|1. How many moose and caribou each area of Alaska can support indefinitely?
1a. What are the peak known densities of moose and caribou each area?
1b. How much food did it take to support each peak population?
1c. How much does food supply vary from year-to-year or decade-to-decade? For example, the Kenai Peninsula’s carrying capacity
for moose was far higher decades ago (when I studied them) than it is now. For fires in earlier years had cleared huge areas of forest,
allowing proliferation of moose foods. Since then, regrowth of forest has vastly reduced those foods.
1d. How many moose and caribou could each habitat support currently?
1e. How far below peak density is a hoofstock population most productive? According to classic theory, animals are healthiest and
sustainable yield is maximized when density is at half the peak level. For some species, however, productivity is maximized much
nearer peak carrying capacity. Where are the peaks for moose or caribou?
2. Estimate optimum densities of wolves and bears at each stage of the hoofstock recovery effort – i.e. during both the
predator reduction and predatory recovery periods. Take into account effects of changing predator densities on
2a. hoofstock recovery
2b. predator population viability and growth/shrinkage rate.
2c. ecosystem viability
2e. other public benefits from wolves and bears
3. Rate the suitability of each area of the state for meeting consumptive, non-consumptive, and ecosystem needs. The
current system of “game management subunits” may be an appropriate basis for planning management of hunter harvest; but different
(overlapping) systems of land subdivision is needed for management for wildlife viewing and perhaps even for ecosystem health.
Once an appropriate system of land areas is mapped out, assign use priorities for each area. Instead of giving consumptive uses first
priority across most of the state before other uses are considered, each user group might be allowed to assign priorities to just one
area at a time, whereafter the next group could set priorities for another area, and so on “round robin.” Ideally, any area prime for a
given use might be given priority for that use. However, where any area is seen as prime for two or more uses, compromises should
serve the greatest number of people as fairly as possible.
4. Experimentally reduce wolf and/or bear densities in a few selected areas.
4a. Ideally, there should be two more ecologically-similar predator-reduction areas. Each area selected for predator reduction should
be paired with an ecologically similar area where predator numbers will be left alone.
4b. Predator reduction should be carefully monitored so that the rate and amount of reduction are known, and to contain reduction
actions within specified geographic boundaries.
4c. Monitor immigration and emigration of predators and hoofstock.
4d. Monitor status of hoofstock populations.
3e. Monitor abundances of food for both predators and prey. Predator foods include not only moose and caribou, but alternative
prey (e.g., snowshoe hare, salmon) and plant foods (e.g., berries).
4f. Monitor health of predator and prey populations (parasites, diseases, injuries, age-sex ratios, body fat indices, etc.)
4g. Monitor competition by other herbivores (e.g., snowshoe hare and rodents) for plants eaten by hoofstock or by predators. To
what extent does such competition limit food supply for moose or caribou?
4h. Monitor weather and any other influence that could alter predation rates or bias estimation of predation rates.
5. Once moose and/or caribou approach target densities, allow predator numbers to increase, while continuing to
monitor all of the above factors. Continue post-predator-control monitoring to assess long-term consequences.
5a. Are elevated densities of the hoofstock sustainable? How much does spread of disease or parasites increase? Does the habitat
become over-grazed? Do the hoofstock become socially stressed? Does vulnerability to predators increase?
5b. As predator numbers increase towards target levels, do hoofstock populations continue to grow, stabilize, or shrink?
5c. Set harvest regs for hoofstock that do not exceed sustainable yield despite increased predation.
5d. If and when harvest demands increase, estimate how much predator numbers would have to be reduced to prevent hoofstock
populations from declining. Again balance any benefits from reducing predator density with impacts on non-consumptive uses, on
ecosystem viability, etc.
6. Evaluate results. Revise management plans to adapt to updated understanding of predator and prey ecologies.
Repeat the experiment in new areas if needed.
|A PREDATOR-PREY MANAGEMENT STRATEGY
THAT DOESN’T VERMINIZE WOLVES & BEARS
Stephen F. Stringham, PhD
When I lived in the deep bush, killing a moose was like winning a lottery. It didn’t put a fortune in my pocket.
But it did put food on the table through a long cold winter when we would have otherwise starved.
|furbearers may be the only feasible option.
Nevertheless, I don’t rationalize that harvest is the highest and best use of all wildlife for all Alaskans. Tourism is our second biggest
industry, and wildlife viewing is one cornerstone. Ecxotourism brings Alaska $1 billion/yr. That translates into a lot of jobs, incomes and
tax dollars. Yet, management of wildlife for viewing is still primitive, and it’s given far lower priority than consumptive uses by both
ADF&G and the Board of Game. Lower yet is management to sustain ecosystem viability and thus the sustainability of all our wildlife
|Winning the Wilderness Lottery - Survival!
|To begin, let’s assume that the State is correct in believing that:
1. Predator numbers need to be drastically reduced in some areas so that moose and/or caribou (hoofstock) numbers can grow back
to optimum densities.
2. Once the hoofstock to wolf or bear ratios are high enough, a hoofstock population could not merely hold its own, but keep growing
to carrying capacity of its habitat.
3. Once hoofstock density (i.e., moose and caribou per 100 sq miles) exceed certain thresholds, wolf and bear numbers could grow
again without jeopardizing the hoofstock or depriving people of hunting opportunities. One reason is that even when prey are super
abundant, competition among wolves tends to limit their own density, usually below 20 wolves per 1000 square kilometers.
|Has the State set any targets for recovered wolf and bear populations? Are those recovery target densities, to say nothing of interim
predator densities, high enough – and are the predators trusting enough -- to fulfill non-consumptive user needs? What about
Isn’t the State’s real approach to predator reduction just eliminating as many wolves and black bears as possible as fast as it can?
What criteria would trigger slowing or stopping predator reduction before predator population viability is jeopardized?
If predators can stay in balance with prey, then why did the hoofstock populations ever fall so low that predator control was deemed
necessary? Why has predator control been a priority since long before Statehood? Were these populations over-harvested by
people – beginning when the human population density was far below current levels?
If prey populations began declining soon after past aerial predator control programs ended, what reason is there to believe that
predator populations could increase after the end of current control programs without the same result? Wouldn’t massive reduction in
predator numbers become permanent, especially in areas where human hunting pressure is highest?
|The State might claim it is doing all that, or at least plans to do it. But is that true?
|How do we get started? By assessing where we are and what has already been accomplished. We review key recommendations
by the National Academy of Sciences in its 1997 report Wolves, Bears & Their Prey in Alaska? What scientific questions still
need to be answered to make this work? [Once goals have been specified, appropriate means can be selection and inappropriate
|Obviously, that needs to change. But how – for instance in terms of predator control?