Droppings of Mammoth Proportions

By Lilian T. Hoffecker
Photos by Dr. Larry Agenbroad/The Mammoth Site

Light snowfall chilled the air as two paleontologists, Dr. Jim Mead and Dr. Larry Agenbroad, entered an immense cavern in southern Utah. They came here after seeing samples of an interesting substance that park workers had found in the cave.

Bechan Cave is big enough to shelter a herd of mammoths.

With anticipation, they dug into the floor. Under a few feet of sand, there it was: a thick layer of matted plants that looked and smelled like hay. It was an exciting and important find. These scientists study mammoths, and what they had found was mammoth dung.

Ice-Age Elephants
Mammoths were elephants. They were creatures of the Ice Age, which began about 1.6 million years ago and ended about 10,000 years ago.

The Columbian mammoth was the most common kind in what is now called North America. It roamed the western plains while the smaller woolly mammoth lived in Alaska, northern Asia, and Europe. In North America, the mammoths vanished near the end of the Ice Age.

Scientists do not agree about the way the North American mammoths went extinct. Were changes in the climate and environment too much for the mammoths? Did people hunt the mammoths out of existence? Or did a combination of the two—the changing world and human hunting—wipe them out?

To answer their many questions, scientists study the remains of mammoths.

On that wintry day, Drs. Mead and Agenbroad knew they would find ancient dung—but in what condition and how much?

Over several visits, the scientists and their assistants dug pits and narrow holes in the cave floor. It was no small job because the cave is fifty-seven yards long and thirty-four yards wide. That's big enough to hold about twenty-four big tractor-trailers—three rows of eight trailers parked side by side.

“Big Dung” Cave
Under the sandy floor, a layer of dung four to sixteen inches thick covered the cave floor. There was enough here to cover a basketball court with a layer more than two feet deep! The scientists named the cave “Bechan” (bay-chawn), which means “big dung” in Navajo.

Some of the dung was in excellent condition. The air in the cave had dried it, preserving it almost perfectly. The mat also included droppings from many different kinds of animals. Most of the material had been trampled and mixed together, making it hard to tell which sample came from which type of animal.

Grass fibers and other clues are well preserved in this big dung ball.

But a few whole balls of dung rolled out as the scientists excavated the pits.

Who Was Responsible?
Were these balls really mammoth dung? Horses, camels, deer, ground sloths, and many other animals shared this region with the Columbian mammoths.

Size alone eliminated many animals. The dung balls in Bechan Cave are as large as bowling balls, and most animals have considerably smaller droppings.

Another clue was the hair. The strands found in the dung balls closely matched hair of woolly mammoths found frozen in Russia. Also, the only other big plant eater of that time—the Shasta ground sloth—chewed its food so well that the plants were chopped into fine bits. The grass in the Bechan Cave dung balls was coarse, with long fibers much like the fibers in elephant dung.

By studying these big dung balls, the scientists learned how to tell mammoth dung from other kinds. Then they studied samples from throughout the cave, and discovered that most of the dung had come from mammoths.

Mammoths' dung holds clues about their world.

Under the sandy floor of Bechan Cave, scientists found a mat of dried dung.

Paleontologists have learned much from the leavings in Bechan Cave. Using special techniques to determine the age of the dung, the scientists learned that the mammoths roamed in and out of the cave roughly between 12,000 and 13,000 years ago. Mammoths left these droppings over a period of about 1,000 years.

That means the mammoths did not come to the cave often. An African elephant can drop two hundred to three hundred pounds of dung per day. It makes sense that a herd of the even larger Columbian mammoths could easily have left the quantity of dung in Bechan Cave in just a few seasons.

The Mammoths’ Diet
Analysis of the plants in the dung showed scientists exactly what the mammoths ate. Not surprisingly, the diet was mostly grasses. After all, like the teeth of modern elephants, their teeth had squiggly ridges that were useful for crushing and grinding tough grass stems and leaves.

But the dung samples showed that mammoths ate more than just grasses. The scientists found pieces of sedge (a wetland plant), birch, spruce, rose, sagebrush, and even cactus spines.

The scientists say this combination of wetland and desert plants is a sign of a mixed environment, probably a large, dry area with a few rivers that created places where wetland plants could grow. In fact, a similar habitat still exists today in the mountains near Bechan cave.

Dr. Mead and Dr. Agenbroad feel lucky. Not many paleontologists have the chance to catch such a vivid glimpse of the lives of long-gone animals. They hope another big-dung cave will be discovered, along with the wealth of information it would provide.