Wednesday, August 20, 2008

Guest editorial — Objectivity should trump advocacy in predator control ballot measure

Whether you favor or oppose predator control, with or without aerial shooting, the state’s juggling of this political hot potato warrants concern about its respect for democratic process and scientific integrity.

Twice before, Alaskans have voted against aerial shooting of “predators.” Twice before, the state has derided the vote as “ballot box biology.”

As voting on a new initiative approaches, Board of Game members have toured Alaska communities arguing that aerial shooting is essential for reducing predators enough to achieve target moose and caribou harvests. Intensive management, they claim, is the only strategy justified by the scientific evidence.

Really? Biologically, do predator numbers actually have to be drastically reduced to restore balance with their prey? Is aerial hunting essential to achieving this? Politically, are Board of Game presentations and literature educational or propaganda that illegally lobbies against the Ballot Measure 2?

True education explains how key statistics were derived. It gives a hearing to all sides of an issue. The Board of Game does neither. It ignores most concerns of the National Academy of Sciences in its report “Wolves, Bears and Their Prey in Alaska,” as well as more recent information on predator-prey ecology – information suggesting that intensive management could backfire, adversely affecting moose and caribou.

1. The Board of Game proposes restoring moose and caribou numbers to their habitat’s carrying capacity (“K”). Is that wise? Populations near K are especially vulnerable to disease, malnutrition and predation; sustainable yield is low. Health and yield are maximized near 50 percent K. So why isn’t 50 percent K the board’s target?

2. The board claimed that predators take up to 80 percent of all moose and caribou dying.
Under what conditions? How much is nonhunting mortality governed by predator abundance versus environmental conditions (like snow depth)?

Isn’t 80 percent a worst-case scenario? What’s the average percent eaten by predators? Under what circumstances?

How many of the prey eaten are killed by predators, rather than by malnutrition, winter severity, etc?

3. Of prey killed by predators, how many are “walking carrion” that would have died anyway? What proportion of prey spared from predation would be available for hunter harvest? Implying anything near 100 percent is comic book biology.

4. Most game is harvested where access is easy — near a road, trail, river or lake. Where access is poor, decimating predators might backfire. High predator populations in remote areas might drive prey toward areas easily accessed by hunters.

5. Prey moving from place to place to avoid predators causes the prey animals to “graze” their home range more evenly, enhancing its productivity. Prey that stays in small areas may over-graze and suffer from more contagious disease.

6. Predators focus on easy – ill, injured or old – prey more often than on the prime adults, especially males, that most hunters prefer. Predation may partly counteract harvest impacts, keeping age-sex ratios closer to optimum than harvest alone does.

7. Snowshoe hare and rodents compete with moose for willow stems, a food especially crucial during winter. These competitors sometimes girdle so much willow that they limit the supply for moose. Wolf predation on hares and rodents could increase food supply for moose.

8. Willow are also a major source of protein for moose during spring when new calves are produced. Protein production requires nitrogen. At lower latitudes, plants get most of their nitrogen from air. This is far less effective in Alaska’s cold, wet soils. Willow can, however, get nitrogen from decaying salmon scraps and dung left by bears and wolves. Drastically reducing predator or salmon numbers could impair future moose productivity.

9. Optimum ratios of predators to prey will vary situationally. The Board of Game should tailor management tactics to local conditions rather than employing a one size fits all strategy across vast areas of the state.

10. Bear populations are far more vulnerable than wolf populations to over-harvest. Yet, The Alaska Department of Fish and Game is not closely monitoring bear numbers in predator-control zones, much less in noncontrol zones. True sustained yield predator management requires careful, detailed monitoring of all major factors affecting prey and predator populations before, during and after predator reduction periods. Only thus can the benefits of predator control be maximized while its impacts – e.g., on hunting and on hundreds of millions of dollars of ecotourism income — are minimized.

These are but a few of the issues that make predator-prey experts skeptical that “intensive management” really optimizes hunter harvest.

So long as the state fails to address these and other controversial points, its truths will remain half-truths where advocacy trumps objectivity, and propaganda masquerades as education. Worse, its battle against so-called “ballot box biology” will remain more fundamentally a battle against democracy — against having government policies guided by the public rather than by politicians and special interest groups.

Dr. Stephen Stringham earned his mater of science degree at the University of Alaska studying moose and his doctorate degree studying bears. He has researched predator-prey relations, including a focus on maximizing population viability in ungulates and bears by optimizing age-sex ratios. He is the author of five books on Alaska’s wildlife.

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