By contrast, snipes have several rest-stop options during their autumn migration to Africa but choose not to take advantage of them.

Also such electromagnetic field changes could be affecting migrating birds and the navigational ability of fish.

Weather can work against them, too, particularly if they migrate too soon in an unseasonably cold year.

The calliope hummingbird weighs only as much as two paper clips, yet it migrates annually between Canada and Mexico.

This old so-called tribal nobility disappeared for the most part during the migrations or soon afterwards.