What scientists learn from footsteps of ants and elephants
NONFICTION
We’ve come a long way from the days when Aristotle believed that storks winter on the moon. Now GPS tags, DNA sequencing, satellites and cellphone networks allow scientists to track animals across vast stretches of land and through sky and sea.
In “Where the Animals Go,” geographer James Cheshire and Oliver Uberti, a former design editor for National Geographic, showcase some of the latest information on animal movement gleaned from these new technologies. Through colorful maps, detailed graphics and explanatory essays, the book presents in intimate detail the comings and goings of species across the animal kingdom, from ants and bees to jaguars, baboons, vultures and, yes, storks.
“Where the Animals Go” is full of unexpected information: When geese fly over the Himalayas, for example, their hearts beat up to 500 times per minute. “Some geese crossed the Tibetan Plateau in less than a day at record-breaking climb rates of 2.2 kilometers per hour,” Cheshire writes. “That’s like ascending from sea level to the summit of Mount Everest in four hours. What’s more, they do so without acclimatization, rest, or help from the wind.”
Other chapters demonstrate the risks animals face as they try to make their way to food and water and to mate. By monitoring the speed and direction of elephants, for example, researchers can determine whether they have been harassed by armed herders. In a fascinating essay, “The Elephant Who Texted for Help,” Uberti describes how the GPS collar of a Kenyan elephant alerted researchers that the animal had been shot; watching from a researcher’s living room, scientists followed its tracks on screen, all the way until the moment it sadly succumbed to its wounds.
This and other chapters demonstrate how human intrusion has disrupted animals’ movement and in some cases put their very existence in peril. Tracking devices and genetic analysis have shown, for example, that mountain lions in the Santa Ana Mountains near Los Angeles have become “effectively marooned on an island, surrounded by freeways and ever-encroaching human development.” Since 2001, the authors report, “only one tagged lion … has managed to cross Interstate 15 in either direction, but he was killed 25 days later for preying on a rancher’s sheep.” The long-term effect is stark: “Without the ability to breed with other gene pools, the Santa Ana population is in jeopardy.”
GPS and other technology make such discoveries possible, but tagging animals is itself risky. The simple act of “catching an animal is about the most horrible thing that can occur to it,” says biologging pioneer Rory Wilson. Even if you “catch it and let it go, it’ll have the heebie-jeebies for weeks.” A GPS collar can compromise the “100% intact fur barrier” otters need to protect them from cold. Because a puncture in their fur could mean death, scientists use internal tags on otters instead. With such precautions, says Iain Douglas-hamilton, the founder of Save the Elephants, “stress can be minimized” so that the “risk is outweighed by the enhancement of the survival chances that comes from what we learn through the tracking.”
Cheshire and Uberti write about billions of data points being collected — some by citizen scientists — and their ravishing maps put this information to good use, but what’s missing here is a deeper discussion of habitat loss, which is already changing the ways animals move. Storks, as Cheshire and Uberti point out, don’t always migrate now; it’s easier to feed on garbage dumps. The habitat conversation we need to have now is about how urban environments are an underutilized resource and rewilding our backyards can offer sorely needed rest stops for small migrating birds.
Mapping animal migrations can help government officials to draw park boundaries more strategically to protect animals such as oilbirds, who have a wider range than was previously understood. Cheshire writes, “In order to fully understand why something happens we often need to know where it happens.” Cheshire and Uberti, and the scientists whose work they have interpreted, show us with precision and clarity where the animals go. Whether we will give, say, mountain lions the corridors they need to cross our freeways without getting hit is another matter.
Priyanka Kumar is the author of the novel “Take Wing and Fly Here” and the writer/director of the documentary “The Song of the Little Road.”