Planet Earth online has an article on this picked up from a paper in the latest issue of Ibis
The Planet Earth article can be viewed here.
The original Ibis article is free to view for a short period - see here.
British Ornithithologists' Union
www.bou.org.uk | www.ibis.ac.uk
You've linked the wrong Ibis article here!
My apologies, the full paper is at -
A birdwatching guide to Lesvos
Watching British Dragonflies