Maggie Fox

Washington - Hunting and gathering has a profound impact on animals and plants, driving an evolutionary process that makes them become smaller and reproduce earlier, US researchers reported on Monday.

Their study of hunting, fishing and collecting of 29 different species shows that under human pressure, creatures on average become 20% smaller and their reproductive age advances by 25%.

The human tendency to seek large "trophies" appears to drive evolution much faster than hunting by other predators, which pick off the small and the weak, the researchers report in the Proceedings of the National Academy of Sciences.

"As predators, humans are a dominant evolutionary force," said Chris Darimont of the University of California, Santa Cruz. "It's an ideal recipe for rapid trait change."

Natural selection

Darimont and colleagues calculated the rates of trait change with a metric called the "Darwin", after Charles Darwin, who developed the theory of natural selection to help explain evolution.

They studied changes in the size of fish, limpets, snails, bighorn sheep and caribou, as well as two plants - the Himalayan snow lotus and American ginseng.

In virtually all cases, human-targeted species got smaller and smaller and started reproducing at younger ages - making populations more vulnerable.

"Earlier breeders often produce far fewer offspring. If we take so much and reduce their ability to reproduce successfully, we reduce their resilience and ability to recover," Darimont said.

Super-predator

The findings fit in with other studies that suggest many fish are over-harvested.

"The public knows we often harvest far too many fish, but the threat goes above and beyond numbers," Darimont said in a statement.

"We're changing the very essence of what remains, sometimes within the span of only two decades. We are the planet's super-predator."

Regulations meant to protect the young may in fact be helping drive this unnatural process, Darimont said.

"Hunters are instructed not to take smaller animals or those with smaller horns. This is counter to patterns of natural predation, and now we're seeing the consequences of this management," he said.

- Reuters

PC BS

This statement is true on its face but does not go far enough. It is not sportfishing that has caused the demise of fish stocks it has been commercial fishing.

As for size of fish, the sport fisherman realized the size of fish were going down a long time ago and now are doing more catch and release.

Commercial fishing does not discriminate. Example, recent Blue fin tuna sold for $100,000 in Japan.

Here in the U.S. and I am sure in places in Africa this holds true. But, because of proper Game management, we are seeing larger horned/antlered animals all the time. New world records are being produced all the time. It is when we have indiscrimate overharvesting of wildife is where we get in trouble.

It is important to remove these older aged animals that are no longer breeding and improving the gene pool. They have already done there job. That is what good game managment is. When we go for maxium sustainable harvest that is when we get in trouble. A few states come to mind, Oregon, Washington, and Colorado. Their herds are still quite large but they still had problems until they changed there management style.

It happened in the state of Washington with their elk herds. They were harvest was so high, it was rare that you saw anything above a spike bull being harvested in some areas. Calf survival was poor. The cow/calf ratio was low. In some areas there was only a 5 percent survival of bulls and those were spikes. Most Bull elk never survive beyond 3 years of age. They changed their managment style to allow for at least 15 percent or more escapement of adult bulls. This meant five year old bulls and above. This allowed for increased calf survival plus greater cow/calf ratio. Now they are producing more elk, harvest is up and trophy elk are being produced consistantly.

Whitetail seems not to be effected by high harvest rates except in certain areas. Mule deer have been greatly effected by high harvest rates and the numbers have gone down because of habitat and harvest rates. Because of this areas have been set aside for limited harvest of Mule deer in most states. Most Fish and Wildlife Agencies in the U.S. have gone from a maximum sustained harvest to what habitat will sustain. These means increasing Male/female ratio and the female/young ratio. We have had a greater harvest of whitetail does and cow elk today then ever in recent history. It you look at the record books, there has been a tremendous increase in entries in the last few years. This has been a boon to the hunter nation wide. Today we have more liberal hunting seasons nationwide for whitetail.

The re-introduction of elk, Bighorn Sheep, Mt. Goat and other species back into their native Habitat. You have elk and other species in places you have not seen since 1900. You are seeing states setting aside certain areas for trohy deer and elk.

I am sure because of the demand for 100 lb tusks in elephants there are fewer and fewer of these animals. Some of this is due to poaching, comercial harvsting in the past but today it is hunting. I have read some where there are whole herds elephants that have nothing but tuskless bulls.

The antelope species of Africa it is a different story. It is money and strict game management by private individuals and some cases the government we continue to have exceptional horned species.

Some Governments of Africa have restricted the numbers of certain species that can be harvested or in some cases completely banned the taking of certain species until they can recover to huntible, sustainable population. This includes anything from elephants,lions, leopards to Bongo to the little blue Duiker.

So, I what I am trying to say here is. The report is true as far as it goes but is also very misleading. We would not have the numbers or quality of wildlife today if it was not for the hunters and the wildlife managers (private and government) we have today.

I am sorry I was little long winded in this reply but it is this type of reports that can hurt us hunters by being so short sighted and incomplete.

We as hunters, sportsman and wildlife managers realized this a long time ago. We did not need a study to tell us this.

Interesting differences in the two responses from Brooks and SGraves!
Peter.

Its imminently plausible!

Brooks has a good point. However Brooks I used to believe that sport fishing could never match commercial takeoff in some cases until I found it does in two examples I was explained. I was interviewing a biologist at Saskatchewan Environment about native dislike of sport fisheries in the north-west of that province. I was incredulous to their claims that sport anglers hurt stocks that they target commercially.

I didn't think the anglers caught enough, but according to this biologist they catch way more than we think due to the dispersed and steady nature of their catches. He said the same is true with salmon fishing off the BC coast, in certain areas sport anglers exceed commercial take off.

I can't verify those claims without in depth research but nonetheless it was interesting to hear.

Its completely plausible that populations under even moderate hunting pressure could change behaviour which may lead to slight physiological changes that select for body size, horn size etc that favours different reproductive, escape, feeding or new habitat changes.

Oh yes, they forgot about 'intelligent design'

quote:

Regulations meant to protect the young may in fact be helping drive this unnatural process, Darimont said.

"Hunters are instructed not to take smaller animals or those with smaller horns. This is counter to patterns of natural predation, and now we're seeing the consequences of this management," he said.

That is the PC part of the article.

Brooks and kayaker both have good points, and I don't think we have any disagreement.

In the case of elephants, where poachers nearly eliminated tusked animals in areas, the abundance of tuskless is no surprise.
If large game animals, allowed to live to the peak of their physical abilities, were getting smaller in the past two decades, it would be evident to many hunters. The exact opposite seems to be the case to me.
Over-harvesting of adults will obviously lead to "smaller' animals, but simply because those remaining are younger. Most State Game agencies that were having problems with lack of big bucks realized that the solution was to not shoot the younger ones and rules regarding antler size were instituted. If you want to see what really works on game management to increase antler size, look at the management efforts of the successful game ranches.

quote:

They studied changes in the size of fish, limpets, snails, bighorn sheep and caribou, as well as two plants - the Himalayan snow lotus and American ginseng.

The only two species here (other than possibly unspcified "fish") that would fall into the trophy category are bighorns and caribou. In terms of bighorns, I seriously doubt that sufficient baseline data exists to make any dependable statement. As to caribou, such generalizations would seem absurd on their face in that huge numbers of caribou live and die without ever being exposed to a trophy hunter.

I don't question that predation by man (or other animals) can impact populations and characteristics of prey of animals. After all, it was predation that gave the zebra its stripes, and if predation can do something as spectacular as that, then it can do other things such as affect body size and reproductive age.

If the problem from human predation is that it tends to take the largest and healthiest individuals of a population, then it is also human demand for the largest and healthiest that ensures that predation will be regulated to sustainably produce large and healthy individuals.

Were human predation unregulated -- and if a study like this relies on historic data which includes centuries or decades of unregulated human predation such as the bison slaughter of the 1870's -- then there might be some validity to its conclusions. However, to assume that such historic data is still valid for the last half-century of highly regulated sport hunting would lead to inaccurate conclusions about the impact of regulated sport hunting.

For one I would like to scrutinize their study and sample sizes and methods. A look at the record book for many species belies their findings. The other fact is that many studies have been done that show the size and vitality of animals are much more
related to habitat, particularly food, than genetics. I question also that this natural selection of sheep occurs in 5 or 6 generations, during which the study takes place. That is like expecting humans to be selected for a sixth finger on each hand since we have been
using computers so much for the last 50 years. I would be studying changes in habitat in these species and the changes over the last several decades even pollutants might be another consideration. That is why one should look at the controls used to come to the conclusions arrived at.
Sounds more like a result looking for a study. Just my thoughts.

Jim

For over a century, in my region, East of France, as in Germany, our first priority is to shoot all the feeble and misfit animals.That keeps diseases at bay and prevents them from passing their poor genes.
Unfortunately, it results that our populations aren’t at all better than in other regions of France.

Concerning the red stag population : we are allowed to shoot only spikes and stags older than 8 years. It’s thoroughly applied and the administration fussily checks it .
It results that our stags are less nice than in other regions that are shooting stags randomly.

The guy that "conducted" this study is a first year PHD from UC Santa Cruz, a dedicated anti-hunter and greenie that has spent most of his time trying to justify the tremendous increase in the number of wolves in the West. Go on line and check out his CV. The study is anti-hunting propaganda in the "guise" of research. If you read the article yesterday that was posted on line on Fox News, Darimont basically said that "trophy hunting" is primarily responsible for diminution in size of several species and will lead to the extinction of many, as well as the increase in tuskless elephant. Like most "studies" of this type, there is no distinction made between hunting and poaching. They also cite an article that says that hunting is responsible for the decline in the overall size of Brown Bears in Alaska, even though most outfitters and others will say the population has never been bigger or better. The inclusion of big horn sheep in the study is laughable to me. The number of large mature rams taken by hunters (most well past prime breeding) is a small fraction of the number of sheep killed by predators throughout their range. I was so mad when I finished reading this, I basically wanted to throw up.

EB has made some valid points.

It is true that Bear populations do increase when you kill older mature bears and there is good reason for this. Your very old bears will kill the young cubs as quick as they can so so the female will come back into heat. So, when you eliminate these older class bears, you do increase your numbers. So, it does stand to reason, the numbers of 20 year old plus bears will be fewer due to hunter kill. Brown (Grizzly) Bears have no natural preditors except man. Why has Alaska restricted the kill of Brown bears in certain areas. Is it over harvest of these older class bears. I do not know, I leave that up to the biologist's of Alaska. Do we still get these big Brown Bear, yes we do.

I did a quick check of B&C record book and found in the top 50 all were killed prior to 1960 except for 1. There are fewer and fewer of these older class bears being killed every year. Does that mean his research is correct no it does not. It just means we are not letting these bears get old and big enough.

As for Big Horn Sheep it'a natural predator is the Mt. Lion. For Dall sheep, I suspect it will be both bears and wolves. Yet, the numbers of Dall Sheep in Alaska, Yukon, NWT and British Columbia seem to be doing alright. I know there was a period of time in British Columbia there was an all out effort to kil wolves to reduce the predation of wolves on sheep. The reason was the survival rate of the young sheep was down Thus wolves were in direct competion with the outfitters and hunters. I do not believe they are doing this anymore but I could be wrong.

I would like to know where EB gets his information that it is predators are the main killers of older class Sheep. The sheep carcasses found near feeding stations in Washington would not substanate this. The sheep had radio collars or were ear tagged. The older rams were either shot by hunters or just died of old age. Preditors actually targeted the young. In the lower 48 in modern times, disease was the primary cause that reduced or elimated sheep populations. This has been proven time and time again. New introductions of sheep in the lower 48 seem to do quite well when first introduced in a area. Populations grow, Rams grow exceptional heads, then after many years there is a crash. When this happens, it is discovered domestic sheep or goats are usually the cause. In SE Washington in the 90's they had a large sheep population that was spreading into Oregon and Idaho. It produced many 180 to 200 class rams. They had permits by drawings in the area and the chance of taken a Boone and Crockett Ram was 100 percent. There were Mt. Lions and bears in the area but they had no effect on the population. It was still growing. Hunting had no effect either as it was being closely monitored. A true success story. I was one of those people every year put in for one of those permits. Then all of sudden the sheep contracted pneumonia. The state of Washington went in and captured as many of the sheep as they could to try and save them but it was too late. The cause, some local thought it would be nice to turn some domestic goats and sheep loose in the area. This same thing has happened in Oregon, Mountana and Colorado. I do not know about the other western states but I suspect it has happened. When you have introduction of domestic sheep into the wild where there is wild sheep, you will have die off of wild sheep. Domestic sheep are carriers of diseases that kill wild sheep. That has been proven time and time again.

As I said the person who did this study did not go far enough. This guy could be anti-hunter for all I know. But, it is up to us to disprove what he says. Poaching unfortunately in most studies does not enter into studies. I am sure there is many flaws in his studies.

I have hunted all my life and I try not to go off half cocked. Sometimes I screw up and make mistakes and I will admit that. If I have made a mistake in my assumptions above I do apologize in advance.

I try use my life experiences, my training and the expertise of others to disprove these false studies. I am not trying to get into p*******g match with anybody.

I am just giving my propective of the what I see here in this short sighted Thesis. Like most people this PHd canidate was trying to prove his thesis by leaving out important data.


Time to get off my soap box.