Friday, June 15, 2012

Cougars are re-populating their historical range



American mountain lions, or cougars, are re-emerging in areas of the United States, reversing 100 years of decline. The evidence, published in The Journal of Wildlife Management, raises new conservation questions, such as how humans can live alongside the returning predators.

"The cougar population declined dramatically from 1900, due to both hunting, and a lack of prey, leaving the remaining population isolated to the American west," said Michelle LaRue from the University of Minnesota. "Here we present the hard evidence that the western population has spread, with cougar populations re-establishing across the Midwest."

Three main cougar populations exist in the Midwest centered around The Black Hills in South Dakota, however, cougars are venturing far outside of this range. One male cougar from the Black Hills was found to have traveled 2,900 kilometers through Minnesota, Wisconsin and New York, before ending up in Connecticut.

"While the distance the Connecticut cougar traveled was rare, we found that cougars are roaming long distances and are moving back into portions of their historical range across the Midwest ", said LaRue. "Our study took in over 3,200,000 Km_ of territory, confirming the presence of Cougars from Texas, Arkansas and Nebraska, to the Canadian provinces of Ontario and Manitoba."

Working alongside scientists from Southern Illinois University Carbondale and The Cougar Network, LaRue and Principal Investigator Dr. Clay Nielsen analyzed cougar sightings which have been reported since the 1990's to characterize confirmed sightings over time, assess habitat suitability and confirm where cougar populations are being re-established.

Aside from confirmed sightings, the team's evidence included carcasses, tracks, photos, video, DNA evidence and cases of attacks on livestock across 14 states and provinces of North America. Only sightings which were verified by wildlife professionals were included, while sightings of animals known to be released from captivity were excluded to ensure only natural repopulation was analyzed.

The results reveal 178 cougar confirmations in the Midwest with the number of confirmations steadily increasing between 1990 and 2008. Approximately 62% of confirmed sightings took place within 20km of habitat that would be considered suitable for cougar populations.

When cougar carcasses were recovered 76% were found to be male. As the Connecticut example shows, males are capable of traveling long distances and this finding suggests males are leading a stepping-stone dispersal of the cougar population.

"This evidence helps to confirm that cougars are re-colonizing their historical range and reveals that sightings have increased over the past two decades," concluded LaRue. "The question now is how the public will respond after living without large carnivores for a century. We believe public awareness campaigns and conservation strategies are required across these states, such as the Mountain Lion response plans already in place in Nebraska and Missouri."

Saturday, April 14, 2012

Loss of Predators in Northern Hemisphere Affecting Ecosystem Health

A survey on the loss in the Northern Hemisphere of large predators, particularly wolves, concludes that current populations of moose, deer, and other large herbivores far exceed their historic levels and are contributing to disrupted ecosystems.

The research, published recently by scientists from Oregon State University, examined 42 studies done over the past 50 years.

It found that the loss of major predators in forest ecosystems has allowed game animal populations to greatly increase, crippling the growth of young trees and reducing biodiversity. This also contributes to deforestation and results in less carbon sequestration, a potential concern with climate change.

"These issues do not just affect the United States and a few national parks," said William Ripple, an OSU professor of forestry and lead author of the study. "The data from Canada, Alaska, the Yukon, Northern Europe and Asia are all showing similar results. There's consistent evidence that large predators help keep populations of large herbivores in check, with positive effects on ecosystem health."

Densities of large mammalian herbivores were six times greater in areas without wolves, compared to those in which wolves were present, the researchers concluded. They also found that combinations of predators, such as wolves and bears, can create an important synergy for moderating the size of large herbivore populations.

"Wolves can provide food that bears scavenge, helping to maintain a healthy bear population," said Robert Beschta, a professor emeritus at OSU and co-author of the study. "The bears then often prey on young moose, deer or elk -- in Yellowstone more young elk calves are killed by bears than by wolves, coyotes and cougars combined."

In Europe, the coexistence of wolves with lynx also resulted in lower deer densities than when wolves existed alone.

In recent years, OSU researchers have helped lead efforts to understand how major predators help to reduce herbivore population levels, improve ecosystem function and even change how herbivores behave when they feel threatened by predation -- an important aspect they call the "ecology of fear."

"In systems where large predators remain, they appear to have a major role in sustaining the diversity and productivity of native plant communities, thus maintaining healthy ecosystems," said Beschta. "When the role of major predators is more fully appreciated, it may allow managers to reconsider some of their assumptions about the management of wildlife."

In Idaho and Montana, hundreds of wolves are now being killed in an attempt to reduce ranching conflicts and increase game herd levels.

The new analysis makes clear that the potential beneficial ecosystem effects of large predators is far more pervasive, over much larger areas, than has often been appreciated.

It points out how large predators can help maintain native plant communities by keeping large herbivore densities in check, allow small trees to survive and grow, reduce stream bank erosion, and contribute to the health of forests, streams, fisheries and other wildlife.

It also concludes that human hunting, due to its limited duration and impact, is not effective in preventing hyper-abundant densities of large herbivores. This is partly "because hunting by humans is often not functionally equivalent to predation by large, wide-ranging carnivores such as wolves," the researchers wrote in their report.

"More studies are necessary to understand how many wolves are needed in managed ecosystems," Ripple said. "It is likely that wolves need to be maintained at sufficient densities before we see their resulting effects on ecosystems."

"The preservation or recovery of large predators may represent an important conservation need for helping to maintain the resiliency of northern forest ecosystems," the researchers concluded, "especially in the face of a rapidly changing climate."

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Tuesday, March 6, 2012

Wolverine Ecology & Conservation - Yellowstone National Park

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The Northern Rockies Conservation Cooperative (NRCC) has partnered with the U.S. Forest Service, National Park Service, Yellowstone Park Foundation, and others to research wolverine ecology in Glacier & Yellowstone National Parks. These two projects lead to an increased understanding of wolverine distribution and residency, reproductive characteristics, habitat selection, food habits, connectivity of populations, and population parameters such as survival rates, birth rates, and dispersal. Additionally, public education components of these projects foster appreciation and support for wolverine conservation.

Here are excerpts from their Wolverine Conservation in Yellowstone National Park: Final Report

Wolverines in the contiguous United States are a strong concern for federal land managers and the public. The species was designated a candidate species (warranted for listing under the Endangered Species Act, but precluded by work on species of higher priority) by the US Fish and Wildlife Service in 2010. Wolverines are particularly vulnerable to extirpation due to their low numbers and large spatial requirements (Banci 1994; Copeland and Whitman 2003). Wolverine populations in the conterminous United States are small and isolated as compared to those in Canada due to naturally fragmented habitat (Aubry et al. 2007; Ruggerio et al. 2007) and infrequent exchange of individuals between mountain ranges (Cegelski et al. 2003; Kyle and Strobeck 2001, 2002). These attributes contribute to low genetic effective population sizes and low population viability (US Fish and Wildlife Service 2008). Due to its importance for the security and thermoregulation of neonates, spring snow cover may limit the wolverine’s distribution and abundance, yet this habitat component is declining across the species’ geographic range due to global climate change (Aubry et al. 2007; Copeland et al. 2010).

The wolverine is one of the least studied carnivores in North America, particularly in the contiguous United States where it occurs at the southern extent of its range (Ruggiero et al. 2007). Previous reports, surveys, and sightings records suggest that wolverines historically occurred throughout the Greater Yellowstone Ecosystem (Skinner 1927; Smith 1955; Mobley 1962; Hoak et al. 1982; Groves 1988; Consolo-Murphy and Meagher 1995; Robinson and Gehman 1998; Murphy et al. 2004).

The Wildlife Conservation Society is conducting a long-term study in the western and southern portion of the ecosystem (Inman et al. 2007a, 2008). However, little information is available concerning this species’ distribution and ecology in Yellowstone National Park and the adjoining national forests along the park’s northeast, east, and southeast boundary.

Our study objectives were to document (1) the distribution of wolverines in Yellowstone and eastern portion of the ecosystem; (2) their population characteristics, including reproduction, survival, sources of mortality, and food habits; (3) their habitat requirements, particularly those related to natal and maternal denning; and (4) their movements, including any that provide connectivity with populations in other ecosystems. To improve support for its conservation, it was also our aim to increase public awareness of this unique and mysterious carnivore (Appendix 1).

We documented wolverine distribution and population characteristics from 2005 to 2009 in Yellowstone National Park and its neighboring wilderness areas along the park’s east, northeast, and south boundaries by capturing and monitoring radio-marked individuals, and conducting surveys for their tracks during winter. We captured four individuals and collaboratively monitored three others, including two immigrants, that were previously marked by Wildlife Conservation Society biologists in the western portion of the Yellowstone ecosystem.

Wolverines in our study area selected habitats above 2,450 meters (8,000 ft), that is, in the Hudsonian (boreal) life zone, but did not use alpine habitats extensively.

Live-trapping, telemetry data, and surveys for tracks indicated that wolverine numbers and distribution were more limited than expected, despite the fact that two contemporary models estimated an extensive coverage of wolverine habitat in the area. Wolverines occurred in the Absaroka-Beartooth Wilderness along the north boundary of the park, and at the southeast corner (Thorofare region) and the adjoining Washakie and Teton Wilderness areas. When conducting helicopter-based surveys for tracks during winter, we did not detect any wolverines in the park interior, including the portion of the Gallatin Range inside the park; the Washburn and Snake River Ranges; the Central and Madison Plateaus; and the Bechler region. We also did not detect resident wolverines in the North Absaroka Wilderness and the adjoining areas along the east boundary, including the upper Lamar River. Surveys for ungulates in this area during the winter did not indicate that the availability of carrion significantly limited wolverine numbers and distribution, although our anecdotal observations suggested that winter food might be limited in the heavily forested portions of interior Yellowstone.

Wolverine home ranges did not overlap, and radio-marked individuals did not make extra-home range movements to forage in the major ungulate winter ranges in and near our study area, including the Pelican and Hayden Valleys, and the northern winter range. Our limited demographic data suggested that reproductive rates of wolverines were low, that home ranges were large, and that rates of survival were similar to estimates for other populations in the conterminous United States. The dynamics and distribution of our population appeared to be strongly linked to ingress from well-established populations in other parts of the ecosystem, rather than to recruitment of offspring born to our resident females.

We developed and tested a reliable method to rapidly assess wolverine distribution over large areas using helicopter-based searches for tracks during the winter. We were highly successful in finding tracks of resident, radio-marked wolverines during both preliminary tests (searches in 10 x 10 km survey [grid] cells) on a Wildlife Conservation Society study site, and when applying our refined technique to wolverines on our study area. This survey method can be broadly applied to the incised terrain typical of the Rocky Mountains as a first step in assessing wolverine populations, provided that surveys are adequately replicated. We recommend that biologists continue to investigate the factors that limit the growth of wolverine populations, particularly in areas such as ours where models suggest that suitable habitat is abundant.

Rare Wolverine Photographed in Montana

The Wildlife Conservation Society recently released this camera-trap photo of a wolverine retrieving bait placed in a tree in Montana.

The frame upon which the animal climbs is designed so that the unique markings on the underside of the wolverine are revealed to the motion-sensing camera.

Scientists use these markings to identify individual animals and document their distribution and range.

WCS’s eight-year study of wolverines in the Greater Yellowstone Ecosystem has led to a better understanding of wolverine ecology and will help inform conservation strategies so that this rare species can survive despite the 21st century conservation challenges it faces. An estimated 250-300 wolverines remain in the “lower 48,” where they occupy about half of their former range in high alpine peaks of the western United States.

Tuesday, February 21, 2012

Oregon's lone wolf pack threatened

Journey, an intrepid gray wolf from Oregon's lone wolf pack, made history last year when he traveled more than 1000 miles to become the first wolf in California in nearly a century.

Now Journey's family, the Imnaha pack, is under attack again at home, this time by the Oregon Cattleman's Association, which is pushing a law that would allow for the annihilation of the pack.

Here's why:
A pack of wolves roaming grasslands in Eastern Oregon killed another cow over the weekend.

The Oregon Department of Fish and Wildlife said a yearling heifer was found dead on a ranch east of Joseph in Wallowa County. ODFW officials said the rancher had coraled his 700 cattle Sunday night in a pasture near his home and that the wolves broke in and chased them out, killing a heifer. The wolves returned the next night to the same ranch but no cows were killed.

Russ Morgan, ODFE’s wolf coordinator, said the Imnaha pack has killed 19 cows since spring 2010. Usually wolves go after calves, which are the easiest prey, but the past three cows killed were adults or adult-sized, Morgan said.

“It’s worrying for livestock producers,” he said. “It’s an alarming trend.”

The agency would like to kill two wolves in the pack of at least five animals but a court-ordered stay halted that plan Oct. 5. Wildlife advocates, who took the agency to court, want the state to focus more preserving gray wolves which are protected in Oregon as an endangered species.

But:
Rob Klavins of Oregon Wild said that the number of livestock killed by gray wolves is miniscule compared with the numbers that die being born, in severe weather or from disease. Ranchers also lose cows to thieves.



The Imnaha pack is the first wolf pack in Oregon in more than 60 years. But instead of protecting and celebrating the return of the species, special interests in Oregon are working to eliminate wolves for fear of livestock depredation.


Imnaha Pack alpha male (ODFW)


The wolf pack was the first to establish and produce pups in the state in more than 60 years. While measures should be taken to prevent depredation of livestock, there are better ways to keep cattle safe than killing the family of Journey, who captured the nation's imagination with its thousand-mile expedition to become the first wolf in California in nearly a century.

Last fall, the Center for Biological Diversity and allies won an emergency stay of execution from the Oregon Court of Appeals that stopped the state from killing two wolves in the pack -- a stay that remains in place while the Cattlemen's Association pushes this appalling bill.

Tuesday, February 14, 2012

Wolves to be Poisoned Over Tar Sands in Canada

Expanding oil and gas production is contributing to the decline of caribou herds in Alberta.


Complete National Wildlife Foundation article


Incredibly, Canada’s proposed solution to habitat destruction from tar sands development is to destroy the wolves that prey on caribou, instead of protecting their habitat.

Two particularly repugnant methods of destroying wolves – shooting wolves from helicopters and poisoning wolves with baits laced with strychnine – would be carried out in response to the caribou declines.

Strychnine is a deadly poison known for an excruciating death that progresses painfully from muscle spasms to convulsions to suffocation, over a period of hours. Wildlife officials will place strychnine baits on the ground or spread them from aircraft in areas they know wolves inhabit. In addition to wolves, non-target animals like raptors, wolverines and cougars will be at risk from eating the poisoned baits or scavenging on the deadly carcasses of poisoned wildlife.


Canada’s Minister of Environment Peter Kent said in September that thousands of Alberta wolves will need to be killed to rescue caribou impacted by tar sands development.

“Culling is an accepted if regrettable scientific practice and means of controlling populations and attempting to balance what civilization has developed. I’ve got to admit, it troubles me that that’s what is necessary to protect this species,” Kent commented.

Simon Dyer of the Pembina Institute estimates that many thousands of wolves could be destroyed over five years under Canada’s proposed plan.

The minister has it backwards. Rather than killing wolves, he should be stopping the habitat destruction and restoring habitat associated with tar sands production. Without healthy habitat, the decline of caribou is inevitable, no matter how wolves are managed. If Canada wants to protect caribou herds, the first priority should be protection and restoration of caribou habitat.

Wednesday, February 8, 2012

Helicopter Hunt In Idaho?


Reasons given for wolf control action and helicopter use in the Lolo Zone.


Idaho Fish and Game
has a study area within the Lolo Zone to collect detailed information on wolves and prey populations in addition to broader-scale information gathered for the entire zone. There are at least 12 packs in the Lolo including five packs that travel back and forth between Idaho and Montana. Fish and Game will continue to collect information to evaluate the effectiveness of control actions in meeting population goals for all big game species. Lolo elk populations have been in decline for years, dating back to the early 1990s. Fish and Game has conducted extensive research that indicates wolf predation is the leading cause of death of adult cow elk and calves older than six months, while black bear and mountain lion predation is the leading cause of death for younger elk calves.

Although Fish and Game’s elk objectives for the Lolo Zone are set below historic population highs to address declines in habitat quality, these objectives aren’t being achieved. Fish and Game has been working with federal land managers for several years to improve habitat in the Lolo Zone. Public hunting of black bears and mountain lions in the Lolo Zone appears to be meeting Fish and Game’s objectives for reducing elk calf predation by these species. Public harvest of wolves in the Lolo Zone, however, is well below objectives for reducing wolf predation on elk. As of December 15, 2011, the public had harvested only 7 wolves.

Fish and Game’s goal is to reduce the wolf population in the Lolo Zone to 20 to 30 wolves in 3 to 5 packs for a period of 5 years to give Lolo elk populations a chance to recover. Assuming public harvest of wolves remains low in the Lolo Zone, Fish and Game will conduct agency control actions through a combination of trapping and aerial control. These actions are consistent with its predation management plan for the Lolo Zone. Fish and Game’s predation management plan is based on research information and data regarding predator and prey populations.

Even while wolves in the Lolo Zone were on the Endangered Species List, there was a process for U.S. Fish and Wildlife to approve reducing local wolf populations to address unacceptable impacts to elk herds. Fish and Game was in the process of obtaining U.S. Fish and Wildlife Service approval for wolf reductions in the Lolo Zone through Endangered Species Act rules when wolves were delisted. Scientific experts outside the agency have reviewed the framework for Fish and Game’s proposal to reduce the Lolo wolf population and underlying research.

Idaho Fish and Game does not have specific details regarding Lolo aerial control actions at this time. Fish and Game will provide information regarding wolf control actions in monthly wolf management updates that will be posted on the Fish and Game website: http://fishandgame.idaho.gov

Documents:

IDFG Lolo Predation Management Plan

IDFG Wolf Management (Harvest Information, Monthly Management Reports)


USDA Wildlife Services . The USDA Wildlife Services Environmental Assessment, evaluating methods for controlling wolf populations in Idaho under the National Environmental Policy Act