Wednesday, September 7, 2016

Elk Vulnerability: Secure Habitat Protects Healthy Herds and Hunting

Photo by Dave Stalling
Forty-five years ago Alan Christensen went elk hunting with his uncle and some friends. Though more than a foot of snow had fallen, the elk stayed up high, out of reach. “But my uncle was a logger and had the only four-wheel-drive around,” Christensen says. “That got us into the high country where the elk were, away from other people.”

Today, four-wheel-drive trucks are standard equipment for most hunters.

“The technology and ability for people to get to and kill elk has changed dramatically in 45 years,” Christensen says. “That, combined with changes in habitat, more hunting pressure and better access to elk country have made elk more vulnerable to hunting.”

As a former Wildlife Program Leader for the U.S. Forest Service’s Northern Region, Christensen not only helped pioneer the concept of elk vulnerability, he did something about it.  In 1989, he joined with other wildlife professional from state and federal agencies, universities and timber companies to form an Elk Vulnerability Working Group. Through research, symposiums and publications, the group united biologists and managers to identify vulnerability problems and seek solutions.

In one major study, researchers examined elk mortality in areas with a high density of open roads, another where roads are closed to motorized vehicles during hunting season, and another area with no roads.  In the area with open roads, only five percent of all bulls lived to maturity (defined as 4-1/2 years). None of the bulls lived past 5-1/2, and the herd contained about 10 bulls to every 100 cows. In the area with seasonal travel restrictions, 16 percent of the bulls lived past maturity, most reaching 7-1/2, with 20 bulls per 100 cows. In the roadless area, 30 percent of the bulls lived to maturity, most reaching 10 years, with nearly 35 bulls per 100 cows. 

“As road access increases and habitat security declines, we can expect elk to be increasingly vulnerable to hunting,” researchers concluded. “Without access management, the results will include elk populations with undesirable sex and age structures, increasingly complex and restrictive hunting regulations to protect elk herds, and a loss of recreational opportunity.”

Other studies showed similar results.

“Vulnerability encompasses many factors,” Christensen says. “Densities of roads open to vehicles, increasing density of hunters, decreasing amounts of elk cover, improved technology . . . taken by themselves they may not be that significant, but put them all together and they’re very significant.”

Significant enough that in many elk states, rising elk vulnerability spurred wildlife departments to cut hunting seasons and switch more and more to limited-entry hunting.

“As a whole, elk populations are generally stable or increasing throughout Montana and the West,” Christensen says. “There are more elk now than at any point since the turn of the century. However, in some herds the problem is the sex ratios and age-class structures – in other words, a lack of mature bulls. This is not so much an elk vulnerability issue, it’s a bull vulnerability issue.”

Some hunters are happy to hunt for cows, spikes and raghorns. For them, the opportunity to hunt elk ranks higher than the opportunity to encounter a mature bull in the field. Until relatively recently, even some wildlife biologists believed mature bulls weren’t necessary, as long as young bulls bred with cows. They judged the health of herds through pregnancy rates and annual “recruitment” of newborn calves.

But numerous studies have since confirmed what many wildlife biologists already suspected: Lack of mature bulls in a herd can disrupt breeding seasons, conception dates and calf survival.  Younger bulls tend to breed later and over a longer period in the fall than mature bulls. As a result, calving seasons last longer and many calves are born late in the spring. Late-born calves miss out on the lush forage of early spring, and also have less time to feed on high-quality forage and consequently may enter the winter in poorer condition than calves born earlier.  Drawn-out calving seasons also make newborn elk more susceptible to bears, mountain lions, coyotes and wolves. When calving seasons are shorter, as is the case when mature bulls do the breeding, calves are all born around the same time. This “flooding strategy,” as biologists call it, overwhelms predators and allows more calves to survive.

Perhaps even more important, though less clearly understood, mature bulls maintain social order in a herd. The presence of mature bulls reduces strife, exhaustion and wounding among bulls and frees cows from unwanted advances by socially inept young bulls – helping elk save crucial energy that can be a matter of life and death during a harsh winter.

“Fish and wildlife agencies, and the federal land management agencies, want to maintain opportunities for hunters,” Christensen says. “But we also have an obligation to maintain healthy wildlife populations – which includes keeping a good ratio of mature bulls in the elk herds. People want healthy elk herds, but they also want access to elk and high hunter success rates. We can’t have it all. There are too many people and finite resources. Part of the solution is to get maintain good habitat security, get a handle on roads and make it less easy for hunters to get into elk country and shoot bulls.”

Thanks in large part to the leadership and efforts of Alan Christensen and others who participated in the Elk Vulnerability Working Group, land and wildlife managers developed standards to incorporate into management plans, ensuring protection of habitat security to reduce vulnerability and maintain healthy elk herds and hunting opportunity.  But some managers seem to be forgetting the history and the science.

The Helena-Lewis & Clark National Forest (HLCNF) recently amended its Forest Plan, replacing the current wildlife security standard with a new standard that removes all traditional and measurable components of secure habitat.  

“A lot of time, effort, cooperation and good, solid science went into understanding habitat security and elk vulnerability, and developing reasonable standards that help us maintain healthy habitat, healthy elk herd, and public hunting opportunities,” Alan Christensen says. “It’s a proud part of Forest Service history. We need to stick to the science and maintain these standards.”