Jim Magowan/Turnagain Times
By Jim Magowan
Turnagain Times Correspondent
Wildlife biologists and managers deal with the “laws of nature” on a daily basis. We are all familiar with two of them: Murphy's Law (Anything that can go wrong will go wrong; at the worst possible time, and the law of unintended consequences, “I didn't expect that to happen!”
Wildlife and habitat management are particularly subject to Murphy's law and unintended consequences because the relationships between living things—including humans—are so complex and variable.
The key to warding off unintended consequences is gaining enough understanding and knowledge about environmental systems to recognize more of the potential consequences to avoid the bad and achieve the good.
If mosquitoes were eradicated from northern Alaska fishermen wouldn't have to tolerate them, but, of course, there wouldn't be any fish to catch because they feed on the mosquitoes.
To avoid throwing out the trout with the mosquitoes, the U.S. Forest Service conducts extensive studies of an area's ecosystem before it begins work to “improve” it. The idea is to assure that Murphy doesn't turn improvements into unintended disasters.
Thus it was that this past summer Mary Ann Benoit, a wildlife biologist for the Seward Ranger District, was trekking through the forest along Palmer Creek Road in Hope playing recordings for what she hoped was an audience of Northern Goshawks.
Benoit was conducting a wildlife survey on an area where the Forest Service is involved in a wild fire protection program and a habitat improvement project. If the Forest Service inadvertently evicts forest dwellers, such as the Northern Goshawk, from their nesting or hunting grounds, the goshawks certainly wouldn't consider it a habitat improvement and the Forest Service probably wouldn't either.
“I was checking to see if the area was occupied by Northern Goshawks,” said Benoit as she explained her research methodology. “The hawks will often respond to the broadcast calls. Surveys are done by walking a grid in the forest while broadcasting calls. If we see a hawk or if a hawk answers the recorded calls, we search the area for a nest. Even if a hawk responds, it does not necessarily mean a nest is in the area. It may just be part of the hawks hunting territory.”
Broadcasting calls is a more productive way to locate goshawks than just trying to spot them visually. The odds of spotting nesting hawks, if the biologist is in a nesting area, are better than the odds of spotting a more transient hunting hawk, but, even so, the odds of spotting a hawk are far less then the odds of them hearing and responding to the recorded calls. Calling greatly improves the odds of locating a nest site and increases the likelihood of identifying hunting territory even more.
“Active goshawk nests are protected by preventing continuous disturbances within 660 feet of the nest,” Benoit said as she described the measures taken when goshawk nests are found to protect the nests (cutting and burning are not permitted near the nests during nesting season March 1-July 31).
Because goshawks often use the same nest or nesting area from year to year, a nest site is protected until it is abandoned. A site that is not used for several years is considered abandoned.
Benoit described how decisions about habitat protection can involve complex relationships among multiple factors. Fuel reduction by the clearing and burning of spruce bark beetle killed trees may disturb nesting hawks, but fire can be a much worse disturbance to the hawks as well as a risk to people. Both potential consequences must be considered in improving habitat. The key is balance—try to balance the factors to come up with the optimum environment for hawks as well as for people.
Good nesting habitat can also be a high-risk environment for fire.
“Goshawks prefer high trees such as cottonwoods for nests with a dense canopy overhead and an open understory,” Benoit said. “This is an environment that can contain a lot of standing fuel for fire.”
Benoit described one way the Forest Service tries to balance the potentially opposite aims of eliminating fire hazards and improving goshawk-nesting habitat. She said they do selective thinning to favor big trees for nesting with the dense canopy goshawks prefer for protection and the open understory for hunting.
The call broadcasts were specifically to locate goshawks, but, the surveys do not ignore other species. Biologists try to develop a picture of the entire spectrum of wildlife in an area, from large animals such as moose and bear to songbirds, because projects such as the one in Hope fuel reduction and habitat improvement can affect everything that lives in or uses the area.
For example, because habitat improvement also involves restoring streams to provide better fish habitat, bears eagles and humans might also benefit from the improved habitat.
And when the survey concluded, how many goshawks did Benoit find in the area?
“None,” she answered. “Maybe some goshawks will move into the area after the habitat improvement is completed.”
