Wolves And Idaho’s Fuzzy Math Challenge
May 6, 2008
Idaho is planning a wolf hunt in the fall of 2008. Whether that actually happens remains to be seen as no less than 12 environmental/animal rights groups have filed suit to reverse the decision earlier this year that took the gray wolf in Idaho, Montana and Wyoming off the endangered species list. Couple that with some of the same groups seeking a court injunction to stop all killing and hunting of the wolf immediately, it is probably doubtful there will be a fall hunt.
Regardless of what I think, there are some fuzzy math issues involving the Idaho Fish and Game Department that I can’t quite figure out. For those who don’t know, the IDFG is seeking public comment on rules and regulations concerning a proposed fall wolf hunt. Go to their website and you can register a comment. Preceding the comment box, this is the information IDFG has for you to read.
The Idaho Department of Fish and Game is seeking comments on proposed 2008 wolf hunting season and rules framework available here.
The Idaho Fish and Game Commission approved the Idaho Wolf Population Management Plan, and the gray wolf in the Northern Rocky Mountains was removed from the endangered species list – both in March. The management plan calls for managing wolves at a population level of between 500-700 wolves for the first five years following delisting. The plan includes hunting as part of the methods of maintaining the population levels.
Fish and Game recommendations call for a total mortality quota of 328 wolves in 2008, which includes all reported wolf kills – from natural causes, accidents, wolf predation control actions and hunter kills. Reaching the quota would result in an estimated end-of-year population of 550-600 wolves.
When the statewide quota is reached, all hunting would stop. When quotas in individual zones are reached, hunting in those zones would stop.
Details for the fall 2008 hunting season are scheduled to be set by the commission at the May 21-22 meeting and season and rules brochures should be out to the public in July.
IDFG says that the management plan approved by the U.S. Fish and Wildlife Service, is to manage a population of gray wolves of between 500 and 700. They propose a kill quota, this includes all forms of mortality on the wolf not just hunting, of 328 wolves, claiming this will result in an estimated population at the end of the year of between 550 and 600 wolves.
I’m no rocket scientist but I figured out from this mathematical equation, IDFG is estimating the population currently, or prior to the fall hunt, at between 878 and 928 wolves.
This seems to disagree with information that IDFG has made available. I did some of my own math using figures available from the IDFG website and other “official” documents. To be as up front and honest as possible, let me say that IDFG has for the most part made it known that their wolf population estimates are in fact just estimates but they feel comfortable enough to use them in official documents, etc. With that said, my calculations are then estimates being that I am using their data.
In 2005, IDFG estimated a wolf population of 512. Using that estimate, I went back to 1995 and 1996 and calculated out that to have that number of wolves after the reintroduction of wolves back in 95 and 96, worked out to a survival and growth rate of right around 33%, give or take a % fraction or two.
Using this same survival and growth rate, 33% and 512 wolves in 2005, that calculates out to an estimated wolf population of 1204.55 wolves by the end of 2008. Whatever anyone choses to factor into this equation – i.e. carrying capacities, current mortalities, etc. – that’s a substantially higher estimate of wolves than the 878-928 IDFG is saying the state currently has.
Once again using IDFG information, they say they want to have a kill number of 328 out of their estimation of between 878 and 928 wolves, leaving a total of 550 and 600 wolves. If we average numbers and say the current wolf population is 903 and the kill quota remains at 328, that’s a reduction of wolves of 36%, average.
If the real wolf population more closely resembles my calculations, 1204, then the reduction rate stands at 27%. Using a continued survival and growth rate of 33%, then the wolf population continues to grow at a rate of 6%. Using IDFG figures, they will for all intent and purposes maintain their wolf population or exact figures say an average reduction rate of 3%.
The fuzziness in the math comes from how and why IDFG opted for a current wolf population of between 878 and 928? Those numbers seem a bit arbitrary. Nearly every report that has come out of Idaho claims the current wolf population in the 1200-1500 range with some reports considerably higher than that.
Whether you’re an Idaho citizen for or against hunting wolves and delisting the animal, it would seem that for IDFG to win support from anyone, they need to do a little bit more to explain their fuzzy math.
Tom Remington
All I know is that while guiding and hunting for myself over the past few years, I have seen MANY wolves. It was kind of cool at first to see them and hear them at nights, but it became such a common occurance that I just wonder at the proposed population count. There are way too many of them in my humble opinion.