Shrinking shorebird pays the bill for rapid Arctic warming while wintering in the tropics

Description

Red knots (Calidris canutus canutus) migrate between their summer breeding grounds in the high Arctic and their wintering grounds in the West African tropics. An international team of scientists discovered that chicks currently born under rapidly warming conditions in the Arctic attain smaller sizes before migration starts because they miss the insect peak. If they make it all to their wintering grounds on the African intertidal flats, they are there faced with a second disadvantage: their shorter bills hamper their ability to reach their favourite shellfish food in the tropics. This results in an evolutionary force towards smaller-sized birds with relatively large bills.