We are used to seeing Red Knots in huge numbers, often as part of an inspiration of waders swirling over an estuary. But are these experiences on the way out.
In Delaware Bay each year the Red Knots Calidris canutus rufa are monitored and counted as well as other waders/shorebirds that pass through on their way to the Arctic to breed. This year and astonishingly low number of Red Knots were recorded. Only 6,800 were found in an aerial survey. In 1983 there had been 95,000 and as recently as 2020 there were still 20,000. This decline also shows in Semipalmated Sandpipers where a 70% reduction has been noted and also in Ruddy Turnstones.
What has caused this? It is unclear what has precipitated such a collapse, but last year’s disastrous lack of Horseshoe Crabs must have left a large proportion of the population unable to reach their breeding grounds due to starvation. Storms and other factors may also have taken their toll.
Similarly in the East Asian Australasian Flyway the numbers are down, In Bohai Bay the Global Flyway Network annual count of Red Knot C. c. rogersi & piersmai produced fewer than 10,000 birds, down from an already low figure of 20,000 in 2020.
These findings are alarming and sad. Are we actually witnessing the demise of wader populations worldwide, especially those involving long distance migrations?