"Flight Paths" | Reviewed by William Winkler

For many the sight of the first daffodils poking through the cold soil is the earliest sign of spring. For others, it’s the sight of new foliage on the trees. But for avid birders (never “birdwatchers,” please!) it’s the arrival of birds such as orioles, tanagers, and active little warblers, that have migrated from their winter habitats far to the south.

Nature writer and birder Rebecca Heisman has worked as the director of communications for the American Ornithological Society. In her years, in that position, she grew to know many of the society’s leading bird researchers. She was fascinated by the methods employed by these scientists to study the phenomenon of bird migration. The result is her recent book, “Flight Paths."

The earliest efforts to track the movement of migratory birds involved capturing and banding individuals, then relying on the goodness of those who found them later to report the location of their find. The introduction of mist nets to capture birds for banding advanced the process to the point that a year-round program in southwestern Pennsylvania has banded over 700,000 birds since its inception in 1961.

The usefulness of banding is limited by the difficulty in retrieving data from and about individual birds. The growth of electronic miniaturization technology had advanced far enough into the early 1980s that 1.4 ounce tracking devices could be attached to large seafaring birds, enabling them to be tracked by global positioning satellites. And the development of ever smaller devices allowed ever smaller birds to be tracked.

Detailing migration has not been limited to physical observation of bird paths. The recognition that individual geographic regions have unique patterns of hydrogen isotopes in their flora allow researchers to analyze feathers from migratory birds to learn where they have been feeding while on their breeding grounds.

The nearly universal availability of the internet led the Cornell Laboratory of Ornithology to introduce eBird, an online database to which anyone can contribute, in 2002. The observations of citizen-scientists worldwide have advanced new understanding of bird migration patterns, as well as documenting the decrease in the populations of individual species as a result of climate change and habitat loss.

Although dealing with technological advances, Heismann keeps her narrative lively and readable, sprinkling information about some of the more interesting scientists involved in this research. Those who take their birding seriously will find her book a useful addition to their ornithological library.

Buy the Book.