What kills WI deer?

[David Petersen]

#7102

Researchers in Wisconsin looked at the leading causes of deer mortality: human hunting 43%, starvation 9%, poaching 8%, coyote 7%, wolf 6% and roadkill 6%. I’d sure like to see a report like this for every state. It might change the nature of certain persistent arguments. 😀

http://www.jsonline.com/sports/outdoors/study-sheds-light-on-top-causes-of-deer-mortality-b99190938z1-241992741.html

[James Harvey]

#58432

Dave, I found the figures on the related fawn study interesting too…

The researchers tracked the fawns daily through summer. The eight-week survival average is 58% for fawns in the northern study area and 76% in the eastern farmland.

Of the fawns that died in summer in the northern study area, 79% were taken by predators. Black bears led the way, killing nine fawns, followed by coyote (six) and bobcat (six). Unknown predators accounted for 11 fawns.

In the eastern farmland study area, the leading cause of fawn mortality was starvation and other natural causes (50%), followed by predators (36%). Of the deaths linked to predators, coyotes killed 8 fawns, followed by bear (one), bobcat (one) and domestic dog (one). Unknown predators accounted for four fawn deaths.

I’m impressed by the black bears and bobcats, those are two animals I did not have in my head as deer slayers, but we do tend to think about animals as mature adults, not vulnerable fawns (at least I do).

Am I right in remembering your mate Valerius Geist writing that the single best change that could be made to the elk hunting paradigm (in terms of herd health) would be to shift the human focus from mature males to fawns as that historic hunter of elk fawns, the wolf, no longer shares much of the elk range? As I understood it that lack of fawn mortality combined with the unprecedented pressure on mature males has created an ecological imbalance?

All the same fawn mortality (and joeys here) strikes me as an underappreciated facet of herd biology.

Thanks for the link 😉

Jim

[Don Thomas]

#58483

Back when I lived on the Kenai Peninsula, the local biologists–good friends of mine–were studying this issue closely. They showed that 50% of the moose calves born in GMU 15A were killed during their first 10 days of life, not by wolves, not by brown bears (there were plenty of both) but by black bears. In southern Africa, the most efficient predator on ungulates is the diminutive caracal, a felid roughly the size of our bobcat. Two points: 1. The predators that do the most predation are not necessarily those one would first assume. 2. So what? Bears, canids, and felids have been killing moose, deer, and impala for millennia. Sudden changes in predator-prey dynamics are almost always due to multiple factors. Don

[Fallguy]

#60208

It seems according to this study in WI. that W@#ves do not even rate #1 in the 4 legged predator category. I know they get the most press and credit around here for deer numbers being down. It looks like the numbers do not seem to support the claims. To bad we can’t get past our Red Riding Hood fears from childhood.

[Anonymous]

#62637

David Petersen wrote: Researchers in Wisconsin looked at the leading causes of deer mortality: human hunting 43%, starvation 9%, poaching 8%, coyote 7%, wolf 6% and roadkill 6%. I’d sure like to see a report like this for every state. It might change the nature of certain persistent arguments. 😀

http://www.jsonline.com/sports/outdoors/study-sheds-light-on-top-causes-of-deer-mortality-b99190938z1-241992741.html

True, but you assume that facts actually matter when hysteria takes over.

[James Harvey]

#62787

Don, it’s fascinating any time an unseen part of the world is opened up, especially when it doesn’t match up with expectations. Even if that is just ‘unseen and unexpected by the ignorant’ because that’s me 😉

[David Fudala]

#23762

What you have to be careful of when you see a study like this is the fact that the numbers are a bit skewed. In order to accurately account for a certain predators impact on a prey species you have to keep the counts within the boundaries of that predators range. These numbers, while a good start, are state wide ratios. Wolves and bears do not inhabit the entire state while people and deer do. So those numbers would shift a bit if you were to focus on percentages specific to the occupied ranges of wolves and bears. But, like I said, its a good start.

[Anonymous]

#25185

Dfudala wrote: What you have to be careful of when you see a study like this is the fact that the numbers are a bit skewed. In order to accurately account for a certain predators impact on a prey species you have to keep the counts within the boundaries of that predators range. These numbers, while a good start, are state wide ratios. Wolves and bears do not inhabit the entire state while people and deer do. So those numbers would shift a bit if you were to focus on percentages specific to the occupied ranges of wolves and bears. But, like I said, its a good start.

Agreed. There is an old saying about research data that “you can either torture the data until it confesses what you want, or you can question it admits the truth regardless”. In this study, the cross-examination has only begun and not enough data is being questioned.

Trust me, I say this coming from a place that has a reputation for doing the latter but FAR too often is only interested in the former (to advance agendas). The latter is valuable; the former dangerous.

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