Hunting pressure not causing evolution of smaller Alberta bighorn sheep: study

A new study indicates trophy hunters aren’t causing Alberta’s bighorn sheep to evolve into something smaller and less impressive.

EDMONTON — A new study indicates trophy hunters aren’t causing Alberta’s bighorn sheep to evolve into something smaller and less impressive.

Previous studies have found that the average horn size of a six-year-old bighorn has decreased by about three centimetres over the last 30 years.

Scientists have suggested that’s because hunting pressure is causing a kind of reverse natural selection — as hunters continually take out the biggest males in a herd, smaller animals have more chances to reproduce and pass along their DNA.

But new research in the Proceedings of the National Academy of Sciences has concluded that inheritance isn’t a big deal when it comes to size.

“Body mass is only weakly inherited,” said Lochran Traill, a biologist at Imperial College in London.

“Thereby, any evolutionary response of the targeted trait to hunting is negligible.”

Traill and his colleagues used a combination of field data and mathematical modelling to tease out how different factors influence the overall state of the iconic alpine ungulate, Alberta’s provincial animal.

It turns out shrinking horn sizes from the bighorn hunt aren’t due to any unseen biological effect. Animals with big horns are rarer simply because hunters shoot lots of them.

“Any shift in the distribution of body mass among males is demographic,” Traill said. “Changes are largely driven by the removal of larger animals

“There are simply fewer males.”

That means that the number of big males with fully curled horns could easily rebound if they weren’t targeted as much.

“Any decreased frequency of hunting will simply mean that fewer large males are being shot, and thus the likelihood of large males being found in the population may increase,” said Traill.

He pointed out that letting big males breed is also good for the overall health of a herd.

“It will always be better to let males in their prime breed,” said Traill, who added it remains “prudent practice” to target older males “past their mating prime.”

Alberta Environment is examining its hunting regulations around bighorns to try to determine if adjustments need to be made to improve stocks.

“We are in the process of completing a new management plan for bighorn sheep,” said spokeswoman Carrie Sancartier.

“Once that is completed there is expected to be a public discussion that will include harvest.”

Just Posted

Child’s play at Westerner Days

Balloons bring out the child in everyone

‘Do Indians have property rights?’ Former Alberta chief’s land dispute in court

STANDOFF, Alta. — A dispute between two families over land on Canada’s… Continue reading

Missing female found near Sundre

Local rancher finds missing female

Buyers turn to letters to snag homes in Canada’s hot real estate markets

TORONTO — Monica Martins and her husband had been looking for a… Continue reading

WATCH: Gazebo groundbreaking in Waskasoo

Fifty per cent of the $100,000 project is funded by a provincial government grant

Second World War Two-era B-29 Superfortress named ‘Fifi’ lands for first-ever Canadian tour

MONTREAL — A rare Second World War-era bomber named “Fifi” has touched… Continue reading

Magnus Cort Nielsen wins Stage 15 of Tour de France

CARCASSONNE, France — Magnus Cort Nielsen of Denmark sprinted away from two… Continue reading

Ryan Reynolds teases ‘Deadpool 2’ extended cut at Comic-Con

SAN DIEGO — Ryan Reynolds has made a triumphant return to San… Continue reading

‘Wonder Woman,’ ‘Aquaman’ and ‘Shazam!” thrill Comic-Con

SAN DIEGO — Warner Bros. brought out all the stops Saturday at… Continue reading

All shell, no shock: Lobster prices strong, season picks up

PORTLAND, Maine — New England’s lobster industry faces big new challenges in… Continue reading

Woman killed in collision near Olds

A woman is dead after a collision west of Olds Saturday afternoon.… Continue reading

Evacuation numbers remain at nearly 1,000 as B.C. wildfires rage on

SUMMERLAND, B.C. — Officials in British Columbia’s Okanagan region hope that fire… Continue reading

Survivors recount deadly Missouri duck boat sinking

BRANSON, Mo. — “Grab the baby!” Those were the last words Tia… Continue reading

Most Read


Five-day delivery plus unlimited digital access for $185 for 260 issues (must live in delivery area to qualify) Unlimited Digital Access 99 cents for the first four weeks and then only $15 per month Five-day delivery plus unlimited digital access for $15 a month