Thanks for posting the data tables Joe!
As Joe mentioned I compiled data for Ohio deer-vehicle accidents. The threads we have had throughout the 2011-2012 deer season discussing hunter perceptions of the Ohio deer population have led me to run analysis to better understand and illustrate what the herd population may be.
I already shared an analysis that illustrates the herd size may be less than the ODNR’s estimates. In that analysis I used harvest data, fawn per doe ratio, and buck to doe ratio data published by the ODNR. In addition to this information, I leveraged a fawn mortality study by the Pennsylvania Game Commission to incorporate another contributing factor that impacts the deer population besides hunter success. When I posted the results of this analysis I stated there are still many other variables that I hadn’t accounted for.
After spending another weekend in the woods without seeing a deer I decided to dig into one of those additional variables. As Joe posted, I pulled deer-vehicle accident statistics from the Ohio Insurance Institute. I reviewed deer-vehicle accidents by county and year from 2002 – 2010. The statewide result is deer-vehicle accidents are down 23% in 2010 compared to 2002. This alone was staggering but I began to ask myself several follow-up statements/questions that could contribute to significantly fewer deer-vehicle accidents. Some of the questions I began to ponder are as follows:
- Perhaps there are fewer licensed drivers in Ohio in 2010 than there were in 2002
- Perhaps with higher gas prices and tough economic times, drivers are traveling less miles annually
- Perhaps the introduction of smart phones with e-mail, texting, web and social media capabilities have made drivers more attentive to the road, other vehicles and potential hazards…
- Perhaps there are simply fewer deer to become a statistic when it comes to vehicle accidents
From my personal observations, analysis and logs over the past few seasons, my belief is there are fewer deer. Obviously my 3rd question was more of a joke. I believe society is more distracted then ever behind the wheel and technology is a contributing factor. So I felt I should research the 1st and 2nd elements for a correlation to fewer deer-vehicle accidents. I pulled data from the US Department of Transportation Federal Highway Administration. The results are as follows:
- There are 3.31% more licensed drivers in Ohio in 2010 compared to 2002
- There are 136% or 63,693,000,000 more annual vehicle miles traveled in 2009 compared to 2002 in Ohio (I didn’t see the 2010 figure yet so I used 2009)
While licensed drivers and vehicle miles have increased in Ohio, and in the case of the miles, increased significantly, the deer vehicle accidents have decreased sharply. Therefore, I fall back to my original gut instinct; there may just be less deer in Ohio enabling fewer deer-vehicle accidents.
The last action I have taken at this time is to factor deer-vehicle accidents into my herd population estimate calculation. Though not every deer involved in a vehicle accident dies, I have made the assumption that those reported do. I felt comfortable with this assumption since not all accidents are reported to begin with. I also assumed a 50:50 buck to doe ratio for accidents. Adding deer deaths due to vehicle accidents to the harvest data, fawn mortality due to predation, and fawn per doe ratio decreases the herd by another 193k from 2008 – 2011.
Perhaps deer-vehicle accidents have no correlation to the herd population. I will leave that up to each of you to decide for yourself. I am simply trying to take available data to illustrate what may be the reality of the OH deer population. More importantly, I am trying to take available information to create a more accurate method of estimating the deer population. Maybe those who are observing less deer aren’t crazy, lazy, or bored by the ease of harvesting whitetail deer. There may actually just be less deer. That is after all the goal of the ODNR’s management plan. So the question becomes, have levels been dropped too far?
I plan to build on my analysis as time permits and I also have hopes of summarizing it and presenting it to Mike Tonkovich and team at the ODNR. I am sure they will be able to help me understand where my assumptions/variables may be flawed as well as provide other factors that should be considered.
Ryan