Brave New Wildlife Biology: The Anti-Audubon
Editor's Note: This is the third part of a four-part story on how new technologies—gene sequencing, GPS tracking, remote monitoring and the like—are revolutionizing wildlife biology for better and, in some ways, for worse. Click here for Part 1, here for Part 2 and here for Part 4.
In a visit to the Cornell Lab of Ornithology in upstate New York—the premier institution for the study of birds, with a staff of 50 scientists and educators—I was amazed by the range of new approaches there, especially the use of sound. The lab has developed software that identifies the noises many kinds of animals make, and offers that software to researchers around the world. The lab also has built a vast audio library, and anyone with Internet access can hear thousands of distinctive birdsongs and the various calls of mammals, amphibians, reptiles, fish and even arthropods. The study of birds began long before binoculars were available; pioneering ornithologist John James Audubon, in the early 19th century, had to shoot birds to study them up close. Today's technologies include arrays of microphones and radar installations to gather data as flocks of snow geese and migrating hummingbirds pass overhead.
At the University of Montana Flight Research Lab, I've watched researchers like Bret Tobalske use lasers and other tools to discover exactly how birds fly, and even to explore how their habitat shapes their physiology. In one experiment in the warehouse-like flight lab, while a Rolling Stones recording rocked out in the background, Tobalske placed a small hummingbird he had captured in his yard into a plexiglass cube. As the tiny bird hovered and drank from a feeding tube, an emerald green laser beam illuminated a fine cloud of olive oil hanging in the air. A camera recorded the movement of the swirling mist, detailing how lift, drag and other forces work on the bird as it flies. By understanding a bird's flying strategies, scientists can learn more about its ecology. The hairy woodpecker, for instance, has evolved a technique to get from one bug-infested tree to another as fast as possible using a minimal amount of energy, with a distinctive combination of flapping and gliding flight. "Flight is extraordinarily expensive per second (when it comes to energy use) and birds have evolved ways to sidestep some of those costs," Tobalske said. "It tells us something about (how they deal with) predator risks and why they feed where they do."
Meanwhile, isotopes—stable compounds created primarily by the planet's geologic processes and then naturally dissolved in water—are being interpreted in new ways to monitor wildlife. When clouds move across the landscape and drop rain, they leave hydrogen, carbon and deuterium and other isotopes in soil and vegetation in unique and varied ratios. So the isotopic fingerprint of, say, the Lamar Valley in Yellowstone National Park is different than that of the Pelican Valley, which is also in the park. When a bear or mountain lion drinks water from different sources, a record of those isotopes is formed in its hair or claws, and biologists can later analyze it to determine where the animal has been drinking. Researchers analyzing isotopes can also identify what portion of a bear's diet is meat, vegetation or fish. The technique does not require trapping the animal, but it does require gathering isotopic ratios across vast areas—known as "isoscapes"—to accurately compare an animal's tissue with the places on the landscape it has visited.
That technology has other uses: After a camper was attacked and killed by a grizzly near Yellowstone in 2010, for instance, biologists killed the bear and tested a snip of its hair for a corn isotope. Since almost every processed food contains corn syrup, they could discover if the bear in question had been corrupted by human garbage. In this case, it hadn't.
Fishery biologists in Yellowstone remove the calcium carbonate otolith, or "ear-stone," from dead fish to discover where the fish swam when they were alive. Tom McMahon, a professor of fishery biology at Montana State University, explained that technique: The otolith forms as a fish grows, and incorporates distinctive isotopes from each tributary it visits, so by analyzing it, "You can backtrack on (the fish's) movements through its entire life."
This story first appeared in High Country News.