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 firstname.lastname@example.org
Derek Kellenberg | EurekAlert!
Sequencing of barley genome achieves new milestone
26.08.2015 | University of California - Riverside
Entomologists sniff out new stink bug to help soybean farmers control damage
25.08.2015 | Texas A&M AgriLife Communications
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.
These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...
Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.
For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...
It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.
Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
28.08.2015 | Physics and Astronomy
28.08.2015 | Health and Medicine
28.08.2015 | Life Sciences