Down

[Jackalope]

I ran some analysis to try and help illustrate how things are playing out with numbers with respect to the OH deer herd. Much of my data stems from the ODNR website with regards to harvest statistics by sex (buck vs. doe) by year (the ODNR has published the breakdown of harvest by buck, doe and button buck from 2009-2010 and 2010-2011 that was used in my analysis). In addition to that, because I couldn't find fawn mortality stats for OH, I used a study from the PA Game Commission. That said, I subtracted out the % of fawn mortality that the PA study attributed to black bear due to the lack of black bear population in OH. Lastly I found a study showing that there are approximately 140 fawns born per 100 whitetail deer on average. For the sake of my analysis, I gave OH deer a better success rate and said that every doe would produce 1.5 fawns per year.

The result is as follows:

In 2008 the ODNR estimated the herd at 700,000 deer. Assuming a 50:50 ratio of Buck to Doe at that time, that is 350,000 of each. In 2008, 90,552 bucks were killed, 129,247 doe were killed and 32,217 button bucks were killed. Based on numbers from the ODNR and assuming the 50:50 ratio, that means 227,230 bucks and 220,753 doe remained after deer season. 331,129 fawns would be born in spring of 2009 assuming each of the reaming doe produced 1.5 fawns each. Based on the PA study (less black bear related deaths), fawn mortality would be 41.5% leaving 193,565 surviving fawns. Assuming fawns are born at a ratio of 50:50 buck to doe, 324,013 buck and 317,535 doe were alive for the start of the 2009 season for a total of 641,548 deer.

In 2009, 93,873 bucks were killed, 133,988 doe were killed and 33,399 button bucks were killed. Therefore, after season, 196,740 bucks and 183,548 doe were roaming the state. Again assuming 1.5 fawns per doe meant 275,322 fawns would be born of which only 160,942 would survive (80,471 bucks and doe each). This means 277,211 buck and 264,019 doe would be in the state for the start of the 2010 season for a total of 541,230 deer.

In 2010, 86,046 bucks were killed, 122,815 doe were killed and 30,614 button bucks were killed. Therefore, after season, 160,551 bucks and 141,204 doe were roaming the state. At 1.5 fawns per doe, 211,805 fawns were born of which 123,813 would survive (61,907 bucks and doe each). This means 222,458 bucks and 203,110 doe would be in the state wide herd at the start of the 2011 season for a total of 425,568 deer in the state.

Therefore, as evident in this analysis, 3 seasons can easily take the state wide herd from 700,000 deer to 425,568 deer based on harvest statistics from the ODNR and other supporting studies. That is a 39% reduction in the herd. For doe specifically it is a 42% reduction from 2008 to the start of this season. Perhaps I have some inaccurate assumptions and I am more than happy to re-spin the analysis if anyone has factual information on the Buck to Doe numbers in the herd from 2008. Additionally, if someone has more accurate information on the number of fawns born per doe in OH annually or the fawn mortality % in OH, I can update and re-spin.

I didn't do this analysis assuming it is the word of the lord. I have highlighted my assumptions based on non ODNR studies as well as the factual harvest data from the ODNR. There is room for error in any analysis. That said, the point is simply to demonstrate how easily the herd in the state of Ohio can/could/is being reduced significantly in a very short period of time using information published by the ODNR and PA Game Commission.

OH SNAP.. lol.. Well done man.. Well done.

 

[jagermeister]

http://sfr.psu.edu/research/pacfwru/completed-projects-w/survival-fawns

Another study from PA... which suggests much lower predation rates, when black bears and bobcats are excluded of course.

"Within 34 weeks of capture, 106 of 218 monitored fawns died and 21 were censored. Of 98 fawns radio-tagged in 2000, 51 died within 34 weeks of capture and 7 were censored. Of 120 fawns radio-tagged in 2001, 55 died within 34 weeks of capture and 14 were censored. For both study sites combined, predation was the greatest source of mortality, accounting for deaths of 22.5% (95% CI = 17.6–28.8) of captured fawns and 46.2% (95% CI = 37.6–56.7) of mortalities through 34 weeks. Natural causes, excluding predation, were the second leading cause of death, accounting for deaths of 13.3% (95% CI = 9.5–18.6) of captured fawns and 27.4% (95% CI = 20.1–37.3) of mortalities. Vehicle accidents accounted for deaths of 9 fawns. Hunting accounted for deaths of 7 monitored fawns. Predation rates were greater in QWA, where 83.7% of predation events occurred. Mortality rates from other sources of mortality did not differ between QWA and PV, but 62.1% of deaths by natural causes, excluding predation, occurred in PV. We attributed 32.7% and 36.7% of predation events to black bears (Ursus americanus) and coyotes (Canis latrans), respectively. Bobcats (Lynx rufus) and unidentified predators accounted for 6.1% and 24.5% of predation events, respectively."


We could throw out hypothetical numbers until we're blue in the face, guys. You could suggest anything simply by changing the numbers around. What is it accomplishing?

 

[Ohiosam]

Huntn2
I don't know that your assumption that herd in '08 would be 50:50 buck doe would be correct. According to the ODNR in SE Ohio '08 it was better then 1.4 adult does per adult buck. Also there were .77 fawns per adult doe at the start of gun season in SE Ohio. see chart on page 5 http://www.dnr.state.oh.us/Portals/9/pdf/pub304_09.pdf
Funny after a few years of extra doe tags the ratio according to the ODNR increased to 1.56 adult does per adult buck and the fawns increase to .81. see chart on pg 5 http://www.dnr.state.oh.us/Portals/9/pdf/pub304.pdf

I can't speak to a validity of the numbers but these are the numbers used to justify the bag limits.

 

[huntn2]

http://sfr.psu.edu/research/pacfwru/completed-projects-w/survival-fawns

Another study from PA... which suggests much lower predation rates, when black bears and bobcats are excluded of course.

"Within 34 weeks of capture, 106 of 218 monitored fawns died and 21 were censored. Of 98 fawns radio-tagged in 2000, 51 died within 34 weeks of capture and 7 were censored. Of 120 fawns radio-tagged in 2001, 55 died within 34 weeks of capture and 14 were censored. For both study sites combined, predation was the greatest source of mortality, accounting for deaths of 22.5% (95% CI = 17.6–28.8) of captured fawns and 46.2% (95% CI = 37.6–56.7) of mortalities through 34 weeks. Natural causes, excluding predation, were the second leading cause of death, accounting for deaths of 13.3% (95% CI = 9.5–18.6) of captured fawns and 27.4% (95% CI = 20.1–37.3) of mortalities. Vehicle accidents accounted for deaths of 9 fawns. Hunting accounted for deaths of 7 monitored fawns. Predation rates were greater in QWA, where 83.7% of predation events occurred. Mortality rates from other sources of mortality did not differ between QWA and PV, but 62.1% of deaths by natural causes, excluding predation, occurred in PV. We attributed 32.7% and 36.7% of predation events to black bears (Ursus americanus) and coyotes (Canis latrans), respectively. Bobcats (Lynx rufus) and unidentified predators accounted for 6.1% and 24.5% of predation events, respectively."


We could throw out hypothetical numbers until we're blue in the face, guys. You could suggest anything simply by changing the numbers around. What is it accomplishing?

Jim, the study you referenced is the study used in my analysis. You only bolded the percent of fawn mortality attributed to black bear which I indicated I removed. I wasn't throwing out hypothetical numbers. I used publuished numbers by the ODNR and a neighboring state for fawn mortality. I had to make some assumptions with reproduction and as mentioned actually gave the OH reproduction an increase from what I found in a study. Therefore, if inflating the number of fawns thrown from each doe is throwing out hypotheticals, I am guilty as charged.

The point of the analysis as I mentioned is merely to illustrate how with our current harvest statistics it is very plausible that the state wide deer herd is not what we are led to believe it is. The point was to show by leveraging published harvest data how the herd can quickly be reduced based on the harvest rates we have seen over the past couple of years. The point was to include other variables we were not accounting for as this thread had progressed. Mainly, coyote, vehicle accidents, etc.

 

[huntn2]

Huntn2
I don't know that your assumption that herd in '08 would be 50:50 buck doe would be correct. According to the ODNR in SE Ohio '08 it was better then 1.4 adult does per adult buck. Also there were .77 fawns per adult doe at the start of gun season in SE Ohio. see chart on page 5 http://www.dnr.state.oh.us/Portals/9/pdf/pub304_09.pdf
Funny after a few years of extra doe tags the ratio according to the ODNR increased to 1.56 adult does per adult buck and the fawns increase to .81. see chart on pg 5 http://www.dnr.state.oh.us/Portals/9/pdf/pub304.pdf

I can't speak to a validity of the numbers but these are the numbers used to justify the bag limits.

Sam, great info! I can update the buck and doe numbers that I started with that make up the 700,000 deer in 2008 to be 312,000 buck to 437,500 doe (ratio of 1.4 doe to 1 buck). Problem is if I do that and I update the 1.5 fawns per doe I used to be .77 or .81 per those charts, the herd number is lower than what I originally projected going into this season...it drops to 346,903.

Not knowing specifically what the fawn to doe number is and a more accurate fawn mortaility % specific to OH is makes this tough. As Jim pointed out (which I was sure to call out from the start) this isn't 100% accurate. All I was doing is illustrating for folks with the harvest data how it is very feasible the herd can sharply be reduced.

 

[brock ratcliff]

Sam, great info! I can update the buck and doe numbers that I started with that make up the 700,000 deer in 2008 to be 312,000 buck to 437,500 doe (ratio of 1.4 doe to 1 buck). Problem is if I do that and I update the 1.5 fawns per doe I used to be .77 or .81 per those charts, the herd number is lower than what I originally projected going into this season...it drops to 346,903.

Not knowing specifically what the fawn to doe number is and a more accurate fawn mortaility % specific to OH is makes this tough. As Jim pointed out (which I was sure to call out from the start) this isn't 100% accurate. All I was doing is illustrating for folks with the harvest data how it is very feasible the herd can sharply be reduced.

Thank YOU! Nice work...

 

[jagermeister]

Jim, the study you referenced is the study used in my analysis. You only bolded the percent of fawn mortality attributed to black bear which I indicated I removed. I wasn't throwing out hypothetical numbers. I used publuished numbers by the ODNR and a neighboring state for fawn mortality. I had to make some assumptions with reproduction and as mentioned actually gave the OH reproduction an increase from what I found in a study. Therefore, if inflating the number of fawns thrown from each doe is throwing out hypotheticals, I am guilty as charged.

The point of the analysis as I mentioned is merely to illustrate how with our current harvest statistics it is very plausible that the state wide deer herd is not what we are led to believe it is. The point was to show by leveraging published harvest data how the herd can quickly be reduced based on the harvest rates we have seen over the past couple of years. The point was to include other variables we were not accounting for as this thread had progressed. Mainly, coyote, vehicle accidents, etc.

Well apparently I'm not interpreting the data the same way you are. The way I understand it, there was a mortality rate of fawns of 46.2%. Of that 46.2% mortality rate, 32.7% were caused by black bears and 36.7% were caused by coyotes. So, if 100 fawns were tagged, 46 of them died within the first 34 weeks. Of those 46 dead, 15 (33%) were killed by bears and 17 (37%) were killed by coyotes. So really, the overall mortality rate caused by coyotes alone is only about 17%.... not the 46% that you used in your calculations. Think about it man... If the mortality rate in PA for coyotes alone was 46%, how could they possibly have any deer left???

 

[Huckleberry Finn]

Someone buy that boy a new pocket protector for Christmas...damn

(Just busting your balls buddy, I love that you are able to convert your talents and intelligence into something that you love)

 

[brock ratcliff]

Mike Rex stated a bit ago that in the early 90's Ohio State did a predation study on his property and concluded they lost about 30%. I believe there are a lot more coyotes now than there was in the early 90's! It would be good to have a solid estimate from a recent study in Ohio...and I think even that can and will vary widely depending on the area(s) studied.

 

[RedCloud]

One thing that hasn't yet been mentioned is the fact that if the buck to doe ratio is 1:3 then only one of those doe is being bred while the other 2 run off, go into heat, and back out of cycle not being bred at all. What this gives you is the swing in numbers like I seen at my property where I can hunt just over 900 acres of continues ground. On this property 2 years ago we had a fair number of doe and few bucks and last year we had a decrease in doe numbers and an increase in buck numbers. This year we have seen a huge swing and are now seeing far more bucks then doe. In another thread I posted a study done by Brian Murphy that said this : Older Doe will toss a higher % of doe fawns while younger doe will toss a higher % of bucks. I can say this is fairly accurate by what I seen on my trail cams the last 2 seasons. I counted only 2 BB and 1 doe fawn last year on cam. This year I counted 4 BB and still only ONE doe fawn. Out of the 4 adult doe I have on cam this year only ONE is what I would call a mature doe in the 4-5 yo. age range while the other 3 are 1.5-3 yo. age range. One of the younger doe (3yo ?) had twins one BB and a doe. The BB she had is dead do to being hit by a car a couple months ago and that other fawn is the only doe fawn left to go into the next year unless she was shot during gun season. I will have to get the cams back out and running when I get home this weekend and start the annual after gun season inventory to see who is still up and running. So for my start of season next year given no deer was shot during gun season looks like 5 does and at least 10 bucks making a 2:1 buck to doe ratio. Keep going a few more years like this and my doe are going to be just like Beener's property where he has no doe but a boatload of bucks. No doe to breed with and the numbers start to fall as the bucks grow old and die or are shot with no fawns to replace them.

 

[huntn2]

Well apparently I'm not interpreting the data the same way you are. The way I understand it, there was a mortality rate of fawns of 46.2%. Of that 46.2% mortality rate, 32.7% were caused by black bears and 36.7% were caused by coyotes. So, if 100 fawns were tagged, 46 of them died within the first 34 weeks. Of those 46 dead, 15 (33%) were killed by bears and 17 (37%) were killed by coyotes. So really, the overall mortality rate caused by coyotes alone is only about 17%.... not the 46% that you used in your calculations. Think about it man... If the mortality rate in PA for coyotes alone was 46%, how could they possibly have any deer left???

According to that study, 51 of 98 died in 2000 and 55 of 120 died in 2001. That is 52% and 46% respectively. 46.2% of those deaths were due to predetors. So for 2000, that is 46.2% of 51 deaths (23.6 deer) died by predetors. Of those 23.6 deer, 32.7% were black bear, 36.7% were coyote, 6.1% were bobcat and the other 24.5% were unidentified predetors. Therefore, in 2000, 7.7 deer died from black bears (32.7% of the 23.6 deer that died by predetors). That means 43 deer fell by means other than black bear in 2000 (51-7.7). So, 43 deaths out of the 98 deer in 2000 equals a 44% mortality rate. I applied the same logic based on 2001 data to get to 41.5% mortality excluding black bears for the 2 year study. I figured all other elements would remain constant from PA to OH (vehicles, natural causes, coyote, etc.) and thus I used 41.5% mortality in my analysis.

Hope this helps clarify the math behind it for you.

 

[CJD3]

Huntn2- mail box is full

 

[huntn2]

Huntn2- mail box is full

Just cleaned it up some...Joe, can you increase my capacity man....dang!!!

 

[jagermeister]

According to that study, 51 of 98 died in 2000 and 55 of 120 died in 2001. That is 52% and 46% respectively. 46.2% of those deaths were due to predetors. So for 2000, that is 46.2% of 51 deaths (23.6 deer) died by predetors. Of those 23.6 deer, 32.7% were black bear, 36.7% were coyote, 6.1% were bobcat and the other 24.5% were unidentified predetors. Therefore, in 2000, 7.7 deer died from black bears (32.7% of the 23.6 deer that died by predetors). That means 43 deer fell by means other than black bear in 2000 (51-7.7). So, 43 deaths out of the 98 deer in 2000 equals a 44% mortality rate. I applied the same logic based on 2001 data to get to 41.5% mortality excluding black bears for the 2 year study. I figured all other elements would remain constant from PA to OH (vehicles, natural causes, coyote, etc.) and thus I used 41.5% mortality in my analysis.

Hope this helps clarify the math behind it for you.

Ahhh, got it bud. I should have known not to doubt the master of numbers. lol Sorry if I came off as being a dick... not my intent.

 

[Curran]

Damn. I've been gone since yesterday and had 6 pages to read through just to get caught up. Great discussion guys. Now I have to go to bed...

Huntn2 - very nicely done on the numbers.

 

[Jackalope]

No matter which way you slice the pie I think Ryan has shown beyond a shadow of a doubt that based on harvest numbers the deer population can be SEVERELY impacted in a very short manner of time.. Even if we went high and said his numbers we're off +/- 20% (which i don't believe they are) the fact remains he has proven beyond a doubt using ohio harvest numbers that it is not only completely feasible, but highly likely that our numbers could and have been drastically lowered.

 

[finelyshedded]

Great info guys! Thanks for crunching some numbers for us. It's really scary when you start adding the other kills like roadkills,poached deer, kill permits(not turned in), EHD(other diseases) and deer that simply just get shot and die and never recovered or even found!

The herd size number we're given every year might even be 50K higher than it actually is. Just sayin'!

Bottomline: The insurance companies are winning at the present.

 

[hickslawns]

It's really scary when you start adding the other kills like roadkills,poached deer, kill permits(not turned in), EHD(other diseases) and deer that simply just get shot and die and never recovered or even found!

Darn right!

Ryan- Impressive crunching of numbers. I would love to see someone from the ODNR step in with any additional information which might affect your statistics used. We all know numbers and statistics can easily be manipulated. I tried to look at your numbers and calculations from an unbiased standpoint. In doing so, I felt you were fair and conservative in your calculations and estimates for unknown variables. Not that my opinion matters and it is plenty possible I am not truly "unbiased". lol

Your time spent crunching numbers, coming up with graphs/tables/statistics, and ultimately your math prowess geekdom (teasing out of jealousy), are greatly appreciated!

 

[Kaiser878]

Kaiser....your a prick....only reason you kill deer is because they are pets....and you kill all your waterfowl in Tuscora park..........can I come hunt with you now?

BWAHAHAHA

Sure thing. Get ahold of me! ha

 

[Carpn]

One thing that hasn't yet been mentioned is the fact that if the buck to doe ratio is 1:3 then only one of those doe is being bred while the other 2 run off, go into heat, and back out of cycle not being bred at all. What this gives you is the swing in numbers like I seen at my property where I can hunt just over 900 acres of continues ground. On this property 2 years ago we had a fair number of doe and few bucks and last year we had a decrease in doe numbers and an increase in buck numbers. This year we have seen a huge swing and are now seeing far more bucks then doe. In another thread I posted a study done by Brian Murphy that said this : Older Doe will toss a higher % of doe fawns while younger doe will toss a higher % of bucks. I can say this is fairly accurate by what I seen on my trail cams the last 2 seasons. I counted only 2 BB and 1 doe fawn last year on cam. This year I counted 4 BB and still only ONE doe fawn. Out of the 4 adult doe I have on cam this year only ONE is what I would call a mature doe in the 4-5 yo. age range while the other 3 are 1.5-3 yo. age range. One of the younger doe (3yo ?) had twins one BB and a doe. The BB she had is dead do to being hit by a car a couple months ago and that other fawn is the only doe fawn left to go into the next year unless she was shot during gun season. I will have to get the cams back out and running when I get home this weekend and start the annual after gun season inventory to see who is still up and running. So for my start of season next year given no deer was shot during gun season looks like 5 does and at least 10 bucks making a 2:1 buck to doe ratio. Keep going a few more years like this and my doe are going to be just like Beener's property where he has no doe but a boatload of bucks. No doe to breed with and the numbers start to fall as the bucks grow old and die or are shot with no fawns to replace them.

One buck will bred multiple does....I doubt many does in Ohio make it thru the fall without a buck laying to them at some point ( excuse my technical terminology ..lol)