Peter Doherty, a Nobel Prize-winning immunologist and author of Their Fate Is Our Fate: How Birds Foretell Threats to Our Health and Our World, also recognizes the value of birds as representatives of the wider natural world. Rather than as ambassadors, though, Doherty views birds as prophets of a sort, as “sentinels, sampling the health of the air, seas, forests and grasslands that we share with them.” He presents tales of complicated, messy interactions between birds and humans, often culled from his experience in the world of medicine but also detailing some of the oft-overlooked ways in which subtle human actions can greatly impact birds. To be reminded of this dynamic, Doherty suggests, is to take responsibility for the health of birds, humans and the Earth.
Of primary relevance for Doherty (as for most birders) is that birds are accessible. As the human footprint grows, more terrestrial animals—from bison to lions to kangaroos—are restricted to parks and reserves, as far from human contact as we can get them. Other creatures, like rats and insects, live among us, but they’re too small (and unpleasant, frankly) to earn a widespread following. Birds are it. They live close to us, but travel far and wide. In the sense that humans and birds are both warmblooded vertebrates, we share a physiology, which can be useful because birds can give us clues as to how humans might be affected by outside phenomena.
Doherty thinks we’d be smart to pay attention. He starts with stories from the medical world, illustrating the surprisingly numerous examples of diseases transferred between humans and birds. Naturally, it’s the diseases that birds can transfer to humans that get most of the press. Bird flu (H1N1 and H5N1), West Nile virus, and another disease called psittacosis, or “parrot disease,” which killed at least 33 people between 1929 and 1930, are explained from their feathered origins to their human outbreaks. Lesser known are the plagues humans have wrought upon birds. I hadn’t heard the story of a tick-borne disease brought by sheep-herding monks to Scotland in the 1600s that decimated wild grouse populations, or of the human introduction of malaria and avipox to Hawaii, which have contributed the extinction of about half of the 140 bird species endemic to the islands.
Birds can teach us about more than just communicable diseases, of course. They can teach us about the health of the planet. Take the saga of a shorebird called the red knot, which Doherty uses to illustrate the fragility of natural systems. Over just a few years, a small uptick in the mid-Atlantic catch of horseshoe crabs led to an unfathomable 70 percent decline in the worldwide population of red knots, which depend on horseshoe crab eggs during a crucial time in the birds’ migration. The impacts from climate change and human expansion are becoming easier to see, Doherty explains, thanks to valuable data gathered by birders acting as citizen scientists through Audubon’s Christmas Bird Count and the eBird programs.
Many of us, even birders, can trick ourselves into thinking that there are neat divisions between the natural and the human worlds. Americans have pioneered the idea of the national park—and thank goodness for it—but those parks lead many to think that what exists or occurs outside park borders doesn’t count. The birds in Doherty’s book serve as a valuable reminder that the natural world doesn’t exist in isolation. Wings permit birds to be the last wild intrusions on our lives, their stubborn physiology forcing us to remember that we’re connected to a much larger world. It’s an uninvited reminder but a valuable one, and it’s brought to us by—and I really can’t believe I’m saying this—the magic of flight.
Their Fate Is Our Fate: How Birds Foretell Threats to Our Health and Our World by Peter Doherty. The Experiment.