One of the few times I wish I had paid more attention in statistics class. I cannot for the life of me remember anything about calculating correlation. Anyway, it's a pretty graph.

http://www.acorn-online.com/joomla15/index...&Itemid=778

Deer-hunt kills increase, deer-car crashes decrease: Is change related?

Road kills of deer in town have declined dramatically over the last decade, as the number of deer taken by hunters has risen.

“If you kill deer by hunting them, you get fewer car accidents,” Conservation Commission Chairman Ben Oko said. “That seems very clear.”

But a vast lowering of deer numbers — the culling of five out of every six deer now roaming Ridgefield’s forests — would be needed to bring the population down to levels that research has found can make a difference in keeping down ticks and Lyme disease.

The state counted 122 deer road kills in 1998, and just 35 in 2008. Deer taken by archery hunting rose from 55 in 1998 to 222 in 2008.

The pattern holds — with some ups and downs — across the 12 years from 1996 to 2008, according to statistics assembled by Howard Kilpatrick, a wildlife biologist with the state environmental department.

And Ridgefield no longer leads the state in the number of deer killed on its roads.

“Ridgefield was consistently ranked number one for many years — it was for three, four, five years anyway,” Mr. Kilpatrick said. “In 2007, they were ranked number seven.”

Ridgefield Police count more road deaths of deer than does the state, but the trend is similar. Road kills fell from 205 seven years ago to 90 last year, according to Police Chief John Roche.

Annual road-kill totals from 2001 to 2008 were: 205, 129, 172, 198, 146, 115, 127, 90.

No method of counting deer — hunted, killed on the roads, or running in the woods — can be taken as 100% accurate, Mr. Kilpatrick said. His numbers are based on Deer Kill Incident Report forms that police all across the state fill out when they go to the scene of an accident.

The higher numbers from the Ridgefield Police include those incidents, but also count carcasses found along roads when no accident is reported.

Mr. Kilpatrick’s numbers on deer harvested are based on tags turned in by hunters, and are likely low since not all hunters turn them in. Still, he said his numbers were meaningful because the methodology was consistent over the 12 years.

“We know the reported harvest is low. We know the reported deer road kills are low,” he said. “But our method for collecting that data is the same, so any trends should reflect what’s really happening out there.”

“What Howard is saying is that there is still a correlation, whether it’s reported as what he had, or what we had,” Chief Roche said. “There is still a drop in the number of deer found dead on the side of the road.”

Town hunt

The trends Mr. Kilpatrick documented began before the town started allowing hunters on its open space lands. The town program started as one-site demonstration hunt in 2006 and expanded to five parcels in 2007, and seven in 2008, with most locations limited to archery but some gun hunting.

Mr. Kilpatrick’s count includes the town hunt, but also deer hunted on state land — the Great Swamp and, more recently, at Bennett’s Pond — as well as private property.

“While the state chart demonstrates an apparent direct correlation between hunting and the decline in road kills, the impact of the town’s hunt on the numbers is too early to determine,” said Tom Belote of the town’s Deer Management Committee.

But hunting in general?

“You can only learn one thing from this, I think,” said Ben Oko of the Conservation Commission, “and that’s that if you harvest deer in substantial numbers you will decrease road kill, or car accidents.”

Ticks, Lyme disease

People backed the town hunt, said First Selectman Rudy Marconi. “One of the largest town meetings we’ve ever had. Over 700 voted,” he said. “It was an overwhelming show of support for us to do something.”

Car accidents weren’t the main concern.

“The control of Lyme disease is probably the single most important thing from a health perspective,” Mr. Marconi said. “We have a tremendous number of Lyme disease cases in town, and we need to take every actionable step we can. Although the deer doesn’t cause the tick, it is the vehicle which allowed the tick to travel.”

Mr. Kilpatrick points to studies from two areas of Groton in eastern Connecticut, Bluff Point State Park and Mumford Cove, that suggest aggressive deer control may reduce both the tick count and Lyme disease rates.

“When we dropped the deer population on Bluff Point from 230 per square mile to 50, we did see a change in tick densities,” Mr. Kilpatrick said.

State studies of the Mumford Cove community on a nearby peninsula showed the correlation to Lyme disease. “The deer population was reduced from about 70 per square mile to about 10 to 12 per square mile,” Mr. Kilpatrick said.

“A community of about 100 households, we surveyed the community over a 13-year period. What we found is the number of cases of Lyme disease reported by residents dropped from 22, 23 a year to down to two to five a year.

“Over a 13-year period we had documented, you can reduce human risk of Lyme disease by reducing the deer down to 10 to 12 per square mile,” he said.

State aerial photo surveys of the deer population suggest Ridgefield has a way to go to reach levels that have shown a reduction in Lyme disease.

“We observed about 31 deer per square mile, but a more realistic estimate is 62 deer per square mile,” Mr. Kilpatrick said of Ridgefield. “You miss about half the deer out there when you count.”

The deer committee catalogued the problems from deer overpopulation: car accidents, Lyme and other tick-borne diseases, damage to home plantings, and overbrowsing of open space.

“The reduction of the number of vehicle/deer collisions becomes apparent first,” Mr. Belote said. “It will take at least five or more years to assess the impact of deer reduction as it relates to damage to the open spaces. Reduction in tick-borne diseases will take longer.”

Are those numbers right? 230 deer per square mile? That's a lotta deer!

The science of wildlife counts, for some reason, I find facinating.

if it's right, thats a hell of a lot of deer

I question the source of this article. A hunting advocate perhaps? The answer is simple Dear Watson. Fewer cars on the road due to high cost of gas, also, with people losing their homes to foreclosure, many are also turning in their vehicles as they can no longer afford payments.

The state counted 122 deer road kills in 1998, and just 35 in 2008

Duh. Whatd I tell ya.

The control of Lyme disease is probably the single most important thing from a health perspective,” Mr. Marconi said. “We have a tremendous number of Lyme disease cases in town, and we need to take every actionable step we can. Although the deer doesn’t cause the tick, it is the vehicle which allowed the tick to travel.”


Ticks are now hitching rides on cars?

One reader's comments:

Whoa! Careful there all you big guys with the guns. You can't just look at a graph and say, "See there is a correlation."

There are more rigorous mathematical approaches to show correlation. And when I run the numbers for your deer kill scenario, it shows a -1% correlation. This is mathematically insignificant. You are looking for a correlation number of about 70% for your conclusion to be valid.

I am hopeful that the culling of the deer herd will have an impact, but pretty pictures aside, the data does not yet support the claim that the number of car accidents are going down because of the hunt.

Let's not jump the gun, so to speak.

I doubt those numbers are accurate, as is evidenced by the rest of the article's inaccuracy. Ticks riding in cars, scratching their heads over the decreased number of roadkill. I wouldn't be surprised if their main roadways have been under construction for the past few years and closed to through traffic.

I could find some more studies for ya, Grace, if you'd like.

There's a local example of the this factoid.
Our local colledge doesn't allow any hunting in the woods around it. As a result; the deer pile into the woods. There's hardly any underbrush left, but that's another story.

Now; which roads in the local area have the most deer-car collisions?

oddly enough; the roads bordering the 'safe-haven' woods.

Didn't see that one coming.....

Iowa

Yes please. By PETA.


Iowa

That's a loaded question and highly unfair. How the hell do I know the name of roads in Iowa?

Iowa

Didn't see what coming?

By the way, did you see that newly discovered cloud formation over Iowa that some Iowan snapped the other day? Has the scientists practically having a name that cloud contest. It was on Yahoo's main site but probably scrolled off (today).

If that cloud was over the folks across the street from us; what they were seeing was Bar-b-q gone pysco. It's little short of amazing they didn't set thier house on fire.

And they didn't invite me.

Regarding the deer #'s= more car-venison, the numbers seem to be pretty consistant, Grace. HOW much the increase is can be discussed, I reckon and there are certainly folk who perfer non-lethal means to reduce such.

Isn't the author himself confusing correlation and causation?

Yes. I can go with that.

Hi all, been a long time. How many road kills? Is this total for the state---if so I can't believe it---per square mile, I believe it. I live on the Eastern shore of MD, not far from the VA border and this place is loaded with deer-- our hunting limits allow what--10 does and two bucks per season, muzzeloader, shotgun/rifle, and second muzzeloader (36 TOTAL)+ assateaque and sika + western MD. This part of the countrfy is loaded with them. Have claimed two so far by car.

When growing up in the eighties I drove from MD to NC a lot to go surf fishing on Hatteras Island, I loved driving at night due to low traffic. Now I can't
stand driving at night due to the increased deer population. It's not a matter of if anymore but when over hear.

This die hard travelling fishermen just recently got into deer hunting last fall and love it. It's almost religion here and I look foreward to putting my Colombian wife in a tree stand with me this year--if she can handle the cold.

Hello Marlin. I am sure that she will suffer the cold for a taste of deer meat and after the first one she will most likely be bugging you to take her hunting..

Here's another take on the same theme......
http://www.kansascity.com/news/neighborhoo...ml?storylink=pd