Jay Shefsky takes a road trip to see 15,000 Sandhill Cranes in Indiana. Jay and his Field Museum guide, Josh Engel, get a surprise along the way.

Every year at this time, Sandhill Cranes migrate south. But this year, the skies over Chicago seem to be full of them. Field Museum ornithologist Josh Engel explains why.

Brutal winter conditions this year devastated the bird population in the Midwest region. The Field Museum has collected roughly 60 specimens but many more have perished as a result of starvation from limited open water on Lake Michigan. We speak with Field Museum research assistant and ornithologist Josh Engel about the phenomenon. Read an article and view a slideshow.