My favorite epoch in Earth history is the Ice Age, the time in which saber tooth tigers and giant mastodons roamed the world. The Ice Age ended 10,000 years ago when – quite abruptly – the bitter temperatures of the time gave way to our present, balmy epoch.
Natural history museums often have the skeletal remains of Ice Age mammals. They are enough to inspire awe in part because many of the species alive during that time were much bigger than modern animals. The Ice Age was a time of giant deer and moose, with a species of beaver as large as a modern black bear.
In short, it was a time not long ago with a climate and ecology so different it intrigues both geologists and school children.
Imagine my pleasure, then, when I recently got to hold a sample of 16,000-year-old woolly mammoth poop from the Ice Age. Talk about an intimate connection with the past!
Ancient poop is known to geologists as coprolite material. It can be truly fossilized as solid rock, or just preserved in glacial ice, permafrost or dry caves. One geology department softball team I knew proudly named itself the “Coprolites.” Such is geologic humor.
Ancient mammoths and other prehistoric animals were well defined by the phrase, “you are what you eat.” And by studying what ancient animals ate — through their intestinal remains or their poop — we can learn about their diets and nutrition.
Bruce Davitt of the Department of Natural Resource Sciences at Washington State University has the habit of studying ancient and modern poop — and deducing from it important clues to animal habits and environments. In one case he looked at caribou dung found in a permanent snow patch in southern Yukon, outside of Whitehorse. Caribou haven’t been present in the area since the 1800s, so obviously the dung was at least that old. But using radioactive-dating techniques, researchers found the dung was about 2,400 years old.
Enter Davitt and his special talents at examining poop.
“We looked at the material under the microscope and compared plant fragments in the fecal pellets to the plants of that environment,” he said. “We determined the dung reflected caribou’s spring or summer diet.”
It’s possible the caribou sought out the cool temperatures of the permanent ice patch in the warmth of the Arctic summer, either for the temperature change alone or to get away from the bugs that are thicker than pea soup in that part of the world.
The permanent snowfield also yielded part of an arrow shaft which was dated as about 4,400 years old, making it a rare example of hunting technology from that era found in Canada.
Davitt has also worked on much more recent fecal material and deduced something crucial to the health of some langur monkeys in the Bronx Zoo.
As Davitt explains it, several monkeys in the Bronx had mysterious developed cases of peritonitis. The zoo sent Davitt samples of the animals’ intestinal products to check for what could be contributing to their life-threatening illness.
“The vet there at first thought it might be that the monkeys were eating rope that was in the exhibit,” Davitt said. “But monkeys have a strong sense of social order. The higher-ups on the scene got to eat the monkey food the zoo provided while lower-downs waited nervously on the side.”
That led the less fortunate monkeys to eat fronds of a plant called Pandanus utilis that was in the exhibit.
“We found the plant in the fecal material. There were microscopic crystals on the plant fibers, and those crystals were rubbing on the monkey’s intestines,” Davitt said.
That insight helped save the lives of the monkeys after the plant was removed from their environment.
“We’re just a small part of much bigger teams, helping researchers elsewhere engaged in their studies of wildlife,” Davitt said.
One simple piece of equipment in Davitt’s lab is a kitchen blender. It’s used to pulverize samples into a thin soup from which slides can be made for examination under the microscope.
“We call the product in the blender a crappé frappé,” Davitt quipped.
Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University. Peters can be reached at email@example.com.