Alaska’s Wolf Control Programs 3: The Siren Song of “Managing for Abundance”
 
In Alaska, wolf and bear control are viewed as a way to alleviate competition between urban and rural moose and caribou hunters when there are shortages, real or imagined:  Kill wolves and bears to produce and maintain such high numbers of moose and caribou simultaneously across all the major hunting areas of the state that there will never be a need to apply the subsistence hunting priorities dictated by statute.
 
Advocates commonly refer to this thinking as “managing for abundance,” although the older name for it - “intensive management” - is still also used regularly.
 
As is often the case with alluring propositions, advocates of this one are ignoring the downsides.  It is the same “maximum sustained yield” (MSY) thinking that scientists have widely discredited for 30 years, since publication of a famous paper in 1977.  It is anything but good science and is unlikely to generate the advertised long term hunter benefits.  Nor is it mandated by the Alaska Constitution, as advocates often claim.  And these problems are only a prelude to others that are almost never considered, for example regarding the major biological, scientific, ethical, dollar, and other costs of killing wolves and bears.
 
Alaska Department of Fish and Game biologists talk about moose and caribou within fixed game management areas as if these were single populations or other meaningful ecological units.  They establish, often arbitrarily, objectives for the numbers and annual yields they would like to maintain within these areas, complete with “desired” sex, age, and predator-prey ratios.  Almost always this means attempting to keep numbers and yields at relatively high, constant levels within each area.  When the numbers and/or yields fall below the specified objectives or certain of the ratios deviate, the thinking turns largely to killing predators to bring them back up.  If the numbers and ratios increase well above the specified objectives, such as in Game Management Unit 20A (south of Fairbanks) at present, the emphasis shifts to heavier hunting to bring them back down.
 
The most recent example of a predator control plan based on this thinking involves a so-called emergency to try to halt a caribou decline on the Alaska Peninsula (March 9 blog entry).  
 
It is an old cornerstone of wildlife management - trying to “smooth out the peaks and troughs” of population change primarily to maintain high, ongoing yields for hunters.  Anything beyond what is needed to keep the population stable is a harvestable “surplus” for providing these yields.  
 
However, to a large and growing body of science - see, for example, www.resalliance.org - this represents just the opposite of true sustained yield thinking.  It is classic command-and-control resource management that in the long run seldom succeeds and in the process of trying does harm on many fronts, including sometimes to the very consumptive users, such as hunters, who are supposed to benefit the most.  
 
Things in the natural and man-made worlds don’t usually work at single scales.  They operate as systems at multiple interacting scales and across scales, such as what goes on annually between wolves, moose, and sheep within established wolf territories, between these units and other groups of wolves that migrate seasonally across territories, bears that prey seasonally on moose in some of the territories, and between all of the foregoing and the caribou subpopulations (“herds”) that migrate seasonally across the region for decades and then shift to other regions (e.g., see the Dec 2007 paper on the Reports2 page).  
 
And like all “dynamical” systems, these and other ecological systems behave with patterns of change over time that, underneath all the external influences (from drivers, stochastic effects, noise, etc.), amount to only a handful of potential major phases albeit with variations and special cases for each.  A key combination of “slow” variables - for example relating to predation, habitat quality, and ungulate harvest rates in a predator-prey system - “tuned” one way results in long periods during which system components (e.g., predator and prey populations) fluctuate mildly within one stable state or occasionally flip into a higher or lower state.  The tuning changes and the same system oscillates periodically.  It changes further and the system oscillates aperiodically.  It changes enough and the fluctuations are likely to become chaotic (“deterministic chaos” rather than complete disorder).  
 
The bottom line is that there is almost nothing here that resembles the steady-state population objectives that go hand-in-hand with the wishful thinking of command-and-control, aka MSY, management for abundance.  The highly unnatural attempts to dampen as much variability as possible (especially in downward directions) and hold ratios within narrow tolerances virtually guarantee that in the long run the managed systems and their component populations will be less able to absorb the natural and human-caused disruptions that are both inevitable and unpredictable in the real world.  This means a higher potential for sudden unnatural shifts to system states with even lower yields and unforeseen consequences for other valued natural features and ecosystem services.  
 
A more scientific view of sustainability would seek to retain as much of the natural, multi-scale spatial and temporal population variability and related behavior as possible because of its importance to system resiliency.  There would be more emphasis on adapting to rather than trying to control natural changes.  Moose and caribou harvesting strategies would feature much more spatial and temporal variation at broader scales, such as along the lines of the “rotating pulse harvest” approach described for caribou in Haber and Walters (1980).  In short, the proximate emphasis would switch from maximizing population yields to maximizing system capacities to absorb surprises.  
 
Alaska’s Constitution requires sustained yield resource management.  MSY/management for abundance is not the way to meet that requirement for either consumptive or non-consumptive objectives.  
 
 
Haber, G.C. and C.J. Walters. 1980.  Dynamics of the Alaska-Yukon caribou herds and management implications.  Pp. 645-663 in, Reimers, E., E.Gaare, and S.Skjenneberg (eds.), Proceedings of the Second International Reindeer/Caribou Symposium, Roros, Norway, 1979.  Direktoratet for vilt og ferskvannsfisk, Trondheim.  799 pp.  Also available from Arctic Environmental Information and Data Center, Univ. of Alaska, Anchorage.                  
 
 
Mar 15, 2008
Wolves are being killed in large numbers in Alaska under an interpretation of “sustained yield” that scientists have widely discredited for 30 years.