August 29, 2010 - Night Flight
Welcome to the Nature Notebook.

Late summer nights bring clear skies and cool temperatures. They are great times to sit out and enjoy the stars. It is also a time when songbirds are beginning to migrate. You might hear their calls as they attempt to stay in touch with one another. Why do these day-active birds migrate at night? Warm days produce turbulence in the air making for a bumpy ride. Cooler nights bring more stable air making it easier to fly without being bounced around. Lower temperatures also keep traveling birds cooler as they pump their small wings to cover the miles. Flying in cooler more humid night air also reduces the amount of water birds lose preventing dehydration. Finally, the dark of night hides songbirds from the sharp eyes of daytime predators when traveling long distances in the open.

This is PPL's naturalist, Jon Beam, with the Nature Notebook for WVIA.