A polar system of intercontinental bird migration by Prof Thomas Alerstam et al.
Cross-hemisphere migration of a 25 g songbird by Franz Bairlein et al.
One of our heroes Prof Tomas Alerstam has directed us to this fascinating paper by Heiko Schmaljohann et al from 2012. It relates to northern Wheatear, (Oenanthe oenanthe), a small long-distance migratory songbird, migrating exclusively by itself at night going from Alaska, its breeding ground, to East Africa for the winter. It covers all the issues that a migratory bird faces and is very strong on the energy needed to carry out these migrations. Just like other migratory birds the journey south to their wintering grounds from their arctic breeding grounds is more leisurely and slow than the impulsion to get back to their breeding grounds to make the most of the short Arctic summer. It is important to note that Fledglings that have never made the journey before have no problem doing it.
The other papers are equally interesting covering the Wheatear which go across the Atlantic to get to Western Africa to winter and also The original paper by Prof Alerstam where he used an ice breaker to track the migratory birds in the Arctic.
As Prof Alerstam so kindly put it:
“I am sorry to say that new studies of the Wheatear migration by Bairlein and Schmaljohann clearly indicate that the birds do not follow great circle routes. Still the great circle hypothesis could still apply to the arctic shorebirds (including the phalaropes).
I enclose some papers in PDF-files to show the new results for wheatears and the available data for the shorebirds.
With all best wishes!