Ya Ha Tinda elk on the decline
Tuesday, Mar 27, 2012 06:00 am
A long-term study by university researchers has found that the Ya Ha Tinda elk population is in decline.
University of Alberta professor Evelyn Merrill shared the results of this study at a Ya Ha Tinda information session organized by Banff National Park on March 9 in Sundre.
Merrill, together with Banff National Park monitoring ecologist Jesse Whittington and Banff National Park fire and vegetation specialist Jane Park, spent the evening explaining and sharing the results of their research and management projects.
While Whittington’s and Park’s projects were about Banff National Park, Merrill has spent the last 11 years studying the elk herd at Ya Ha Tinda.
“It is a system that goes all the way from grasslands that are rare to ungulates that I am very interested in, to predators,” said Merrill.
“I got involved because it is a rare fescue grassland. It was an important elk herd, and still is. It’s also a historic site.”
Merrill and her team have discovered that after increasing in the mid-1990s, the herd is now decreasing.
“If we try to understand why this pattern occurs, we can associate certain facts, although we can’t really say for sure these facts were related to this,” she said.
For example, in the early 1970s, people stopped hunting cow elk in the area. However, wolves returned to the park in the early 1980s. Then, around 2000, after researchers raised concerns over the range conditions, some animals were translocated to other areas.
“Since that time, the herd has decreased, but there are also others things that have been going on, like adverse conditions,” said Merrill.
“Recently, we have had some fires. All of this makes for a very dynamic system.”
In the early 2000s, Merrill and her team jumped at the chance to study the Ya Ha Tinda elk herd.
“The question of research that we were interested in was there some thought that we were losing the migratory behaviour of the elk at Ya Ha Tinda,” she said.
“They used to migrate into Banff all the way from 25 to 50 km in there.”
The scientists also wanted to research the effect of the resident herd on the ranch’s fescue grasslands.
“What would that growing herd do, would it eat down the vegetation, would it actually deteriorate the range?” said Merrill.
Moreover, the team wanted to study the impact of the wolves on the herd.
“Even further, since wolves had re-colonized Banff, we now had a predator-prey system,” said Merrill.
“We were interested in how these dynamics occurred.”
After 11 years of study, the researchers did find out that the ratio of migrant elk to resident elk is declining, from a 12:1 ratio 30 years ago to 3:1 in the early 2000s.
At the beginning of the project, Merrill and her team hypothesized that migrant elk have an advantage over resident elk. By migrating into Banff National Park for the summer, they are exposed to higher-quality forage and less predation, since wolves den at lower elevations.
However, the scientists learned that resident elk were using refuges associated with human activities.
“These were refuges because the wolves would not get into those areas,” said Merrill.
“They would avoid them because of the humans.”
Regardless of these advantages, the migrant to resident ratio and the herd size keep decreasing.
“The population seems to be pretty low, at about 350 animals. We are actually finding a decline in the population,” said Merrill.
“Now, we have an even number of migrants and residents.”
Towards the end of the research project, Merrill and her team discovered that some of the migrant elk are spending the summer in an area east of Ya Ha Tinda.
“Maybe there is a new migration route developing and the animals are moving off in a new direction in the summer,” she said.
Merrill hopes to access new funding to keep studying the Ya Ha Tinda elk herd.