Loss of Apex Predators Devastating Ecosytems

running wolf

This is what conservationists have been saying all along. Killing off top predators, like the wolf, have a negative effect on the environment. They are a vital part of our ecosystem, contributing in ways we are only beginning to understand.

This cautionary tale wildlife managers around the world should pay attention to!!

“We reached the old wolf in time to watch the fierce green fire dying in her eyes… There was something new to me in those eyes– something known only to her and the mountains. I was young then, and full of trigger-itch. I thought that because fewer wolves meant more deer that no wolves would mean hunter’s paradise, but after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.”
~ Aldo Leopold

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Loss of top predators causing surge in smaller predators, ecosystem collapse

Science Centric | 2 October 2009 12:43 GMT

The catastrophic decline around the world of ‘apex’ predators such as wolves, cougars, lions or sharks has led to a huge increase in smaller ‘mesopredators’ that are causing major economic and ecological disruptions, a new study concludes.

The findings, published today in the journal Bioscience, found that in North America all of the largest terrestrial predators have been in decline during the past 200 years while the ranges of 60 percent of mesopredators have expanded. The problem is global, growing and severe, scientists say, with few solutions in sight.

An example: in parts of Sub-Saharan Africa, lion and leopard populations have been decimated, allowing a surge in the ‘mesopredator’ population next down the line, baboons. In some cases children are now being kept home from school to guard family gardens from brazen packs of crop-raiding baboons.

‘This issue is very complex, and a lot of the consequences are not known,’ said William Ripple, a professor of forest ecosystems and society at Oregon State University. ‘But there’s evidence that the explosion of mesopredator populations is very severe and has both ecological and economic repercussions.’

In case after case around the world, the researchers said, primary predators such as wolves, lions or sharks have been dramatically reduced if not eliminated, usually on purpose and sometimes by forces such as habitat disruption, hunting or fishing. Many times this has been viewed positively by humans, fearful of personal attack, loss of livestock or other concerns. But the new picture that’s emerging is a range of problems, including ecosystem and economic disruption that may dwarf any problems presented by the original primary predators.

‘I’ve done a lot of work on wildlife in Africa, and people everywhere are asking some of the same questions, what do we do?’ said Clinton Epps, an assistant professor at OSU who is studying the interactions between humans and wildlife. ‘Most important to understand is that these issues are complex, the issue is not as simple as getting rid of wolves or lions and thinking you’ve solved some problem. We have to be more careful about taking what appears to be the easy solution.’

The elimination of wolves is often favoured by ranchers, for instance, who fear attacks on their livestock. However, that has led to a huge surge in the number of coyotes, a ‘mesopredator’ once kept in check by the wolves. The coyotes attack pronghorn antelope and domestic sheep, and attempts to control them have been hugely expensive, costing hundreds of millions of dollars.

‘The economic impacts of mesopredators should be expected to exceed those of apex predators in any scenario in which mesopredators contribute to the same or to new conflict with humans,’ the researchers wrote in their report. ‘Mesopredators occur at higher densities than apex predators and exhibit greater resiliency to control efforts.’

The problems are not confined to terrestrial ecosystems. Sharks, for instance, are in serious decline due to overfishing. In some places that has led to an explosion in the populations of rays, which in turn caused the collapse of a bay scallop fishery and both ecological an economic losses.

Among the findings of the study:

Primary or apex predators can actually benefit prey populations by suppressing smaller predators, and failure to consider this mechanism has triggered collapses of entire ecosystems.

Cascading negative effects of surging mesopredator populations have been documented for birds, sea turtles, lizards, rodents, marsupials, rabbits, fish, scallops, insects and ungulates.

The economic cost of controlling mesopredators may be very high, and sometimes could be accomplished more effectively at less cost by returning apex predators to the ecosystem.

Human intervention cannot easily replace the role of apex predators, in part because the constant fear of predation alters not only populations but behaviour of mesopredators.

Large predators are usually carnivores, but mesopredators are often omnivores and can cause significant plant and crop damage.

The effects of exploding mesopredator populations can be found in oceans, rivers, forests and grasslands around the world.

Reversing and preventing mesopredator release is becoming increasingly difficult and expensive as the world’s top predators continue to edge toward obliteration.

‘These problems resist simple solutions,’ Ripple said. ‘I’ve read that when Gen. George Armstrong Custer came into the Black Hills in 1874, he noticed a scarcity of coyotes and the abundance of wolves. Now the wolves are gone in many places and coyotes are killing thousands of sheep all over the West.’

‘We are just barely beginning to appreciate the impact of losing our top predators,’ he said.

At OSU, Ripple and colleague Robert Beschta have done extensive research and multiple publications on the effect that loss of predators such as wolves and cougars have on ecosystem disruption, not only by allowing increased numbers of grazing animals such as deer and elk, but also losing the fear of predation that changes the behaviour of these animals. They have documented ecosystem recovery in Yellowstone National Park after wolves were reintroduced there.

http://www.sciencecentric.com/news/article.php?q=09100236-loss-top-predators-causing-surge-smaller-predators-ecosystem-collapse

photo credited to :  http://www.firstpeople.us/pictures/wolves/1024×768/f-wolves99-11-s-1024×768.html

Categories posted in: biodiversity,  gray wolf   Tags: endangered species act, gray wolf

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Published in: on October 2, 2009 at 1:16 pm  Comments (4)  
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4 CommentsLeave a comment

  1. I know! The wolf is an EXTRAORDINARY creature!!! I’m all for them!!! Some people think that they are just vicious killers. Well that is SOOOOOOO not true!!!! They are LIVING THINGS that are just fighting to survive. I despise those that hunt wolves and kill them for no good reason!!!!!!!!!!!! 😡

    Like

    • Hi Ayana,
      I’m with you all the way. The wolf hunts are cruel and unnecessary. How anyone can make a decision to go out and shoot a wolf is beyond my comprehension but I don’t really understand killing elk or deer either. Most hunters are not sustenance hunters because it takes money to hunt. The people that need the meat can’t afford all the licensing fees, equipment, guns, ammunition, etc. So IMO people hunt because they like to kill things. The meat is secondary.

      I just want the wolf hunts to stop but we’re powerless until Judge Molloy rules on the case. I don’t believe Salazar is going to change his mind on this and give wolves their ESA protections back without a fight.

      We’re having a meditation on Sunday for the wolves, hope you join in. You can do it from anywhere you are. I have the info posted on my home page.

      For the wild ones,
      Nabeki

      Like

  2. Why anyone would hunt these magnificent creatures is totally beyond me! I believe that these animals should be celebrated for their teamwork, strentgh, gracefullness and more. we NEED to take a stand and raise awareness about the wolf population and about hunting wolves!

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    • Hi,
      I don’t understand the thinking of people that would kill wolves for pleasure either. There is so much to celebrate about the wolf, as you said.

      I do think the wolf hunts have been an impetus to get people motivated to do something. I don’t believe people outside the Norhern Rocikies realized the fierce battle that’s been raging here, really since wolves were reintroduced. If the hunts have helped to rally people to their diefense then the wolves haven’t died in vain. Everything rests with Judge Molloy.

      Like


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