Reconstructing palaeoflyways of the late Pleistocene and early Holocene Red Knot Calidris canutus.

Bird migration systems must have changed dramatically during the glacial-interglacial cycles of the Pleistocene and as novel habitats became available since the last glacial maximum. This study combines molecular dating of population divergence times with a review of polar-centred palaeovegetation and intertidal habitats world-wide to present a hypothesis for the evolution of Red Knot Calidris canutus flyways. Divergence dates from coalescent analysis of mitochondrial control region sequences indicate that C. c. canutus diverged from the most recent common ancestor (MRCA) of Red Knots about 20 000 (95% CI 60 000-4000) years ago. About 12 000 (95% CI 45 000-3500) years ago this MRCA diverged into two lineages, now represented by the North American breeding C. c. roselaari, C. c. rufa and C. c. islandica and the Siberian breeding C. c. piersmai and C. c. rogersi, respectively. Divergence times of these two Siberian breeding subspecies are about 6500 (95% CI 25 000-1000) years ago, and populations of the North American breeding subspecies are estimated to have diverged within about the last 1000 years.

Buehler D.M., Baker A.J. & Piersma T., ARDEA 94 (3): 485-498