Fire a boost to moose
While the Yukon grapples with devastating forest fires and fire crews muster considerable resources to protect people and property, at least one animal is likely to reap the benefits of the wildfire season.
 |
|
Moose tend to adapt well to forest fires and their aftermath.
(photo: Environment Yukon)
|
"Moose are particularly well adapted to the early stages after a fire when the vegetation tends to grow back in abundant willows and other browse," says Yukon government moose biologist Rick Ward.
"Willows are one of its key food species, so fires generally mean better habitat for moose. Fires release nutrients and expose mineral soils so seeds can take hold, and the loss of the canopy lets in lots of light so willows come back quickly."
Moose populations are notorious for spiking in burned areas in the years immediately following forest fires. But the 2004 fire season has been anything but typical, so no one is willing to speculate yet on what the effects of such extensive burning could be on wildlife.
"Fire is one of the switches that set the system back to zero, resulting in fresh young vegetation. A lot of species tend to do well in the early stages after a fire."
"But it's a fairly complex, dynamic system, so how much a fire will benefit moose really depends on a number of factors," says Ward. "Areas that were good moose habitat before the fire will generally come back even better after a fire. Other areas may never be good moose habitat. Things also tend to come back more slowly after very hot fires."
One factor that Ward suggests may contribute to the moose's success is that it is well equipped to handle the forest fires and their after-effects.
"They're pretty good at staying ahead of fires. A moose can move 10 km in an hour, whereas if a fire moves 10 km in a day that's pretty radical fire behaviour," he says.
After a fire, moose may be able to move through the downed trees and debris better than their predators.
Wildlife biologist Bob Hayes suggests that moose success may be related to the species' readiness to move. He points to an apparent shifting response of moose to a large fire in the Mayo region in 1992.
"The population nearby increased sharply, and the increase was probably due to an influx of moose from the recently burned area," says Hayes. "Smaller mammals can't escape, whereas moose can. They're smart and they can adapt -- they know the area where they live very well, they know where to find water to escape fire."
"But the scale of what's happening this summer is phenomenal, and I wouldn't know what it's going to do."
Building on a theory suggested by Yukon biologist Alan Baer, Hayes does wonder if the moose's predators are at a disadvantage during fire season, resulting in higher calf survival.
Bears are prime predators of moose calves, and they use scent to find prey. If fires occur during the first month when calves are vulnerable, Hayes suggests that smoke probably makes it harder for predators to follow scent, especially grizzly bears which are responsible for most of the predation on newly born calves.
"If there's a fire in June, there may be a real advantage to calf survival because the cow and calf can't escape predators easily," he says. "If the calf can get through its first month, then bears have a harder time catching them."
Both Ward and Hayes see an important role for fire as an ecosystem management tool.
"Society has fairly human-centred reasons why we'll let a particular forest fire burn or fight it. The highest priority is always to protect human life and property, but as wildlife managers we're interested in the effects of fire from a species management perspective," says Ward.
"We often see forest fires as a good thing from a moose management perspective."
"But my interests as a moose manager may run counter to the interests of other species managers. The caribou biologist may see an area as very important wintering habitat for caribou, and if it takes fifty years for the lichen to recover after a fire that may not be good for caribou."
Fire management staff often include Yukon biologists in their fire suppression planning, and Ward says he's sometimes asked which fires are more strategic from a moose habitat perspective.
In a bad fire year, Ward's desire to see an area burn to benefit moose falls off the priority list quite quickly. He knows he's not going to hear from an overworked fire management team that has the protection of people and property at the top of the list.
Hayes and colleagues working on Ddhaw Ghro Habitat Protection Area planning are looking at creating fire management plans that factor in the region's vulnerable Ethel Lake caribou herd.
"We want a fire management plan for the area that responds to the needs of wildlife populations," he says. "Small caribou herds in the central Yukon have already taken a hit from past fires. It's a real concern when you have a small, vulnerable caribou herd with little ability to absorb the loss of important winter range to wildfire."
- For more information about moose in the Yukon, contact Rick Ward at (867) 667-5787.
- Find out the latest about Yukon wildfires online at www.gov.yk.ca/depts/community/firemanagement.
