deer?

Just how old are you,

deer?

Determining precise age is difficult, but there are ways

Experienced hunters often will talk of their conquests in terms of age. Proudly sharing they’ve harvested a 5-year-old doe. How do they know? Wild animals aren’t really known for keeping an I.D. on their person — uh, on their animal.

According to Iowa Department Natural Resources Forest Wildlife Research Technician Jim Coffey knowing the exact age of a deer is difficult to determine.

“A lot of times it is just guesswork,” he said. “It comes kind of through experience.” Most often the DNR classifies the age of a deer into one of three categories: fawn, yearling and adult.

A fawn is a deer that was born this past spring. Yearlings are typically 18 months old at this point and born the spring before last. Deer that are at least two years old are categorized as adults.

“There are three different ways we talk about aging deer,” Coffey said. Body structure, facial structure — specifically nose length— and teeth wear are the three indicators DNR biologists and experienced hunters use to estimate a deer’s age.

Of the three indicators, aging a deer by its teeth is the most accurate. “Being mammals, like humans, their teeth are replaced,” Coffey said.

“They’ll have their milk teeth and their permanent teeth. As a biologist we can look at a jaw bone and see (what teeth have grown).”

The most definitive way to measure, is to send a deer into a technician who will cut the tooth in half.

“It’ll leave a ring” he said, however, most hunters are not that concerned with the exact age of their harvest.

Also like humans, a deer’s nose continues to grow.

“You’ll see as a fawn they have a very short, baby-like face,” Coffey said. “As they get older they get a humped nose. You’ll see hunters talking about that, ‘Its nose isn’t as flat as other deer.’” When it comes to body structure, an older deer will have filled out.

“Look at plain of the back,” Coffey said. “If the deer is broadside and has a flat back or racecar shaped, that will also tell you about sexual maturity.” He also noted the thickness of the neck can indicate an older, more mature buck.

Despite popular belief, the antler points are not necessarily an indication of age.

“When you talk about points, that is genetically based,” Coffey said. “If you see a six-point deer at a year and half old and let him grow, he’ll just be a bigger, heavier six point buck the next year.”

While the number of antler points are not telling of a buck’s age, the mass of the antlers can be used an indicator. According to Coffey, as a buck ages their antlers gain more mass. However, just like atrophy of the body, antler mass does begin to decrease after a certain point in the growth and development of a matured deer.

The average age of Iowa’s deer population is difficult to determine largely because it is so dependent upon where the deer lives.

“It depends on the access to people hunting deer,” Coffey said of the average age. “In a park situation deer can live to about 10 to 12 years old.”

Coffey noted the popularity of hunting in Iowa.

“Because we persecute our deer, we’re going to shoot a third of our deer in Iowa,” he said. “But by in large, most of the deer are harvested in the three to four year old range.”

Coffey describes the number of deer as tapering as they age.

“Typically, a lot of the dear are young of the year,” he said. “Think of it as a type of a pyramid. Each year you go up, there are fewer and fewer deer.”

This pyramid helps to explain the status of a “trophy deer.”

“Only about 5 percent get to that age to be considered a trophy class age,” Coffey said.

By Amie Johansen amie@charlescitypress.com