If birds left tracks in the sky, what would they look like ... so must a pattern form in the wake of a flying bird. But of course birds in flight leave no trace—at least none visible to the ...

The massive annual spring migration of America's birds – millions of them – is underway. Here's how to follow along at home.

Many of the birds that fell dead from the sky were discovered with a mysterious blue stain in their beaks. In the past week, similar incidents of mass animal deaths have been reported across the world ...