Female elk learn to avoid hunters as they get older, making them virtually "bulletproof" to human predators, research from the University of Alberta study suggests.

The study, led by Edmonton conservationist Mark Boyce, examined elk in a 46,000-square-kilometre range stretching across southwestern Alberta into southeastern B.C.

"Elk learn to become shy as they get older," said Boyce in a statement. "The magic number is 10. After this age threshold, female elk become almost bulletproof, virtually invulnerable to hunting."

Older and wiser

Using radio collars, a team of researchers studied the movement of herds during hunting seasons between 2007 and 2012. It was clear that the cow elk of the herd get wise to the benefits of being gun shy, Boyce said.

The study demonstrates that elk can learn from the mistakes of others. Researchers believe both females and males could become savvy to hunters, but cow elk made for a better study group.

"In the males, the ones with certain behaviour all get shot, so the survivors all had different personalities. There is a selection there," said ecologist Henrik Thurfjell, a former postdoctoral fellow at the University of Alberta who took part in the research. 

"But in the female, we couldn't show that. When we started digging into the data, we learned that they changed behaviour over time so they actually learned something.

"There are a lot of males shot, so we can't really test their learning." 

Cows alter behaviour

At about 10 years of age, the cow elk monitored in the study began to change their behaviour during regular hunting seasons.

These animals would cover less ground, and remain in densely wooded and steep, rocky areas where human predators were less likely to venture.

And the animals that survive become even better at avoiding hunters each year, said Thurfjell.

They became more restrictive in their travel across the range during each subsequent hunting season. The reaction is not genetic, said Thurfjell.

Instead, the animals are learning from the mistakes of other animals which fallen prey to people.

"They become more savvy and know how to utilize the landscape and graze in low risk areas," said Thurfjell. "That we get such an effect of learning toward humans is pretty surprising.

"I was pretty sure they had some ability to learn because most animals do. But this is quite advanced, which is pretty cool."

The study has implications for wildlife protection programs, and challenges assumptions that hunters have significant impact on the demographics of elk herds, Thurfjell said. 

Their research shows that social learning, not just natural selection or selection by hunting, plays a role in elk survival.

"There are several reasons to choose elk as a study animal," said Thurfjell. "They are a species that can cause conflict.

"It really matters to people what happens with an elk population. It matters to farmers, it matters to hunters and it matters to other species, so they are quite important."

The peer-reviewed paper was published Wednesday in journal PLOS One.