I took this image last year up in Churchill as these guys were migrating through. There were some pretty steady north winds and the migrants were all stacking up in Churchill. I noticed that these birds were hanging around one particular area quite a bit and upon investigating saw that there had been some grain spilled on the railway tracks that they were all gobbling up. Perfect! I created a little mound of moss...plunked it in the grain pile...got down on my belly and...here you have it
Camera Model: Canon EOS 7D
Shutter speed: 1/500 sec
Aperture: 8
Exposure compensation: +1/3
Flash: On
ISO: 400
Lens: EF500mm f/4L IS USM +1.4x