Climate Central: The American Redstart has an enviable calendar. The tiny songbird spends its winters in Central and South America, then beats the sweltering heat of tropical summers by flying north to breed.
For scientists, the globe-trotting habits of migratory species like the Redstart pose an immense challenge: As the climate warms, how do you protect a species with no fixed address?
"The difficulty with migrating species is that instead of having to worry about one piece of habitat, you typically have...