By Hanneke Brooymans
EDMONTON - Wolves are eating more cattle in southwestern Alberta than previously known, according to researchers from the University of Alberta.
Andrea Morehouse and Mark Boyce tackled the research based on a request from the province's fish and wildlife division. There had not been any wolf diet work done in southwestern Alberta and there was a growing concern among cattle producers, said Morehouse, who is now a PhD student at the University of Alberta. Since 2000, compensation paid to livestock producers because of wolf predation on cattle rose from $45,321 to $110,046, according to their research paper, which was published online in Frontiers in Ecology and Environment on March 24.
"Southwestern Alberta is a unique part of the province in that the interface between the mountains and the prairies is very sharp and there's a high degree of overlap between where livestock are grazing and where wildlife, including carnivores, have home ranges and territories," Morehouse said in an interview. "This overlap means there's probably a little more potential for conflict here than elsewhere in the province, so that's why we focused down there."
Wolf diet research is usually done by analyzing scat. But wolves also scavenge, so what's in scat isn't necessarily what they have killed. Morehouse also used global positioning system technology from June 2008 through October 2009 to find where clusters of wolves had been to help figure out what they were eating and whether the wolves had killed the prey themselves. The technology was particularly useful in the summer.
"Producers in southwestern Alberta put their cows in the forest reserve in roughly May and pull them out in roughly October, and they're often a few head short," Morehouse said. "So they're missing a few cattle and they've long suspected that wolves are accounting for the ones that are missing. But they haven't had evidence to support that claim. "The GPS cluster method allowed us to locate some of those cattle that would probably have otherwise been classified as missing because although there are people out there riding the area, it's very hard to find a kill site in the summer. Wolves consume their prey very rapidly and they spread the bones all over the place. So without something to get you in the right spot it's very hard in a forested area to find something."
During the course of their study, they found the remains of 50 cattle at wolf kill sites from three packs. In response to the increasing cattle predations during that time period, the government did control packs in this area, Morehouse said. They removed the Bob Creek pack of four wolves and the Crowsnest pack of two.
Dave Ealey, a spokesman for Alberta Sustainable Resource Development, said they do manage wolf packs that target livestock, but because wolf populations are on the rise those packs are often quickly replaced.
Morehouse also noticed that during the non-grazing season the wolves were scavenging at boneyards where ranchers dispose of their dead stock.Before bovine spongiform encephalopathy, rendering plants would pick up the dead animals free of charge. But now that certain tissues are prohibited from use in livestock feed, pet food and fertilizer, the companies charge for pick up. It's too expensive for many producers, so they would pile up the dead animals in the boneyard instead."Boneyards represented an important food source for wolves during winter, and they often made repeated visits to these locations," Morehouse and Boyce wrote. "This is especially problematic because boneyards are required to be a minimum of only 400 metres from livestock facilities and residences. This brings carnivores into close contact with other stock-growing activities (e.g. calving), which could result in further conflict between wildlife and ranchers." Morehouse said a potential solution would be to use bear-proof metal storage bins in place of boneyards, to reduce scavenging and prevent carnivores from becoming accustomed to feeding on livestock.
Ealey said over the last two years the government has been placing dead-stock storage bins in the Cardston and Twin Butte area, so bears and wolves aren't attracted to the area. The bins are like regional waste management bins, offering a more cost-effective way to have dead cattle hauled away. It has had the desired effect on bears, but no followup research has been done to see if it's working on wolves.
The study received funding and logistical support from a wide variety of sources including, among others, the provincial government, the Alberta Beef Producers, the Alberta Conservation Association, Parks Canada and Shell. The cattle industry employee who was involved in the project could not be reached for comment Friday.
"Southwestern Alberta is a unique part of the province in that the interface between the mountains and the prairies is very sharp and there's a high degree of overlap between where livestock are grazing and where wildlife, including carnivores, have home ranges and territories," Morehouse said in an interview. "This overlap means there's probably a little more potential for conflict here than elsewhere in the province, so that's why we focused down there."
Wolf diet research is usually done by analyzing scat. But wolves also scavenge, so what's in scat isn't necessarily what they have killed. Morehouse also used global positioning system technology from June 2008 through October 2009 to find where clusters of wolves had been to help figure out what they were eating and whether the wolves had killed the prey themselves. The technology was particularly useful in the summer.
"Producers in southwestern Alberta put their cows in the forest reserve in roughly May and pull them out in roughly October, and they're often a few head short," Morehouse said. "So they're missing a few cattle and they've long suspected that wolves are accounting for the ones that are missing. But they haven't had evidence to support that claim. "The GPS cluster method allowed us to locate some of those cattle that would probably have otherwise been classified as missing because although there are people out there riding the area, it's very hard to find a kill site in the summer. Wolves consume their prey very rapidly and they spread the bones all over the place. So without something to get you in the right spot it's very hard in a forested area to find something."
During the course of their study, they found the remains of 50 cattle at wolf kill sites from three packs. In response to the increasing cattle predations during that time period, the government did control packs in this area, Morehouse said. They removed the Bob Creek pack of four wolves and the Crowsnest pack of two.
Dave Ealey, a spokesman for Alberta Sustainable Resource Development, said they do manage wolf packs that target livestock, but because wolf populations are on the rise those packs are often quickly replaced.
Morehouse also noticed that during the non-grazing season the wolves were scavenging at boneyards where ranchers dispose of their dead stock.Before bovine spongiform encephalopathy, rendering plants would pick up the dead animals free of charge. But now that certain tissues are prohibited from use in livestock feed, pet food and fertilizer, the companies charge for pick up. It's too expensive for many producers, so they would pile up the dead animals in the boneyard instead."Boneyards represented an important food source for wolves during winter, and they often made repeated visits to these locations," Morehouse and Boyce wrote. "This is especially problematic because boneyards are required to be a minimum of only 400 metres from livestock facilities and residences. This brings carnivores into close contact with other stock-growing activities (e.g. calving), which could result in further conflict between wildlife and ranchers." Morehouse said a potential solution would be to use bear-proof metal storage bins in place of boneyards, to reduce scavenging and prevent carnivores from becoming accustomed to feeding on livestock.
Ealey said over the last two years the government has been placing dead-stock storage bins in the Cardston and Twin Butte area, so bears and wolves aren't attracted to the area. The bins are like regional waste management bins, offering a more cost-effective way to have dead cattle hauled away. It has had the desired effect on bears, but no followup research has been done to see if it's working on wolves.
The study received funding and logistical support from a wide variety of sources including, among others, the provincial government, the Alberta Beef Producers, the Alberta Conservation Association, Parks Canada and Shell. The cattle industry employee who was involved in the project could not be reached for comment Friday.
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