990, Brooke 1990 These studies have suggested a figure-eight pattern, clockwise in the northern and counter-clockwise in the southern hemisphere, but detailed migration pathways remain largely unknown. Currently, tracking devices provide invaluable information on spatial and temporal aspects of the migration at an individual level (Shaffer et al. 2006, Gonzlez-Sols et al. 2007). These studies have confirmed that shearwaters often do not travel the shortest distance between breeding and wintering areas, but may take longer pathways than expected. Furthermore, the figure-eight pattern of annual movements