The Red Knot breeding with six subspecies in the high Arctic tundra makes one of the longest migrations of any bird, traveling up to 16,000 km twice a year. The different knot populations are migrating in some of the largest non-stop leaps known from any species along all the main continental coastal flyways to their southern wintering sites. The species is highly dependent on large tidal flat areas with abundant food recourses (mainly small shell fish such as Macoma baltica) as staging areas (“spring boards”) to fill up fat reserves enabling them to make the up to 5000 km long non stop-flights. Calidris c. canutus traveling from South Africa along to the East Atlantic flyway via the Banc d’Arguin/Mauritania and the Wadden Sea to Taimyr / North Siberia undertake the physiologically extreme performance each spring to refuel at least 3 times fat reserves (doubling weight) during 3 weeks fast feeding and fly this fuel off within 2-3 days on their large distant non-stop leaps.
From album: The Red Knot and Long-Distance Migration