October 14, 2019

Can Moose Harvest Increase by Reducing Moose Density?

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mooseI admit that might be a misleading question but a question that should be considered in the grand scheme of things.

In the scientific community, moose management is described as multiple-criteria decision analysis or decision-making process. In layman’s terms it means that there are a whole lot of things that can and do effect the everyday lives of moose (wildlife) making the job of managing the moose population, at times, difficult. Perhaps the easiest part of managing moose is crafting a plan or a wish list of what each fish and game department thinks they would like to have for an ideal moose population. The real difficulty comes in pulling it off. Good luck!

If it was easy to have and maintain an ideal moose herd, then professionals would decide things like density (how many per square mile), how many males there should be, how many females there ought to be and how many calves survive their first year. In addition managers would strive to have the perfect age structure, i.e. not too old, not too young, etc. Again, good luck! This job becomes that much more difficult when “multiple-criteria” that drives the need to change plans and make decisions increases.

Ideally, in states like Maine, where the moose population has grown sufficiently that the state can offer an opportunity for a moose harvest by hunters, the herd is managed and manipulated in order to provide for a harvest while at the same time making adjustments to compensate for losses in order to grow, decrease or sustain a moose population.

George Smith, an outdoor writer and political activist, has begun a three-part series on Maine’s moose. Part I is currently available. He basically says that Maine biologists don’t know enough about the state’s moose population in order to make the right decisions. In a multiple-criteria decision-making process, it can only work effectively when scientists have a grip on the multiple criteria. While it’s important to know which decisions to make for each effecting criteria, no decisions can be made, at least properly, without recognizing and understanding the multiple criteria that effects the moose population.

I’m not sure that I could do a grocery list of multiple criteria justice but I’ll give it a stab. Here’s some of the criteria and realities that moose managers must deal with before making decisions on how to implement the right changes in order to make compensation:
1. Winter severity
2. Total mortality rates (and with this should be a good understanding of where all mortality comes from)
3. Virus and diseases
4. Predation
5. Habitat
6. Calf recruitment
7. Sex ratios
8. Age structure
9. Harvest data
10. And all the rest!

Maine is in the middle of a 5-year study on moose, in which it is hoped to gain a better understanding of moose populations and what is killing off the moose. Some think Maine’s moose herd is being decimated by winter ticks, combined with predation on calves by wolf/coyote hybrids in winter and bears in spring.

Historically, Maine has always had moose but it was not until after sufficient protections were place on them did they recover enough that in 1980 the state began it’s first regulated and limited moose hunt in many, many years. However, even at that time, managers didn’t know exactly how many moose Maine had…enough I guess.

Since that time and it seemed for many years, we were told Maine had 20,000 moose, or maybe at times 25,000 or 30,000 moose. Recently, Lee Kantar, Maine head moose biologist, made the assessment that the state had 75,000. But the number of hunting permits allocated hasn’t really changed a lot over the years falling somewhere between 2,000 and 3,000 permits. This has ruffled the feathers of some calling for dramatic increases in moose permits. Kantar proceeds with the utmost of caution.

It appears that Maine’s moose are being hampered by winter ticks. The second year of this moose study showed that ticks were responsible for killing a lot of calves throughout the winter – enough so that recruitment dropped to below 30%, an indication that a continuation of this recruitment percentage would begin to reduce the moose population and skew the age structure.

So, while some call for increases in moose permits because the official number remains at 75,000, is this the right thing to do?

Winter ticks are one of those “multiple criteria” things. Maine scientists must get a handle on this in order to deal with it in the right manner. We do know that ticks have always been around and reports state that the number of ticks goes up and down and it seems the majority of the discussion is focused on climate change as the culprit. I don’t completely buy into that excuse. Common sense should tell us that if moose population estimates were at all accurate, at least to a point that we agree that from 1980 until 2013 the moose herd has been growing, perhaps the real increase in winter ticks can be attributed to the increase in the moose population.

Maybe Maine is trying to grow moose in too large numbers.

In a moose study of Scandinavian moose, scientists looked at how to best compensate for losses of moose hunting opportunities, more accurately how to maintain hunters’ moose harvests, due to predators. In that study (there was no discussion about winter ticks) they presented two ways to compensate for losses in moose harvest due to predators. One was to manipulate the hunter harvest to keep moose densities high enough. The other was to change the sex structure of the herd to favor more female moose, thus producing more offspring, etc. This effort varied considerably due to changing “multiple criteria” involving the presence of predators.

Either way, the bottom line was that moose densities had to be high enough in order not to have to tell hunters they couldn’t eat moose meat.

Winter ticks are not predators in the classic sense but they might as well be a wolf, a pack of coyotes, or an ambushing bear. The result is much the same. We would have a difficult time to set traps and pay hunters and trappers to go kill ticks to compensate for moose losses, which in turn cut into hunting harvest opportunities. So what do we do about ticks?

There are two issues here as I see it. One is that I’m not sure that Maine biologists can sit by to see if their climate change is going to take care of the tick problem. If, as I suspect, the increase in winter ticks is directly related to, and maybe even an exponential factor, an increase in moose numbers, then maybe Maine needs to bring moose numbers back down. It seems to me that this is what is naturally occurring now with the increased winter kill. Perhaps if we kept numbers moderate enough in order to mitigate the tick problem, recruitment would remain strong and the result would be good or better hunting opportunities.

The second issue is about how many permits have been issued historically compared to what the moose population was. In truth, nobody knows what the moose population has been and as managers plodded along with the guesses, it appears that their issuing of permits had no negative effects on the moose population – the exception may be that because there was no money being spent to accurately count moose, the population got big enough that a tick problem broke out.

Consider the fact that wildlife biologists and environmentalists, when it’s convenient for them, like to tell us that a well-fed and healthy species population will produce more and better offspring. If there’s any truth to that claim at all, and to me it makes sense to a point, then for Maine to bring the tick problem under control, would, in the long run, at least maintain the current number of moose permits being issued and may even increase them – provided that the other “multiple criteria” don’t get out of whack.

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