1. Department of Ecology and Evolutionary Biology, Princeton University,Princeton, NJ 08544, USA
2. Mammal Lab, New York State Museum, CEC 3140, Albany, NY 12230,USA
3. Department of Mechanical and Aerospace Engineering, Princeton University,Princeton, NJ 08544, USA
4. Copenhagen Bird Ringing Centre, Zoological Museum, University of Copenhagen, DK-2100 Denmark
5. Goddard Space Flight Center, NASA, Greenbelt, MD 20771, USA
6. Department of Electrical and Computer Engineering and Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801,USA