A World on the Wing

Scott Weidensaul / W. W. Norton / 416 pages

In rich detail, A World on the Wing: The Global Odyssey of Migratory Birds unveils the captivating world of migratory birds, the threats they face, and the scientists and conservationists who strive to protect them. From beginning to end, author Scott Weidensaul induces a sense of awe. Just a few of the tantalizing facts he shares: The annual, pole-to-pole (and back again) journey of some Arctic terns has been tallied at 57,000 miles. Certain songbirds fly up to a week without stopping, fueled by short naps in the air. Some daredevil migratory species fly directly into hurricanes—using the wind to propel them to their destination.

Advances in radio telemetry and radar systems, as well as the ability to leverage big data, have produced a technological revolution so central to modern migratory studies that it nearly becomes a main character in the book. Knowledge gleaned about where birds go, how they use habitat, and how they are affected by habitat quality has revealed the sheer magnitude and complexity of the many threats that migratory species face. It has allowed us to better understand why so many populations are in steep decline but also—as Weidensaul makes clear—to tailor cross-continent conservation efforts to address threats species face at different stages of their lifecycles. 

As with much research aimed at understanding wildlife, the study of migratory birds raises ethical considerations. Some of these are briefly touched upon in the book, mostly in the form of the author’s attempt to assuage readers’ concerns. But lingering questions remain about how researchers came to know certain things, like the fact that many internal organs shrink dramatically while birds are in flight. Certain studies highlight humanity’s compulsion merely to know. In such cases, individuals may be harmed to learn about a species without regard, seemingly, for whether the acquired information might help save the species.

Yet on the whole, the information presented in this book, and the research being conducted, is opening vitally important windows into the world of migratory birds and providing insights essential to ensuring that these winged marvels thrive long into the future.