1 Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, Cornell University, Ithaca, NY, USA. Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA. sat235@cornell.edu.
2 Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, Cornell University, Ithaca, NY, USA. Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.