Once female elk make it to 9 or 10 years old, they hardly ever fall prey to human hunters — and Henrik Thurfjell of the University of Alberta, Canada wanted to know why. “I’m fascinated by how we humans fit in as a species among other predators,” he says.
Elk are extremely gregarious and can live upwards of 20 years. So Thurfjell wondered if the combination of sociability and long lifespans gave them the opportunity to learn from experience, including the misfortune of others that did not survive a hunting season.
In new research published in PLOS ONE, Thurfjell and his colleagues showed that his hunch was right. The team used GPS collars to track 49 female elk in Alberta and British Columbia over two hunting seasons. The data they collected included how far the elk traveled with time as well as when they stuck to safer grounds, such as rugged terrain, which has steep slopes that impede hunters, and forests, which provide cover.
The researchers found that individual female elk adjusted their behavior with age, suggesting that they learn to avoid hunters. Older female elk moved less during hunting season, making it harder for hunters to spot them. Older female elk also favored rugged terrain and forests when near roads, where they are easiest to spot.
Interestingly, the researchers discovered that elk can differentiate between bow hunters and rifle hunters: the animals stuck to rugged terrain more often during the season for the former than that for the latter. How? “Probably by observing the behavior of humans,” Thurfjell says. “Bow hunters use different tactics, like stalking really close or hiding and waiting, probably resulting in more disturbances than actual shots. Rifle hunting season draws more hunters to the woods and they move around more.”
Since elk can learn from experience, it’s likely that other social animals can too. “My guess this is something all group living mammals have the potential for,” Thurfjell says.
This work could help managers tasked with keeping wildlife away from crop fields. “Instead of reducing the population extensively, or using rather ineffective deterrents such as sound, a viable option may be to infrequently shoot single individuals of larger groups so those fields are associated with high risk,” he explains.
Do elk also learn to avoid non-human predators with age? Thurfjell may find out. He is now studying how wolves and other predators affect elk behavior.
Reference: Thurfjell H, Ciuti S, Boyce MS (2017) Learning from the mistakes of others: How female elk (Cervus elaphus) adjust behaviour with age to avoid hunters. PLoS ONE 12(6): e0178082. https://doi.org/10.1371/journal.pone.0178082
Image Credit: Mark Boyce