New study looks at sustainability of feral horse population
Amid concerns about a potential boom in the feral horse population — and the land’s ability to support them — a new study of the famous equines has been undertaken in Alberta’s Foothills.
Paul Boyce, a PhD student at the University of Saskatchewan, aims to collect new, valuable data on the population and determine the carrying capacity of the land for the animals.
“We hope (the data) will inform the management strategies moving forward,” said the student, who first visited the Sundre area about five months ago and spent his first six weeks of field time in the area in July and August.
The study is important, as Alberta Environment and Parks (AEP) spokesman Jamie Hanlon notes the increase of horses from 2013 to 2017 was 222 animals, not counting horse captures in 2014 and 2015.
“Other jurisdictions have seen unmanaged populations double in four years until resources become limiting,” Hanlon said. “Longterm population trend lines, and the yearling-to-adult ratios, show that Alberta may be experiencing this kind of exponential growth.”
Hanlon added that the landscape occupied by horses is grazed yearround, allowing no time for recovery. He said as feral horses are unmanaged, they create “a significant challenge to a balanced approach to land use.”
Hanlon said one of the challenges of continual grazing is the increasing density of invasive species, such as Timothy, Kentucky bluegrass and smooth brome, which can displace native species.
Boyce’s five-year project, which is under the supervision of Philip D. McLoughlin at the U of S department of biology, is independent, but intended to inform the work of the Wild Horses of Alberta Society (WHOAS). He aims to learn how dense of a feral horse population the land is able to sustain.
WHOAS is part of an advisory committee — which also includes outfitters, ranchers, veterinarians, conservation groups and rangeland experts — that helps the province deal with the management of the horses.
The non-profit began a contraception program in 2015, vaccinating mares with a birth control named porcine zona pellucida released from a dart gun. Its contraception program is about halfway into a five-year memorandum of understanding with AEP.
Hanlon said if the five-year study determines the birth control is effective in individual horse population management, “this option may be considered for larger-scale application.”
Although this method has been used in other wild horse populations, Boyce and WHOAS understand the distinctiveness of the Foothills environment.
“This is a pretty unique population, in that there are a lot of natural predators here, so you might expect the natural mortality to be higher,” Boyce said. “These are animals that have been feral or wild for a while now, and how they interact with predators and the predators interact with these horses is quite an interesting dynamic.”
Hanlon said environmental conditions do affect counts year-to-year, but it’s important to look at “multi-year trend data and yearling ratios.”
The study will help determine the survival rates of foals and adults.
“This contraceptive program is a positive way to avoid culling,” said Boyce, noting the previous practice to capture and sell some of the horses, some to slaughter, is less “socially acceptable” than birth control.
Boyce will also study the affects of a variety of land uses in the Foothills, from industry, forestry and recreational, to livestock and wildlife.
Dr. Bruce Stover, veterinarian and member of the board of directors of WHOAS, said counting methods of wild horses have improved and populations migrate between zones.
There are currently 82 horses vaccinated with the birth control, and Stover said WHOAS’ contraceptive program data compares to other projects with the same birth control. About 80 per cent of mares vaccinated with one shot of the vaccine will not have a foal the following spring, but may produce one in the next year or two.
Stover said WHOAS’ program isn’t intended to manage the population at this point, as the carrying capacity of the land is unknown, something to be ascertained by Boyce’s research.
In the meantime, Stover said WHOAS has catalogued 90 per cent of the wild horse population in the Foothills, and put the data into a mobile app used by volunteers on a tablet.
A volunteer in the field can list traits of a horse to narrow the search to a few horses fitting the description, which are accompanied by photos.
Leo Raymaakers has been photographing the horses for WHOAS since he joined in 2013.
“Our (goal) is to try to protect and preserve them for future generations,” Raymaakers said. “They’re such a gorgeous animal, and to see them out in the wild is just amazing.”
Stover doesn’t believe the horse population is in crisis, but is open to management of the animals.
“We want to do what’s best for the horses,” he said.