Friday, April 18, 2014

Managing Wolves by the Numbers


Under the endangered species regulations governing gray wolf recovery, states must monitor wolf numbers and file annual status reports on wolf populations and packs on an annual basis. Federal authorities review the reports to ensure wolves are being properly managed above minimum standards to avoid relisting wolves as an endangered species. Evidence across the country, and now from neighboring British Columbia, suggest that the current process of counting wolves (which guides wolf management) may not be accurate.

Due to claims that monitoring wolves via radio collars, aerial observations and trapping can be an expensive task, many states have implemented a "patch occupancy model" for counting wolves. The occupancy model depends exclusively on hunter surveys to determine wolf populations and wolf locations.  This information, combined with prey base estimates and landscape data, become the formula for predicting  the  probability of wolves in a given area. This newer method might be less expensive, however, it is our understanding that it has not undergone rigorous scientific peer review for wolves, and is at best a guesstimate based exclusively on hunter experience in the field. 

n Montana, the patch occupancy model estimates the wolf population 25-35 percent higher than the verified minimum counts led by state agencies.  For instance, population modeling for Montana's wolves in 2012—where actual counts verified a minimum of 625 wolves and 147 packs—predicted that 804 wolves and 165 packs inhabited the state.

It is neither scientifically sound nor ethical to base critical decisions about public "harvest" on statistical predictions and not hard data.


Should we be managing wolves by the numbers at all?

By Wolf Conservation Center's Diane Bentivegna

As we learned from Dr. Gordon Haber's 43 years of wolf research in the book "Among Wolves," written with Marybeth Holleman, when it comes to wolves, it's not about numbers. It's about its pack. A wolf is a wolf when it's part of an intact, unexploited group capable of complex cooperative behaviors and unique traditions. If a pack is left unexploited, it will develop its own traditions for hunting, pup-rearing, and social behaviors that are finely tuned to its precise environment.

Wolves should not be managed by the simplistic models most commonly used by today's hunter-dominated wildlife agencies. The notion that we can "harvest" a fixed percentage of an existing wolf population that corresponds to natural mortality rates and still maintain a viable population misses the point. You can't manage wolves by the numbers.

You can't just count the numbers of wolves over a particular area and decide whether it's a "healthy" population. That's because the functional unit of wolves is the pack. If we leave wolves alone, they will manage their own numbers in concert with their environment. And, if we leave wolves alone, we will be the ones to benefit - for the presence of wolves brings natural balance to ecosystems.

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