Navigation Links
Animal trapping records reveal strong wolf effect across North America
Date:6/15/2014

CORVALLIS, Ore. Scientists have used coyote and red fox fur trapping records across North America to document how the presence of wolves influences the balance of smaller predators further down the food chain.

From Alaska and Yukon to Nova Scotia and Maine, the researchers have demonstrated that a "wolf effect" exists, favoring red foxes where wolves are present and coyotes where wolves are absent.

This effect requires that enough wolves be present to suppress coyotes over a wide area. Fur trapping records from Saskatchewan and Manitoba reveal that where wolves are absent in the southern agricultural regions of each province, coyotes outnumber foxes on average by 3-to-1. However, where wolves are abundant in the north, the balance swings dramatically in favor of foxes on average by 4-to-1 and at an extreme of 500-to-1 at one site.

In between is a 200-kilometer (124-mile) transition zone where too few wolves are present to tip the balance between coyotes and foxes.

The results of the study by Thomas Newsome and William Ripple in the Oregon State University Department of Forest Ecosystems and Society were published today in the Journal of Animal Ecology by the British Ecological Society.

"As wolves were extirpated across the southern half of North America, coyotes dramatically expanded their range," said Newsome, a post-doctoral researcher at Oregon State. "They were historically located in the middle and western United States, but they dispersed all the way to Alaska in the early 1900s and to New Brunswick and Maine by the 1970s."

"So essentially coyotes have been dispersing into wolf and red-fox range in the north but also into areas where wolves are absent but red fox are present in the East," Newsome added.

Newsome came to the United States on a Fulbright scholarship from Australia where he earned a Ph.D. from the University of Sydney and specialized in the study of dingoes that continent's top predator. There's a debate among Australians, he said, about the potential role of dingoes in suppressing introduced pests that have already decimated wildlife there.

"Over the last 200 years, Australia has had the highest extinction rate in the world," Newsome said. "The debate is about whether the dingo can provide positive ecological benefits. Where dingoes have been removed, the impacts of introduced red foxes and feral cats have been quite severe on native fauna."

Dingoes are managed as a pest in New South Wales, the country's most populous state. To reduce dingo predation in the livestock industry, Australia also maintains the world's longest fence, which runs for 5,500 kilometers (3,400 miles) in an attempt to exclude dingoes from almost a quarter of the continent.

In North America, the effect of wolves on coyotes and red foxes provides a natural case study that can be instructive for Australians. "Australians can learn a lot from how wolves are managed in North America, and Americans can learn from the ecological role of the dingo," Newsome said.

As coyotes have expanded in North America, they have become a major cause of concern for the livestock industry. In the United States in 2004, researchers estimated annual losses due to coyote predation on sheep and cattle at $40 million. To reduce those damages, the Wildlife Service of the U.S. Department of Agriculture has a program to reduce coyote numbers, an effort that has drawn criticism from conservation groups.

In reviewing the fur trapping data from two U.S. and six Canadian jurisdictions, Newsome and Ripple eliminated potential sources of bias such as records from fur farms that raise foxes. The fur prices of coyotes and red foxes are also strongly correlated, and the two species occupy much of the same types of habitat, so they are equally likely to be targeted and caught in hunters' traps.

"This study gives us a whole other avenue to understand the ecological effects of wolves on landscapes and animal communities," said Ripple. He has studied the influence of carnivores on their prey such as deer and elk and on vegetation from aspen trees to willows. He and his colleagues have shown that the removal of top predators can cause dramatic shifts within ecosystems.

Wolves are naturally recolonizing many areas of the United States following their reintroduction into Yellowstone National Park and surrounding areas in 1995. Scientists are studying wolf interactions with other species, and in particular, there is interest in determining whether recolonizing wolves will suppress coyote populations and have cascading effects on red foxes and other species.


'/>"/>

Contact: William Ripple
bill.ripple@oregonstate.edu
541-737-3056
Oregon State University
Source:Eurekalert

Related biology news :

1. Listening helps scientists track bats without exposing the animals to disease
2. Gene therapy extends survival in an animal model of spinal muscular atrophy
3. Domesticated animals provide vital link to emergence of new diseases
4. Comet theory false; doesnt explain Ice Age cold snap, Clovis changes, animal extinction
5. Humans and companion animals harbor the same types of MRSA infections
6. First-ever study describes deep-sea animal communities around a sunken shipping container
7. Animal hoarding, a lesser-known problem for public health and welfare
8. Initial research: Mangos effects on ulcerative colitis & bone parameters in animal models
9. 7.0T NMR assesses changes in hippocampal neurons in animal models of Alzheimers disease
10. Animals with bigger brains, broader diets have better self control
11. Best practices in communication for the animal world
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/10/2016)... 10, 2016 --> ... report "Identity and Access Management Market by Component (Provisioning, ... Governance), by Organization Size, by Deployment, by Vertical, and ... MarketsandMarkets, The market is estimated to grow from USD ... 2020, at a Compound Annual Growth Rate (CAGR) of ...
(Date:3/9/2016)... 9, 2016 This BCC Research report provides ... the RNA Sequencing (RNA Seq) market for the years ... tools and reagents, data analysis, and services. ... the RNA-Sequencing market such as RNA-Sequencing tools and reagents, ... factors affecting each segment and forecast their market growth, ...
(Date:3/9/2016)... March 9, 2016  Crossmatch ® , a ... solutions, today announced the addition of smart features ... multi-factor authentication platform. New contextual and application-specific ... step-up security where it,s needed most — while ... DC . --> Washington, ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... ... 2016 , ... Proove Biosciences, Inc ., the commercial ... of the Proove Health Foundation . The Foundation is a non-profit organization ... of personalized medicine for tackling the nation’s most-pressing healthcare epidemics. As part of ...
(Date:4/29/2016)... ... ... Intelligent Implant Systems announced today that the two-level components for the Revolution™ ... States. These components expand the capabilities of the system and allow Revolution™ to ... of 2015, the company has seen significant sales growth in 1Q 2016, and the ...
(Date:4/28/2016)... ... April 28, 2016 , ... Next week on May ... its first-in-class technologies for tissue stem cell counting and expansion to gene-editing scientists ... Reprogramming & CRISPR-based Genome Engineering in Burlington, Massachusetts. , The attention of most ...
(Date:4/27/2016)... ... ... The Pittcon Organizing Committee is pleased to announce that Charles “Chuck” Gardner was ... since 1987. Since then, he has served in a number of key leadership positions ... the program and exposition committees. In his professional career, Dr. Gardner is the director ...
Breaking Biology Technology: