Long-Distance Tweets  The tiny songbird, Northern Wheatear, has
the stamina to make one of the farthest recorded
migrations—scaled for body size—of any bird, as much as 9,000
miles in each direction between the North American Arctic and
Africa.  A Northern wheatear (Oenanthe oenanthe) male  Heiko
Schmaljohann  The northern wheatear, Oenanthe oenanthe, weighing
in at an ounce or less, was known to have one of the largest
breeding ranges for a songbird—stretching from eastern Canada
across Greenland and Eurasia to Alaska— but up to now,
researchers had been unable to establish where the birds that
summered in Canada and Alaska spent the winter.  Equipping
forty-six birds with super-lightweight sensors called
geolocators, which recorded light intensity during the time of
deployment, a team including Franz Bairlein and Heiko
Schmaljohann of the Institute of Avian Research in
Wilhelmshaven, Germany, followed two wheatear populations as
they left from Alaska and the eastern Canadian Arctic. Based on
times of sunset