Ecological conditions in breeding and non-breeding areas of migrant birds have been linked to their annual survival and production of young, but the role of stopover sites is under-appreciated. Through banding studies and censuses along the flyway from Tierra del Fuego to the Canadian Arctic, the drastic decline in 2000-2001 of Red Knots (Calidris canutus rufa) population summering in southern South America in the northern winter was shown to be related to the overharvesting of horseshoe crabs (Limulus polyphemus) in Delaware Bay, USA, their last stopover site before reaching their breeding grounds, and to the late arrival of the birds at this site. In San Antonio Oeste, Argentina, where 25-50% of the Tierra del Fuego Red Knots population congregates every... |