Around the world, no matter where we are, we can usually expect the weather to change from one season to the next. In North America, the warm days of summer eventually turn into the cooler days of autumn, and these changes are vital to a lot of the animals that inhabit the region as they trigger the urge of animals to prepare for winter. Migratory animals, like songbirds, use these predictable weather changes as environmental cues to tell them when it’s time to migrate south. But with the earth now getting hotter and hotter each year, birds can no longer rely on the once predictable climate. As autumns are becoming milder, ornithologists keep pondering on how it could be affecting birds’ migratory decisions. Now, a new paper published this week in an online journal Animal Migration, has experimentally investigated how birds use temperature as a signal to migrate.