The study found that wolves living on the landscape with cattle have no effect on herd weight, but once a ranch has a confirmed wolf kill, average calf weight decreases relative to if that ranch had not experienced a wolf depredation.
“Ranchers have been saying for years that wolves cause weight loss in cattle, but nobody ever had done any research on the topic,” said Derek Kellenberg, a co-author on the study and UM associate professor and chair of the Department of Economics.
Kellenberg worked with UM Associate Professor Mark Hebblewhite from the Wildlife Biology Program and graduate students Joseph Ramler and Carolyn Sime. The Montana Department of Fish, Wildlife and Parks also cooperated on the study, which analyzed data from ranches in western Montana, including 15 years of records on ranch husbandry, satellite-generated climatological data, spatial data on wolf pack locations and confirmed depredations on 18 ranches.
The study quantifies the economic impact of weight loss after a confirmed wolf kill for an average ranch consisting of 264 head of calves. It finds that a decrease of 22 pounds in the average weight of calves across the herd implies a $6,679 loss at sale for an affected ranch.
“When you compare that to the direct reimbursement of the cow that was killed – about $900 on average – these indirect costs are about seven-and-a-half times the direct cost of depredation,” Kellenberg said.
The study notes that while the economic impact of lower herd weights caused by wolf depredation is not insignificant to ranchers, other ranch-specific husbandry practices and climatological and environmental variables such as annual precipitation, average temperature and snowfall explain a much larger proportion of variance in calf weight over the years than do wolf affects. In fact, these other factors explain the vast majority of the accounted-for variation in annual calf weights.
The study started as a senior thesis by then-undergraduate student Ramler, collecting data from public cattle auction records. When he decided to pursue a master’s in economics from UM, the group started collecting and analyzing data from a survey of individual western Montana ranchers.
Kellenberg hopes the study will help inform policymakers and ranchers as they work on issues related to wolf management.
“This study helps quantify some of the indirect costs that have not previously been accounted for,” he said.
The study was published Jan. 10 in the American Journal of Agricultural Economics and is titled “Crying Wolf? A Spatial Analysis of Wolf Location and Depredations on Calf Weight.” For more information visit http://www.cas.umt.edu/econ/, call Kellenberg at 406-243-5612 or email email@example.com
Derek Kellenberg | EurekAlert!
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy