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How hunting is driving evolution in reverse...


Scott M

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Thought provoking article and a subject that I have thought about from time to time when I take to the deer stand.

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It's Survival of the Weak and Scrawny

by Lily Huang, Newsweek

Some of the most iconic photographs of Teddy Roosevelt, one of the first conservationists in American politics, show the president posing companionably with the prizes of his trophy hunts. An elephant felled in Africa in 1909 points its tusks skyward; a Cape buffalo, crowned with horns in the shape of a handlebar mustache, slumps in a Kenyan swamp. In North America, he stalked deer, pronghorn antelope, bighorn sheep and elk, which he called "lordly game" for their majestic antlers. What's remarkable about these photographs is not that they depict a hunter who was also naturalist John Muir's staunchest political ally. It's that just 100 years after his expeditions, many of the kind of magnificent trophies he routinely captured are becoming rare.

Elk still range across parts of North America, but every hunting season brings a greater challenge to find the sought-after bull with a towering spread of antlers. Africa and Asia still have elephants, but Roosevelt would have regarded most of them as freaks, because they don't have tusks. Researchers describe what's happening as none other than the selection process that Darwin made famous: the fittest of a species survive to reproduce and pass along their traits to succeeding generations, while the traits of the unfit gradually disappear. Selective hunting—picking out individuals with the best horns or antlers, or the largest piece of hide—works in reverse: the evolutionary loser is not the small and defenseless, but the biggest and best-equipped to win mates or fend off attackers.

When hunting is severe enough to outstrip other threats to survival, the unsought, middling individuals make out better than the alpha animals, and the species changes. "Survival of the fittest" is still the rule, but the "fit" begin to look unlike what you might expect. And looks aren't the only things changing: behavior adapts too, from how hunted animals act to how they reproduce. There's nothing wrong with a species getting molded over time by new kinds of risk. But some experts believe problems arise when these changes make no evolutionary sense.

Ram Mountain in Alberta, Canada, is home to a population of bighorn sheep, whose most vulnerable individuals are males with thick, curving horns that give them a regal, Princess Leia look. In the course of 30 years of study, biologist Marco Festa-Bianchet of the University of Sherbrooke in Quebec found a roughly 25 percent decline in the size of these horns, and both male and female sheep getting smaller. There's no mystery on Ram Mountain: male sheep with big horns tend to be larger and produce larger offspring. During the fall rut, or breeding season, these alpha rams mate more than any other males, by winning fights or thwarting other males' access to their ewes. Their success, however, is contingent upon their surviving the two-month hunting season just before the rut, and in a strange way, they're competing against their horns. Around the age of 4, their horn size makes them legal game—several years before their reproductive peak. That means smaller-horned males get far more opportunity to mate.

Other species are shrinking, too. Australia's red kangaroo has become noticeably smaller as poachers target the largest animals for leather. The phenomenon has been most apparent in harvested fish: since fishing nets began capturing only fish of sufficient size in the 1980s, the Atlantic cod and salmon, several flounders and the northern pike have all propagated in miniature.

So what if fish or kangaroos are smaller? If being smaller is safer, this might be a successful adaptation for a hunted species. After all, " 'fitness' is relative and transitory," says Columbia University biologist Don Melnick, meaning that Darwinian natural selection has nothing to do with what's good or bad, or the way things should be. Tusks used to make elephants fitter, as a weapon or a tool in foraging—until ivory became a precious commodity and having tusks got you killed. Then tuskless elephants, products of a genetic fluke, became the more consistent breeders and grew from around 2 percent among African elephants to more than 38 percent in one Zambian population, and 98 percent in a South African one. In Asia, where female elephants don't have tusks to begin with, the proportion of tuskless elephants has more than doubled, to more than 90 percent in Sri Lanka. But there's a cost to not having tusks. Tusked elephants, like the old dominant males on Ram Mountain, were "genetically 'better' individuals," says Festa-Bianchet. "When you take them systematically out of the population for several years, you end up leaving essentially a bunch of losers doing the breeding."

"Losers" tend not to be very good breeders, meaning that this demographic shift ultimately threatens the viability of a species. Researchers also worry that the surviving animals are left with a narrower gene pool. In highly controlled environments, a species with frighteningly little genetic diversity can persist—think of the extremes of domesticated animals like thoroughbred horses or commercial chickens—but in real ecosystems changes are unpredictable. Artificially selecting animals in the wild—in effect, breeding them—is "a very risky game," says Columbia's Melnick. "It's highly likely to result in the end of a species."

At present, researchers' alarm about these trends are based on theories that are hard to prove. To make scientific claims about the effects of hunting on the evolution of a species, researchers like Melnick would need thorough data from animal populations that lived at least several decades ago, which rarely exist. Evolution, it turns out, is a difficult beast to study in real time because it is the product of so many factors—changes in climate, habitat and food supply, as well as gene frequencies—and because it occurs so slowly. Researchers began tracking sheep on Ram Mountain in the early 1970s, corralling the entire population every year to make measurements and trace genealogies. "You cannot really just go out and take data and look for a trend," says Festa-Bianchet. "Even if you find a trend it can be due to environmental changes, to changes in density. You're really trying to tease out the genetic part of the change."

The time scale is one reason that most wildlife departments managing hunting harvests simply count the heads each year and decide how many to let hunters bag without thinking about genes. The most popular method of regulating hunting—restricting legal game to males with a minimum antler size—results in populations overrun with females and inferior males, which is ultimately no service to hunters. "The hunters wish for animals with large antlers and large horns, and yet their actions are making that harder to achieve," says Richard Harris, a conservation biologist in Montana. As a hunter, Harris knows that the outcome of this trend will satisfy no one, the Teddy Roosevelts of the next generation least of all.

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I think if you make hunting too easy or if habitat is shrunk way down and it becomes too accessible, then the risk of losing the larger and more desirable individuals and their genes is more likely. I think it’s the charge of fish and wildlife biologists and managers to make these decisions. Poaching isn’t helping, like in the case of the African elephants. Too many tags are probably hurting the mountain sheep example if too many large rams are being felled. I don’t think you can make the blanket statement across the board that large trophy big game or fish are disappearing. If that was the case, the record books (B&C, P&Y, Tackle and Line Class records) wouldn’t be changing and trophies and new world records would be a thing of the past. That just isn't the case. The elk example is way off. There are still plenty of large elk being shot out west. Think of white-tails in the Midwest. Every year there are more and more large individuals that take on media celebrity status. The hole in the horn buck, the field and stream buck, the amish buck, etc. etc.

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pure antihunting b.s.....theodore roosevelt saved many northamerican species from extinction by forming the boone and crockett club with conservation and hunting laws,limits and ethics. don't believe a newsweek reporter whose only seen a wild animal at the bronx zoo. deer for example get bred multiple times by multiple bucks not just by the ones with the biggest antlers, if it was only the largest all the does in minnesota wouldn't get bred.

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Makes sense to me. Evolution has a funny way about her. Look at birds for an example. There are species of birds, wish I could name them, that their beaks have evolved to what food source is available. Stands to reason you take out a dominant gene over time evolution takes over and says best way to survive go smaller and less desirable to the predator that most hunts it. This isnt a matter of extinction its a matter of a species change over time to adapt to its surrounding.

Nope not an anti. Just thought it was an thought provoking read that shows merritt for consideration.

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Northern pike are getting smaller because of netting? Seems unlikely. Mostly because of anglers and harpooners taking the big ones and leaving the little ones alone until there are a gazillion little ones and no big ones.

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Sounds feasible human interference with ma nature!

Just look at the mind set in the deer forum!! Let the small racks pass take a Big racked deer,so the smaller ones grow.

Darwin couldn't be all wrong.I dont think its all removing the genes,but survival of the best adapted,which seems to be smaller racks.

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Northern pike are getting smaller because of netting? Seems unlikely. Mostly because of anglers and harpooners taking the big ones and leaving the little ones alone until there are a gazillion little ones and no big ones.

Most of the spearers out there arent only taking big ones, you should look at the spearing section on there its the opposite pretty much

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How big were male humans in the early 1800"s? How big were the people purple eaters vrs now? Things change in life every day people. I'm not saying that we do not have an effect on some things in nature because we do , but hunting and fishing, come on..

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Quote:
Evolved?? Sounds to me more like adaptation

Adaptation would be when some of the birds with beaks that are better suited for the food source are able to survive and reproduce more successfully than the rest of the species. Over time, those birds reproduce with birds with similar beaks, pretty soon the whole population has the same beak structure that helps them survive better, and the birds without the needed beak structure die out. Through the adaptation, the birds beaks have evolved over generations and can be totally different from the same species in a different location, ala Darwin's finches on the Galapagos Islands.

As for hunters causing reverse evolution. Not buying it. Too many good critters make it through and we never see them. Not too well read on sheep and kangaroo to really know what their breeding habits and maturity times are though, so I can't comment on them.

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The tragedy is that hunters, fisherman, and environmentalists while working for approximately the same thing can never agree on anything.

We need a return to conservationist.

If you keep killing the biggest, then the smaller have an evolutionary advantage. Due to selective breeding the herd gets smaller. You see the same thing in dogs: want a smaller dog, breed to smaller dogs together. If the larger ones have no option to breed their large genes disappear.

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Consider the difference between pheasants and deer. The pheasant roosters get hunted hard, the dumb and the slow are shot, and only the smartest and strongest survive to breed the next spring. Deer on the other hand, hunters selectively harvest the deer with the biggest racks. Some of them get to breed before they are shot but a lot of the smaller bucks also get to breed. BUT that doesn't mean that the smaller buck is passing on inferior genes, give him time to grow and he'll probably grow big antlers too.

I think where the theory in the article falls flat as far as whitetails go is that a lot of the small bucks also get shot, there is no advantage gained to having small antlers. As 96trigger described so well, in order for small antlers to evolve and dominate, there would need to be a biological advantage for small bucks, and that isn't the case.

I think the article was a blantant anti-hunting article pandering to the yuppies that read Newsweek.

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I feel the article could quite possibly paint another negative picture on hunting to those that are ignorant to wildlife biology/ecology (in other words, people that read one article and can't think about other points to the story and take it for gospel. Hmm, imagine that?). Any study can be done with a chance that anything could be affecting something depending on who's doing the study and what they are trying to prove.

I personally don't buy a lot of the story as there are SOOO many other factors (which they do state)to take into consideration for a population to change and pinpoint it to hunting. This is just not quantifiable in my book.

However the main point is that I really don't think that we have to worry about this with our MN deer herd. #1 in order for this to happen, we'd have to let a good portion if not vast majority of our bucks reach full maturity. I'm not talking about 2.5-3.5 yrs old but probably a min 4.5-5.5 yr. old and I'm talking over a very, very large area, not just Joe's back 40. As mentioned above however, a lot if not the majority of the immature bucks have great genetics to produce large racks.

We'd then have to only focus on those fully mature bucks and then not knowing, pass on the ones that look like they aren't as mature due to them having smaller racks. This would have to be based on assuming that they have a sufficient amount of nutrients when they needed it to eliminate that factor from being a limiting factor for growing large antlers. Individual genetics being then the main limiting factor not allowing bucks to be as big as other bucks of their own age class that we'd consider "takers".

I'm not saying this is bad or good but MN has many, many of it's bucks getting shot before they reach their FULL maturity or maximum antler growth potential. Once again, not saying I am in favor of this but the talked about antler point restriction (lets assume 4 on a side) would allow for the taking of many non-fully mature bucks. Heck there are a lot of bucks that would make a 4 point side restriction at 1.5yrs old if not 2.5yrs.

Even many people practicing QDM are havesting very nice 3.5yr old deer. Still probably a year or two away from being at full potential.

Now on some large, large properties maybe, maybe possible. Let's take big Texas Ranches for example. Many of those intensively managed ranches know their deer herd inside and out and practice "culling" bucks that they know are at full maturity and just don't have the genetics of others buck of the same age class with larger racks. Now is that because they are "inferior" or just because they only want the absolute "cream of the crop" to be spreading genetics around. I'll you come up with you own answer to that one.

Point being, I don't think we have to worry about our deer herd in MN being inadvertently surpressed due to the over harvest of large mature deer.

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The one big IF in the entire article, is IF we can take out the largest/biggest animal in the herd consistently/accurately. If there wasn't a complete census on the entire animal population, how would we ever know.

Habitat and Age, have a much bigger/easier to determine effect on this sort of thing.

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In PA where I used to live they have antler restrictions. Deer hunting is big there, close to 1 million people in the woods on opening day. It used to be you shot the first deer you saw, well 90% of people did. If you listen to what they say about the reasons for the restrictions it was to develop an older herd. The older herd provides for a more healthy/stable herd for lots of reasons. They also took out many does from the herd.

The CO's wore bullet proof vests when explaining the rules changes. Many people are still mad 10 years or so later because they say they don't see any deer. It some ways they are right. Many people have filed lawsuits saying they've screwed up the herd there. The problem is most people were killing 1.5 year old deer. In the area I grew up in the deer must have 4 points one side (each 1" or longer). To get that many the deer must be 2.5+ yrs old. That extra year makes them a lot smarter but the hunters haven't changed their hunting habits. They go out and sit in the same spot and expect the older deer to make the same mistakes the 1.5 yr old used to. That's just not going to happen. Anywhere you live the old deer get old because their smart. The CO's will tell people that but everyone thinks they are just making excuses for killing of all the deer.

I don't agree with the article. I actual believe in some areas there's a law that the ram's horns have to be a certain length before they can be shot and if you shoot under the length you can be fined. I highly doubt the other rams recognize that the older ones with longer horns are getting shot. Maybe it's just me but I doubt that this rational thinking enters their head.

The over population of females is only a problem for hunters when all people want to shoot is males. Since whitetail deer breed with as many does as possible you generally can't control population by killing bucks you do it by killing does. That's why your bonus tags are for does not bucks.

Also, I believe that in areas with exceptionally high deer densities the does can determne the sex of the fawn and will reproduce bucks so they don't have to compete with other does for prime birthing/calving habitat. I just re-read this in a book I have to verify this. In fact it also states that in good habitat and low populations they produce more does to increase the herd size. They self regualte for their own survival, as best they can.

I trust the Wiildlife Biologists that wrote the book I just re-read versus the person that wrote this article.

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