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The outer Bay of Fundy, eastern Canada, is an important feeding area for migrant Grey and Red-necked Phalaropes Phalaropus fulicarius and P. lobatus in late summer. The birds feed on copepod-sized zooplankton, brought to the surface by the passage of strong tidal streams over shallow, rocky ‘ledges’, and concentrated there in upwelling and convergence ‘streaks’. Feeding phalaropes are significantly more abundant in the ‘streaks‘ than in adjacent ‘contro’ areas. Red-necked Phalaropes are the more common species; they prefer the New Brunswick shore, where copepod biomass is high and the species-community is dominated by large, Stage VI-V Calanus finmarchicus. Grey Phalaropes occur mainly on the Nova Scotian side of Fundy, where the copepod biomass, and the dominant species, are smaller. The feeding habits of both species, and their non-breeding distributions, are reviewed. It is concluded that upwellings, convergences, and other oceanographic phenomena that concentrate zooplankton at the surface are the principal factors influencing the pelagic ecology of phalaropes. |
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