deerfly 
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Deer Population Estimates
The PGC has released their population estimates for each WMU as directed in the Audit. Here is the link to the report. Go to the section on research and click on ,"Monitoring Deer Populations in PA" http://www.portal.state.pa.us/portal/server.pt/community/deer/11949 They did their very best to make it as difficult as possible for the average hunter to understand or question the results.
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Twowithone
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RE: Deer Population Estimates
2011/02/03 08:47:12
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You aint kiddin there deerfly. Think thats the way the commish likes it .
09-11-01 SOME GAVE SOMETHING. 343 GAVE ALL F.D.N.Y.
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dpms
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RE: Deer Population Estimates
2011/02/03 08:49:54
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ORIGINAL: deerfly
They did their very best to make it as difficult as possible for the average hunter to understand or question the results.
With time, I am sure you will figure out why they are inaccurate and how the hunters of Pa. are being mislead. 
My rifle is a black rifle
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Ironhed
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RE: Deer Population Estimates
2011/02/03 10:28:44
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dpms, "That is simply not true!"  Ironhed
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S-10
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RE: Deer Population Estimates
2011/02/03 11:50:03
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Actually, the math used is fairly basic and once you put the numbers in place of the letters is not all that confusing. Where you can see the limitations on the accuracy is by reading the assumptions they have to make. The PGC even acknowledges the limitations of the model.
In reading how the model was put together two issues immediately come to mind that show potential problems with how it is used.
1. The PASAK assumes the antlered harvest rates are related to hunter effort. In any sport, the least successful participants are the ones that drop out first. Often times the least successful participants are the ones that put in the least effort as has been discussed here. RSB refers to them as road hunters,and worse. The 200,000 who have recently dropped out contain a large mumber of those who put in the least effort. That fact would skew the PASAK assumption.
2. The charts derived from the PASAK show the herd to be stable in the WMU's from 2004-2009. Per the PGC, the antlered harvest is a good population barometer. The actual antlered harvest shows a decreasing population from 2004-2009.
Unless the harvest increases in 2010 as expected, after poor weather being blamed for 2009's low harvest, the assumptions in the PASAK will be questionable at best.
This is the third different population model that has been used since the start of AR/HR. In 2001 they Knew we had 1,600,000 deer based on that science we are supposed to believe in. Now we admit we are only guessing on deer numbers. Amazing
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wayne c
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RE: Deer Population Estimates
2011/02/03 12:54:39
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With time, I am sure you will figure out why they are inaccurate and how the hunters of Pa. are being mislead. Not possible. Pgc would never lie. Pgc is looking out for us and our best interest...whatever do you mean? lmao!  And yes, that was sarcasm.
post edited by wayne c - 2011/02/03 17:24:48
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World Famous
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RE: Deer Population Estimates
2011/02/03 13:25:40
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I believe someone posted a ,while back ,of a 47% reduction in the herd since 2000, and "someone" said "not so". The numbers of deer in 2000 to the reduced amount by this estimate would be dang close to 47%....WF
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deerfly
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RE: Deer Population Estimates
2011/02/03 17:02:22
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Here is one reason that the results from this report will do little if anything to improve the credibility of the PGC. They are not claiming the populations in each WMU are stable for the period cited, they are claiming, the coefficient of variation is stable For example , the pre-hunt estimate for 2A decreased from 100K in 2003 to 73K in 2009 the CV remained stable at 17%.
Here is another reason why some will question the report.
"23. Do PASAK estimates represent only hunted populations?
No. Unlike previous methods used by the PGC to estimate deer populations, the PASAK model includes
data from deer on both hunted and unhunted land. Antlered harvest estimates are based on marked deer
that are captured and then released. On average, the young bucks will travel 3 to 6 miles from where
they were captured. Some will relocate to lands open to hunting; others to lands where no hunting
occurs. The same is true for adult bucks. As a result, the antlered harvest rates represent a combination
of animals from hunted and unhunted properties. "
The are assuming the buck harvest rate is the same across all WMUs , except for 2B, 5C and 5D and it appears that they are assuming the buck harvest rate remains constant over time despite the effects of the weather or other variable,
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wayne c
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RE: Deer Population Estimates
2011/02/03 17:19:41
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I believe someone posted a ,while back ,of a 47% reduction in the herd since 2000, and "someone" said "not so". If youre gonna make statements like that, at least confirm who your talking about. It says in reply to me, and I didnt make either one of those statements!
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World Famous
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RE: Deer Population Estimates
2011/02/03 17:27:44
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Wayne, wasn't to you. I am NOT computer savey. Somewhere in the posts I remember seeing that. Maybe it was a senior moment on my part...WF
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wayne c
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RE: Deer Population Estimates
2011/02/03 17:29:52
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No problem, i didnt think ya did mean me, but just wanted to be sure others understood that too.
post edited by wayne c - 2011/02/03 17:30:40
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deerfly
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RE: Deer Population Estimates
2011/02/03 17:54:53
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Here is a question for S-10 and Dardys, who math skills are probably a lot better than mine. Is the PGC saying that the harvests are keeping the herd stable or are they saying that the harvests are keeping the population trend stable? In other words if the harvests were reducing the herd in 2003 and the subsequent harvests continued to reduce the herd, the trend would be stable but the population would be decreasing.
The population estimates for many WMUs show the pre-hunt estimate decreasing while the coefficient of variation (CVs) are stable. I know that the CVs is the standard deviation divided by the mean, but can you tell me how that applies to this situation?
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Dr. Trout
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deerfly
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RE: Deer Population Estimates
2011/02/03 18:41:35
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You're to late . gino used data from the old AWR which were calculated using an entirely different method so the comparison is invalid.
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S-10
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RE: Deer Population Estimates
2011/02/03 19:01:17
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Is the PGC saying that the harvests are keeping the herd stable or are they saying that the harvests are keeping the population trend stable? I When I read it the first time I felt they were saying both the herd and trend were stable. When you look at the wide variation in 2G in the CV and compare it to 1B CV variation it seems that they can't both be stable. 1B actually shows an increase in deer numbers. There is such a wide variation between the high and low estimated population that it is little more than an educated guess.
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Dr. Trout
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RE: Deer Population Estimates
2011/02/03 19:06:51
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BT... HUH ???? to late ???
I'm using the figures RSB posted on my board .. which shows 8,000 less deer in 2003 for 2A pre-season, but maybe that is not a significant difference????
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deerfly
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RE: Deer Population Estimates
2011/02/03 19:19:47
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RSB was using the data based on the old method for estimating populations. The new estimates are based the harvest rates from the collared buck study. That easily accounts for the difference.
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CallJonyCochran
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RE: Deer Population Estimates
2011/02/04 01:01:04
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The populations were determined to be stable using a mann-kendall test.
It's interesting how people can form such strong opinions when they are so uninformed; when they know they are uninformed and they continue to defend their stance. What's more interesting is that most people on here are more informed on this issue than 99.9% of the American public on issues on which they feel strongly (e.g., healthcare, economy etc) myself included. Fisherie is a microcosm of society.
IMHO If I couldn't figure out how a mark-recapture estimate works and how population levels are estimated based on this document, I wouldn't be spreading my opinion on the matter of deer management. But to each his own, it is after all an internet message board and it is entertaining to read. The population estimates are pretty well laid out...however, you just can't dumb down a mann-kendall test.
disclaimer: I don't care about deer management in PA, and this is the first document I've read on the matter.
Good Day
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wayne c
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RE: Deer Population Estimates
2011/02/04 01:59:49
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Populations given in numbers that are lower pretty much every year over a period of several years, resulting in significantly lower.. are not stable populations. Populations when viewed as a line graph...where the graph goes straight down basically steadily over a period of several years... Is NOT a stable population! lmao. Course we can set our own parameters and say; if the population declines but declines less than "x" every year, we'll still categorize it as "stable". Then when it happens year after year and we end up significantly lower cumulatively...Its still "stable" lol. Pgcs methods are a joke.
post edited by wayne c - 2011/02/04 02:00:28
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deerfly
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RE: Deer Population Estimates
2011/02/04 07:59:21
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ORIGINAL: CallJonyCochran
The populations were determined to be stable using a mann-kendall test.
It's interesting how people can form such strong opinions when they are so uninformed; when they know they are uninformed and they continue to defend their stance. What's more interesting is that most people on here are more informed on this issue than 99.9% of the American public on issues on which they feel strongly (e.g., healthcare, economy etc) myself included. Fisherie is a microcosm of society. Â
IMHO If I couldn't figure out how a mark-recapture estimate works and how population levels are estimated based on this document, I wouldn't be spreading my opinion on the matter of deer management. But to each his own, it is after all an internet message board and it is entertaining to read. The population estimates are pretty well laid out...however, you just can't dumb down a mann-kendall test.
disclaimer:Â I don't care about deer management in PA, and this is the first document I've read on the matter.
Good Day
If you are familiar with the Mann-Kendall test, would you please explain what it means when a population trend is determined to be stable even though the pre-season estimates are decreasing. Apparently they are basing their determination regarding the stability of the herd on the coefficient of variation, but they didn't explain what the coefficient of variation means and how it is determined. Thanks
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deerfly
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RE: Deer Population Estimates
2011/02/04 16:25:50
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Has anyone figured out what the PGC means when they say the population trend is stable? Are they saying the herd is decreasing at a constant rate or are they saying the population stayed the same from 2004 to 2009?
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CallJonyCochran
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RE: Deer Population Estimates
2011/02/04 16:37:24
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Deerfly,
I'm not sure on the specifics of the mann-kendall test as I'm not an expert on non-parametric statistics. But with all statistical tests, for there to be a significant difference, the point estimates along with the variability are considered, and if the variability of two point estimates overlap, then there is not a significant difference. You can't say that the population is increasing or decreasing if the variability associated with each point estimates overlap. I haven't really looked at the numbers specifically, but if the populations are considered stable, then the 90% Confidence Intervals probably overlap (Again I don't know the specifics of the m-k test, but this is probably a good approximation). The CV has nothing to do with the trend, it refers to the precision of the estimate for a given year. They didn't explain how they calculated CV because the average person reading this wouldn't understand it, but I agree in peer-reviewed literature they will explain the how they calculated the CV.
Wayne C,
People constantly ask for science based management...well here it is right in front of your eyes. The PGC methods are not a joke this is the way science and statistics work, if you don't like the results then you don't like science based management period. No credible scientist or statistician would say that the population is declining given the estimates and variability. If you really want to be informed, I would suggest less Fox News and more reading.
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deerfly
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RE: Deer Population Estimates
2011/02/04 16:51:16
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But with all statistical tests, for there to be a significant difference, the point estimates along with the variability are considered, and if the variability of two point estimates overlap, then there is not a significant difference What do you mean by this,"if the variability of two point estimates overlap" ? It would help if you used an example from the report. Thanks
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wayne c
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RE: Deer Population Estimates
2011/02/04 17:00:00
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People constantly ask for science based management...well here it is right in front of your eyes. Hmm. Thats funny i dont see it. Neither does any of the other wildlife management agencies that are not reducing their deer herds in the name of more trillium and hobblebush. And at least one biologist/forester/ecologist has spoken out and agrees the "science" is not what is driving our deer management program. And im not speaking of any one particular practice but of the program as a whole. The PGC methods are not a joke Well i guess you, me and several hundred thousand hunters will just have to differ on that'n. this is the way science and statistics work, if you don't like the results then you don't like science based management period. Uh, no, you dont set the parameters of what is and what isnt scientific management. I do support science based management, and i dont see one state in the nation that doesnt utilize science. There can be much variation in science based management. Some scenarios much more acceptable to and taking more into account, the hunters satisfaction/views. Scientific management strategies do vary in their methods and goals. In our instance, the application of the science is very open to debate And the labeling of "science based or not science based" does not hinge upon pgc doing things exactly as they have. In fact, the science could rightfully be called "flawed" due to their ignoring the very management tool itself in decision making...If "hunters" are to control the herd, there satisfaction is important to keep that tool not only intact but "efficient". That doesnt mean ignoring their desires leading to many hunters limiting their time afield, limiting recruitment and having retention issues. "No credible scientist or statistician would say that the population is declining given the estimates and variability. When the numbers indicate it, Decline is decline. Calling it something else doesnt change that fact. Would you support a 5000 per year pay cut every year for the next 10, if your employer told you it was acceptable variation for 5k up or down....but unluckily it has been down each year..., and at the end, employer told you that your pay was "stable" and didnt decline, even though youd just lost out 50 grand? lmao. Remember, with the deer herd, we are talking about an asset here.. We arent just discussing numbers that dont mean or represent anything....a valuable asset in the eyes of the "hunter" stakeholder group as well as others. A decrease to that asset should be no less acceptable, especially when its completely preventable.
When the direction of variation is more or less singular in direction and cumulatively significantly effecting the direction over time... It should no longer be considered acceptable variation and should be made an effort to counter the trend, if that trend is not towards the supposed goal end result (in this case stabilization) and its not! If you really want to be informed, I would suggest less Fox News and more reading." I have no doubt that ive read a helluva lot more in my studies on the topic for the last over a decade than you, a self professed "uninterested in Pa deer management" poster. lol.
Of course i sense a lot more "passion" on the topic coming from you than simply a casual uninterested poster as you initially claimed. Not a good foundation for establishing your initial credibility in this discussion. Perhaps we should clear that up. I have a interest first and foremost as a hunter, and secondarily as someone actually interested in states wildlife management strategies etc. What is your primary reason for interest?....
post edited by wayne c - 2011/02/04 17:37:39
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S-10
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RE: Deer Population Estimates
2011/02/04 17:17:02
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People constantly ask for science based management...well here it is right in front of your eyes. The PGC methods are not a joke this is the way science and statistics work, if you don't like the results then you don't like science based management period. No credible scientist or statistician would say that the population is declining given the estimates and variability. The above is all very true. Science based management is based on formulas, and assumptions and the variability is accepted by statisticians because they have no other choice. In the case of deer they don't know how accurate it is because they have nothing to compare the numbers too except more formulas containing more assumptions. The problems with the model as far as the hunter is concerned is it shows a stable herd from 2004-2009 even though the estimated buck harvest shows a decline for the same time period. The real interesting part is that both are based on the same original numbers, that being the comparison of the report cards and deer checked at the butchers. The other part is the model doesn't even reach it's peak accuracy for a given year until six years have passed and the data from those years can be plugged in. The scientists accept these limitations as part of life, The hunter says WTF. It's entirely possible that 5 or 6 years from now the scientist will look at 2006-2009 and say, guess what, the hunters were correct, the herd was declining.
post edited by S-10 - 2011/02/04 17:39:15
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wayne c
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RE: Deer Population Estimates
2011/02/04 17:30:35
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The problems with the model as far as the hunter is concerned is it shows a stable herd from 2004-2009 even though the estimated buck harvest shows a decline for the same time period. Not just the buck harvest which have indeed fallen drastically. But also most of the herd estimates in the annual reports for most wmus with supposed goals of stabilization.
post edited by wayne c - 2011/02/04 17:33:48
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deerfly
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RE: Deer Population Estimates
2011/02/04 17:37:56
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The other part is the model doesn't even reach it's peak accuracy for a given year until six years have passed and the data from those years can be plugged in. The scientists accept these limitations as part of life, The hunter says WTF.
Where does the six years of data come into play? I thought they corrected each years pre-hunt estimate based on that years harvest data? Or, are you referring to the statistical analysis they use to determine the population trend?
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S-10
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RE: Deer Population Estimates
2011/02/04 17:48:46
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As each year passes they plug in that years data which increases the accuracy and confidence of the previous years. There is a short explaination in the PGC link. Where things get mucked up a bit is changing things like they did with the brow tines. Somehow they will have to allow for that.
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deerfly
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RE: Deer Population Estimates
2011/02/04 17:55:41
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I wonder how they factor in the effect of the reduced antlerless allocations in a WMU like 2? The buck harvest rates from the antlered buck study were done when all of the units had a 2 week combined season and higher antlerless allocations a more deer, yet they are using those results for the basis for population estimates in all WMUs.
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wayne c
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RE: Deer Population Estimates
2011/02/04 18:37:08
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I donno, but i believe credibility of those implementing the science is a big issue. Many wouldnt believe rosenberry and his "direct supervisor"if they said the sky was blue. Understandable since they have been often known to tell quite a few apparent mistruths and have made quite a few deceitful damage control attempts. Have taken part in environut envdeavors, and have been pointed out in evelands report as being "problematic" figures within pgc, and also that at least one pgc commissioner has basically said they should not be employed at pgc any longer...
I know i will not trust them. Especially when most of what they say doesnt usually add up.
Also as for the plan, I in no way believe that they can totally fabricate a "vegetation based" management scheme from scratch....basically what amounts to a decade long experiment... They can also alter SAK model to fit antler restrictions... Yet they cannot better account for supposedly unintended further herd decline. Bull squat!
post edited by wayne c - 2011/02/04 18:40:59
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