Can the WI DNR count deer?
 

From the WI Outdoor News. Sorry about the length

Officials question DNR deer estimate

By Dean Bortz
Editor
Madison — Conservation Congress chairman Steve Oestreicher is willing to accept the DNR’s revised 2002 deer population estimate of 1.3 million, but he also hopes legislators will allow the congress to spend $75,000 on an outside audit of the DNR’s sex-age-kill (SAK) deer population formula.

Oestreicher is less willing to accept the DNR’s recommendation for 49 Zone T units in 2003.

Last week, just days after the DNR announced its official population estimate of 1.3 million deer heading into September of 2002, Oestreicher said he wanted university scientists from Missouri, Colorado and Washington to conduct an audit on the DNR SAK formula. It’s estimated that will cost $75,000, and Oestreicher said he has already approached Rep. Russ Decker (D-Wausau) and Rep. Scott Gunderson (R-Wind Lake) for the funding.

“Right now I’m looking for money for this audit,” Oestreicher said. “There are people around the U.S. who have been studying SAK and could come in here to conduct an audit.”

Oestreicher said he isn’t asking the DNR to abandon the SAK formula in reaching deer population estimates, but he’s interested in having the state learn whether there is a way to “tighten up” those estimates.

He pointed to the discrepancy between last summer’s “herd projection” and the current “population estimate.” Last summer, DNR biologists projected that the state had 1.6 million deer heading into the various fall deer seasons. Those projections are made every spring, then are verified with the subsequent harvest registration. Based on the 2002 bow, gun, muzzleloader, tribal and CWD registrations, that original projection of 1.6 million was “ground-checked” now at about 1.3 million heading into the fall of 2002.

“I’d like to get this audit completed as quickly as possible,” Oestreicher said. “Somewhere in the neighborhood of half a million deer have been lost by the SAK between last spring and now.”

One-half million? That might be a little high, according to DNR wildlife officials.
DNR population ecologist Robert Rolley of Madison took a few minutes to review the process the DNR uses to reach various projections and estimates. Rolley explained that the DNR has to make projections each spring for fall deer populations. Those spring projections are then verified through hunter registration of deer. The same process is being used right now to prepare for the 2003 deer seasons. Biologists will make projections in April and May (they want to see how the winter finishes up) and will use those projections to finalize antlerless quotas.
“The 1.6 million we thought we had last fall was a projection we had (based on) last winter’s post-hunt estimate,” Rolley said. “Every year we get a new harvest and then use that as the basis to estimate the population that produced that harvest. From the 2002 harvest, we’ll calculate the actual estimate of the pre-hunt population. From year to year, the population estimate could be different than the projection heading in. A population ‘projection’ is used to plan the harvest, then that projection is ground-proofed by the harvest and deer registration.
“Based on that process, we’re now saying we went into fall with about 1.3 million and came out with about 915,000 deer,” he said. “We’ll make forecasts later in the winter about what we might expect in the fall of 2003. By mid-March we finalize quota plans.”

So, is the difference between the 2002 projection of 1.6 million deer and the current estimate of 1.3 million (pre-hunt, 2002) a big deal?

“Some people might want to make it a big deal,” Rolley said. “There definitely were lots of things happening with this past season that caused us to have a little less confidence in estimates than a normal season.”

Some conservation groups that follow the annual herd population estimates say the numerous Zone T seasons and resulting high antlerless kills have made the SAK process less accurate, because it relies heavily on the buck kill.

“That’s not a good generalization,” Rolley responds. “Some of the areas where we had the most agreements between SAK and other modeling was in the eastern farmland region where we’ve had Zone Ts for several years now.”

Rolley said DNR biologists and wildlife managers had a number of questions on how to interpret the harvest across the whole Northern Forest Region.
“We saw a fairly substantial drop in buck kill in 2002 over what we’d seen in 2001, both in archery and gun seasons. We tried to interpret how much of that was due to reduced deer numbers, or for other reasons, most of which surrounded the CWD issue.”

Right now, the DNR has the statewide over-winter deer population at 915,000. The statewide over-winter goal is around 710,000 (now that goals were lowered in CWD zones).

“We are looking at 45 to 50 Zone T units. That will be firmed up and presented to the Natural Resources Board on Feb. 26. There will be no earn-a-buck in 2003 Zone T units, outside the CWD zones, but it could kick in in 2004,” Rolley said.
Conditions this winter are shaping up for another spring of good fawn production.
“All indications are we should have good fawn production. We could easily be back to 1.3 million by fall, but that’s not a prediction,” Rolley said.

In the meantime, Oestreicher will begin contacting three outside researchers on the possibility of conducting an SAK audit.

“The congress is still working with the DNR, but if there is a way to improve our SAK formula, or the process we use in reaching deer population estimates, why not do it?” he said. “The DNR is being aggressive with antlerless quotas despite the fact that the SAK came in lower than anticipated. I know they’re being aggressive in the event there are more deer out there than the SAK is showing.”

RE: Can the WI DNR count deer?
 

I especially love this quote, from one of the professional biologists:
Yeah, what the heck! Being off by a factor of around 20% ain' t no big deal![:@]

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RE: Can the WI DNR count deer?
 

Don' t get me wrong: I' m not looking for perfection by any means. But SAK has had such glaring statistical problems with it an audit of the result is way overdue.

Basically, here' s how it now works. SAK uses the previous year' s buck kill as one of the main variables to calculate the deer population. It doesn' t take into account the effect of T-zones and other antlerless kills. No wonder it appears that the population estimates are off by as much as 20%! So here we are, having all sorts of t-zones supposedly because so many units are " overpopulated" .

This has little to do with deer biology and more to do with statistical sampling. This method is flawed, plain and simple.

We were better off in the old days counting deer turds.

RE: Can the WI DNR count deer?
 

The sak seemed to have worked quite well when we had Edsels AND killed 2 bucks-1 doe. Now, it' s the other way around (according to their numbers). BUT, we don' t really know because we have no true number of buck or doe kill. We offered to fund this counting, since they said they were short of money, but they refused.

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RE: Can the WI DNR count deer?
 

Brian,

Great perspective! I had not thought of it in those terms, but I believe you' re on to something.

As an adjunct to your point, I remember seeing in the Deer 2000 stats...cannot recall exactly where...all of the areas where overwinter goals were lowered at some point in the 1990' s. Suddenly, areas that had not been considered as problems were now considered to be " overpopulated" , simply because the goals had been lowered.

I still have a problem with the way that SAK works. Having a decent statistical background, having buck kill as the main variable used to try and calculate population is going to be subject to a large standard deviation. An error of 20%...or more...would not be surprising. I don' t know what does work better, but the idea of an outside audit of the results can' t hurt.

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RE: Can the WI DNR count deer?
 

Brian, I agree. I think WDHC' s point concurs with that as well. SAK would be fine under the " old" structure we had 10+ years ago. That is, no t-zone, etc. That is not the situation now. And as you put it, adding forumlas to formulas is tricky business. This in large part explains the 20% disparity in deer count that appears to be the case this year. With that margin of error, SAK becomes worthless.

Again, I think the overwintering goals are part of the problem in many areas. And " hunter satisfaction" is one issue that the DNR cannot simply ignore when coming up with population goals. As they have stated many times, hunters are their primary " deer management tool" . It' s not smart to create animosity with your most important " tool" , especially given the fact that you might need them down the road for, let' s say, an " eradication zone" . On a previous thread, I raised the issue that the DNR is their own worst enemy when it comes to PR. Not that it is possible or even desireable to try and structure things so that everyone is happy. But when we see polls like the one that came out of the Deer 2000 survey that indicated only 18% of hunters had a high degree of confidence in the DNR, that indicates a problem.

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RE: Can the WI DNR count deer?
 

Great points, Brian. And I agree wholeheartedly with your analysis. I face a similar problem where I hunt...not too far from you in fact. I hunt in Trempealeau County near Arcadia. We have almost exactly the same issue.

Back in the early 1990' s, the area DID have a problem with overpopulation. No question. It was very common to drive around in the Spring and Summer evenings and see one hundred deer or more in a twenty minute time frame. Ag tags and t-zones were needed, and, along with those of us practicing QDM and harvesting does, the problem was taken care of. Now we have an identical situation to what you described. Just identical to what we have. But also in our area, the DNR is trying to solve a " problem" that doesn' t exist. We have asked the same questions at meetings and, unfortunately, got the same answers you got. Two years ago, we did manage to pin one of the DNR people down on the WHY of lower overwinter targets. One of the more feeble answers we received was that, if they allowed for a higher goal, then the " possibility of greater crop damage would exist" . Hmmm...the " possibility" ?! By that standard, we should shoot all the deer so there is no " possibility" .

This is one reason that I criticize the DNR. They don' t listen to us, they hold the meetings for show more than substance, and they seemingly ignore us with regards to issues like this. Want to control crop damage? Fine. Avoid car collisions? Fine. But to what degree? To the degree that hunting opportunities are dimished and land values fall? We' re not there yet, but it wouldn' t take much for that to occur. Sure, some parcels that are unhuntable or very difficult to hunt (some of the marshes around Dodge, Meinert' s Slew on the Trempealeau River, etc.) may have higher than desireable populations. But most other areas are below that by a long shot.

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RE: Can the WI DNR count deer?
 

I agree, Brian.

And with that being the case, that is why I get irritated at the DNR and their contention that the units are still over goal and we still need a t-zone, or earn-a-buck, or whatever. It is baffling to me that the goals are largely achieved, but that is still not good enough. Again, it simply leads to a lot of resentment from landowners and hunters when the DNR tries to solve a problem that isn' t there.

We had the same problem with the herd being out of whack. Now that the ratio is more in line with a sustainable level...with regard to reproductive potential and available resources...we have seen a great increase in results. I won' t say that trophybook bucks are " common" , but we tend to see at least one taken every year. In the past, it was one every 3 or 4 years. Of course, passing up the little ones had an impact, but we did not notice any real benefit until we started shooting out more does.

RE: Can the WI DNR count deer?
 

The overwinter goals are to be reviewed every 3 years for each unit(by rule), BUT if you aren' t there at your unit meeting(where you hunt) and bring it up(or someone) and vote to raise it, do you think they are going to mention it ?
In 1 area I hunt, it was 20 and we voted(the people in attendance) to raise it to 30. The dnr rep said we could only raise it to 25. No more than 5 at once. Now, nowhere have I found this in stone or law.

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RE: Can the WI DNR count deer?
 

Brian, was this during the hearing last year? I couldn' t make the one last year; I do recall hearing something about a vote that had some " Florida-like" counting going on. Maybe that was the one.

Funny, I was recently going thru some old papers and found one for the 1993 deer hunt. It talked about the limited number of doe tags available for unit 61 due to " the population being significantly under goal" . This was a year when I saw well over 100 deer while hunting opening day!

Brian, sounds like we need to mobilize a bunch of folks to show up at the next meetings in unit 61.

RE: Can the WI DNR count deer?
 

NO!!! Any other questions?

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RE: Can the WI DNR count deer?
 

Brian, this reminded me of an exchange I had with one of the DNR officials at one of the meetings a few years back. I was questioning the " boom-bust" deer management that we seemed to be witnessing. " Why no doe tags this year and then a whole bunch of crop damage permits the next?" I asked if anterless harvest was the goal, why not give out one free tag with a regular license? I was told " Too much lost revenue" . Two years later, unit 61 was a t-zone, and hunters could get free tags at a rate of two per hunter per day during all of gun and bow season!! Talk about a change of heart! Also talk about some questionable wildlife management...but that is for a different thread.

So we go from " Not enough deer" to " Shoot everything you see" . I understand the changes in population, but that much? And why suddenly is 15 deer the " magic number" when 20 or 25 was fine a few years back? There is less crop damage, car accidents are about the same in the unit, and there are definitely fewer deer in the area.

Back to the issue of whether the DNR can effectively count deer. My feeling is that the DNR is keeping goals like this around because they are coming up with estimates of total population that are higher than what is actually out there. So in our case, unit 61, the DNR sets a target of 15 deer because the beloved SAK says we are still at 20 or 19 or whatever. Set the goal low so that you can justify a higher kill requirement; hence t-zone or earn-a-buck. In reality, simply based on the statistical deficiencies of the SAK system, I' ll bet we are at, near, or below the 15 deer per sq. mile allotment that the DNR is aiming for. THAT, I believe, is the root of the problem.

RE: Can the WI DNR count deer?
 

Brian & TJD, You both make some great points. I do believe if we broke down the antlerless kill by sex, we would have a better handle on the size and structure of our herd.

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RE: Can the WI DNR count deer?
 

For anyone outside unit 61, below is the link to the DNR' s map of deer per sq. mile vs the overwinter goal:

http://www.dnr.state.wi.us/org/land/...DEER/SAK02.pdf



The problem I have with SAK is illustrated pretty well in your overview of the stats for unit 61. There is no way there are as many deer per sq.mile now (24) as there were in 1994. Not a chance! Especially given the number of deer taken in the various t-zone hunts, ag tags, etc.
I tried to find the per unit total harvest going back to 1992, but was unable to locate on the vast DNR website. The total statewide numbers for gun season from 1992 until now are as follows(rounded to the nearest thousand) : 289k, 217k, 308k, 398k, 388k, 292k, 332k, 402k, 528k, 361k. I' ll bet for the most part unit 61 saw similar trends.

Here' s what is interesting. Note that comparing the harvest in 1992 to 2000 there was a net increase of roughly 240,000 deer, or an increase of about 80%. That is again, the total harvest. During 1992, of that total 111,000 were bucks. During 2001, bucks accounted for 171k of the total harvest; an increase of about 60%. During the same period, however, the antlerless harvest differential is staggering: 177k in 1992 up to 357k in 2000, an increase of 180,000 deer, or an increase of just over 100%! Given the number of t-zones, etc. not an unsuprising statistic.

But now back to SAK. The main variable in trying to calculate deer population is the prior years' buck kill. The buck kill here rose as at a percentage by 60%. Yet antlerless kill more than doubles during the same period. Unless mature whitetail bucks are now capable of giving birth, how does the population of deer stay the same with a doubling of the antlerless harvest? Now this year, the buck harvest falls to 114k, and what is SAK saying? There are fewer deer! Again, the flaw of the system is that it assumes hunter behavior. Lower buck harvest, before a subjective adjustment is thrown in, indicates fewer deer. Larger buck harvest- more deer. Based on the formula, the DNR cannot declare success in any unit until most hunters are so PO' ed about not seeing deer that they give up. Apparently then the DNR can say they have hit their magical overwinter target in each unit.

What a system!

RE: Can the WI DNR count deer?
 

Did anyone read the WON article where they were talking about the population and the 15 factors involved with figuring the Buck Recovery Rate ? The one main factor, not even mentioned, is the buck fawn harvest. We all know it' s gone way up with tzone and EAB. The other pile came from Hauge- Now, we KNOW that bucks die twice as fast as does. We' ve heard this from Mytton and others. It' s a crock. They should look at their own numbers over the last 10 years. We' ve been killing closer to 1:1 than 2:1. When the SAK came about, we were killing about 4 bucks per doe, and registering each deer for what it was. It' s time for an oil change, and a new filter.

RE: Can the WI DNR count deer?
 

Kind of going along with WDHC' s point, I thought continuing this on a new thread might make it easier to read/edit, etc. See " Can the WI DNR count deer?, Pt II"