A biological scientist at the University of Alberta, Boyce analyzed 774 wolf-elk kill sites and concluded that spatial patterns of predation between wolves and elk are more strongly influenced by landscape features than by wolf distribution.
"We found that even though wolf and elk populations overlapped in many areas of our study, the kill sites did not correlate with the areas of overlap as much as they were consistent with certain landscape features, such as proximity to roads," Boyce said.
The research results were published recently in the academic journal Ecology Letters.
Boyce and his colleagues studied the wolf-elk interactions over a period of 10 consecutive winters in a northern range of the Yellowstone National Park in the U.S.
The area has been of special interest to researchers since 14 wolves from the Canadian Rockies were introduced to the park in 1995. Wolves had been extirpated from Yellowstone in the 1930s, and some people speculated the re-introduced wolves would doom the park's elk population. However, while the number of wolves on Yellowstone's northern range has since grown to 84, the number of elk has not declined appreciably.
"We've found that the availability of refuge areas for elk, and their ease of accessing them, should buffer the elk population in the park from extreme levels of predation," Boyce said.
Boyce added that wolves are inefficient predators, with low rates of hunting success—usually around 20 per cent—which is due, in part, to the large size and defensive capabilities of elk, their main prey. Prime-age adult elk are largely invulnerable to predation from wolves, which are highly selective and target the young, old or weak.
"Our findings suggest that landscape features may often 'tip the balance' in predator-prey outcomes, thus influencing post-encounter outcomes," Boyce said.
Boyce and colleagues noted that "browse communites"—foraging areas in open, flat landscape near roads or rivers (which can cut off escape routes)—offer the greatest risk of wolf predation for elk. Also, deep snowy areas, which are much harder for the heavy, hoof-legged elk to move through than the lighter, wide-pawed wolves, are also dangerous.
The great challenge for the elk, however, is that the risky foraging areas provide sustenance during the critical winter months, when the elk experience shrinking fat reserves.
"Our study makes clear that elk in winter face a clear trade-off between forage quality and predation risk. How elk perceive and manage the trade-off between food and safety will ultimately determine if they will survive," Boyce said.
Ryan Smith | EurekAlert!
Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
19.07.2017 | Event News
12.07.2017 | Event News
12.07.2017 | Event News
20.07.2017 | Information Technology
20.07.2017 | Materials Sciences
20.07.2017 | Physics and Astronomy