Neither do lions, bobcats, raccoons, elk or deer.
So when biologists from points around the globe want to know just how old critters are, they often turn to a small laboratory nestled up against the hill in the tiny town of West Riverside.
“Not many people know that mammal's teeth grow throughout their lives,” Matson said. “If you slice a tooth thin enough, you can count the growth rings just like the rings in a tree.”
Matson finds those rings just inside the roots of the tooth in a layer called the cementum. Peering through a high-powered microscope, Matson and others at his laboratory spend long hours carefully counting the rings in thousands of teeth each year.
Earlier this week, Matson had hundreds of red deer jawbones from Spain spread out on a table in a back room waiting to be processed. A large cardboard box was filled with small envelopes containing 2,260 moose teeth from New Brunswick. Other boxes held the teeth of a wide variety of other critters from around the world.
The information Matson's eight-person crew gathers is used by researchers and biologists to determine just how well wildlife populations are faring.
Montana Fish, Wildlife and Parks biologist Bob Henderson has been using Matson's service for years.
“When the sample size is large enough, this kind of age information gives biologists some very good clues about which direction the population is going,” Henderson said.
If a biologist finds there are lots of young animals in the sample, it's a good bet that the population is growing. But when the population is filled with mature and older animals, biologists might start considering different management plans to add younger critters to the mix.
“Information about age is just one of many pieces of the puzzle a biologist uses to help determine what kinds of management that might be deployed to maintain that population,” he said. “It is an important piece of the picture.”
An animal doesn't necessarily need to be dead to offer a tooth for science.
“It's not like it is major surgery when you have to extract a tooth,” said Henderson. “Bears, for instance, have this small pre-molar right behind their canine teeth, which has a pretty straight root.
“With a tooth extractor - just like the one your dentist uses - you can pop that little tooth out of there in 5 to 10 seconds. I doubt the bear even knows that little tooth is missing.”
Large carnivores aren't the only beasts that wake up in the morning missing a molar.
In the eastern half of the country, biologists have been baiting raccoons with tasty treats laced with an oral vaccine for rabies and a healthy dose of tetracycline.
Over the last couple of years, biologists have been capturing raccoons after the critters have had a chance to snack on their carefully placed baits. They yank out a tooth and send it on to Matson's lab where the molar is sliced ever so thin and placed on glass slide.
The tetracycline glows bright under a touch of ultraviolet light - easily spotted by a trained eye.
“They're trying to assess the effectiveness of their vaccination program,” Matson said. “It turns out that a lot of raccoons have taken the bait ... up to 30 percent of the animal's teeth show the tetracycline marker. It's really nifty.”
Not every part of Matson's business is so black and white.
“There are individual variations as well as variations between species,” Matson said. “The cementum isn't always deposited uniformly Š in black bears, for instance, there can be two lineal lines deposited every year.”
Matson's also noticed that female bears' teeth don't grow as much while they're raising cubs. That information can play a role in helping biologists manage the elusive beasts.
“Predators, like bears and mountain lions, are very difficult to census,” Henderson said. “Getting ages from hunted animals is a relatively easy thing to do. It gives you clues about what's happening with that population.
“Almost every state in the West extracts teeth from predators to gather that important information,” he said.
Matson's laboratory has gained a reputation of putting together just the kind of information biologists and policymakers can use to develop long-term management for a variety of wildlife species.
Among the first big breaks Matson had in establishing his credentials came after the Defenders of Wildlife sued the state of California over its management of bobcats.
For several years, California sent Matson's lab about 25,000 bobcat teeth annually to be aged.
“The information we gathered showed that California had lots of bobcat habitat and lots of bobcats,” Matson said. “They used that information to justify the continuation of their bobcat season.”
The process of aging a tooth isn't simple, especially when you consider that the number of teeth Matson's laboratory processes every day.
“We estimate that it takes us about 11 minutes per tooth through the whole process,” Matson said. “We try to do 300 to 400 teeth a day.”
Every single tooth is carefully catalogued and tracked throughout the entire process which begins with a hot water bath that loosens the grime and bits of tissue still attached to the root.
A technician uses a mesh material to scrub each tooth before packing it inside an individual container. From there, the tooth goes through a series of acid and water baths to decalcify it, followed by soakings in alcohol and finally paraffin.
Imbedded in a paraffin block, the tooth is sliced paper thin and mounted on a slide. Following a few more dips in different chemicals, the paraffin disappears and the section of tooth is dyed a deep blue.
“Once we get to that point, we're ready to count the rings,” Matson said. “It's a very labor-intensive process. Since we have so many teeth to do, it has to be done in a production line like manner. It's taken us quite a few years to get the process to this point.”
Matson's business began in a roundabout way years ago.
After graduating from the University of Montana in 1969, Matson decided he was going to find a way to put his love for histology to work. He collected a bunch of different tissues and carefully mounted them on slides. Matson put together a catalogue of his efforts and sent them out to schools.
“And then we waited to see what would happen,” he said. “A friend of mine was in wildlife and he realized we were starving to death. He told about this technique to age animals from thin slices of a tooth.”
The couple put together some mimeographed postcards touting their new business and crossed their fingers.
“Word got around pretty fast and our business began to grow,” he said.
It grew large enough that Matson decided they needed a laboratory. With $500 in his pocket, he went to Rangitsch Brothers and bought a 8-foot-by 28-foot trailer house.
It wasn't perfect, but it was a start.
“The roof leaked, the floor was rotten and it was always cold,” Matson said. “We built this place in 1986 and I've been warm ever since. ... We believe we've found a special niche. We're the only commercial lab doing this kind of work that we know of.”
Among the current orders at Matson's lab are red deer jaws from Spain. Only two incisors from each jaw will be tested.
Reporter Perry Backus can be reached at 523-5259 or at pbackus@missoulian.com.
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