When you think of migrating birds, you may picture something like geese flying overhead in their distinctive V-formation. But what about the many species of birds that migrate at night? For these species, researchers rely on indirect observation methods to study their paths, habits and behaviors.

New Mexico State University Ph.D. candidate Dylan Osterhaus authored a review paper on the field of nocturnal flight call monitoring, outlining everything from advancements in technology and research methods, to future applications and current limitations. Osterhaus’s paper was recently published in the premier academic journal Ornithology. It is the first review of this rapidly expanding research area since 2005.