Wolves, elk, and aspen in the winter range of Jasper National Park, Canada

2007 ◽  
Vol 37 (10) ◽  
pp. 1873-1885 ◽  
Author(s):  
R. L. Beschta ◽  
W. J. Ripple
Keyword(s):  
Predation Risk ◽  
Populus Tremuloides ◽  
Cervus Elaphus ◽  
National Park ◽  
Trophic Cascades ◽  
Population Data ◽  
Jasper National Park ◽  
Control Programs ◽  
Winter Range ◽  
Human Use

We undertook a retrospective study of aspen age structure in the winter range of Jasper National Park to assess potential trophic cascades in wolf–elk–aspen systems. We compiled historical wolf ( Canis lupus Linnaeus, 1758) and elk ( Cervus elaphus Linnaeus, 1758) population data and, in 2005, sampled 42 trembling aspen ( Populus tremuloides Michx.) stands within the Palisades site along the Athabasca Valley near Jasper townsite and another 30 stands within the Willow Creek site in a relatively remote portion of the park. Results indicated that aspen recruitment (suckers or seedlings growing into tall saplings and trees) occurred at both sites in the early 1900s but decreased in the 1940s as elk numbers were reaching a maximum. Wolves were largely eliminated from the park in the mid-1900s, and aspen recruitment during that time ceased at both sites, apparently because of heavy browsing by elk. With recovery of wolf populations in the late 1960s and increasing predation risk, elk use of the Willow Creek site declined, and aspen recruitment resumed. However, at the Palisades site, an area of relatively low predation risk due to human use and developments, renewed aspen recruitment has not occurred. Results indicate that historical wolf or ungulate control programs and human developments influenced trophic cascades involving wolves, elk, and aspen in these winter ranges.

scholarly journals Wolf, Canis lupus, Avoidance Behaviour of American Elk, Cervus elaphus, in Jasper National Park, Alberta

2009 ◽  
Vol 123 (3) ◽  
pp. 236 ◽  
Author(s):  
Dick Dekker ◽  
Greg Slatter
Keyword(s):  
Cervus Elaphus ◽  
Canis Lupus ◽  
National Park ◽  
Radio Signal ◽  
Athabasca River ◽  
Jasper National Park ◽  
Winter Range ◽  
Wooded Area ◽  
Human Habitation ◽  
Local Herd

An American Elk calf (Cervus elaphus) that was captured near human habitation in Jasper National Park, Alberta, was fitted with a radio-collar and released 40 km away in the park's main valley of the Athabasca River. The calf joined a local herd of elk, and its radio signal revealed that the elk, in two months' time, travelled eight times back and forth between the herd's traditional semi-open winter range at Devona and a largely wooded area at Rocky River >3 km away. Each time, on their trans-valley route the elk crossed a busy highway, a railway, and a partly frozen river. Sightings of elk and Wolves (Canis lupus) were inversely correlated on 97 days of observation at Devona. We conclude that the elk's migrations were prompted by their urge to avoid and flee from Wolves, which were common at both locations.

scholarly journals Landscape-Level Interactions Among Ungulates, Vegetation, and Large-Scale Fires in Northern Yellowstone National Park

1992 ◽  
Vol 16 ◽  
pp. 206-211
Author(s):  
Monica Turner ◽  
Yegang Wu ◽  
Scott Pearson ◽  
William Romme ◽  
Linda Wallace
Keyword(s):  
Populus Tremuloides ◽  
Cervus Elaphus ◽  
Yellowstone National Park ◽  
National Park ◽  
Large Scale ◽  
Field Studies ◽  
Bison Bison ◽  
Fire Size ◽  
Management Scenarios ◽  
Winter Range

The scale of the 1988 fires in Yellowstone National Park (YNP) raised numerous questions for the management of natural areas subject to large, infrequent disturbances. An important management issue in YNP involves the interaction of large-scale fire with the large assemblage of native ungulates and vegetation dynamics in the landscape. We used landscape modeling and field studies to address basic questions about the effects of fire scale and heterogeneity on resource utilization and survival of free-ranging elk (Cervus elaphus) and bison (Bison bison), and the production and regeneration of preferred forage grasses and aspen in northern Yellowstone Park. More specifically, we asked (1) how fire size interacts with winter severity to control ungulate feeding behavior and survival, both in the initial postfire winter, when fire reduces forage, and in later postfire winters, when fire augments forage; (2) how fire pattern (e.g., clumped vs. dispersed burn sites) modifies the effects of fire size; (3) which environmental factors, including fire, influence selection of feeding areas by wintering ungulates at a variety of scales, from a single feeding station to the entire northern winter range; and (4) how the size and spatial pattern of burning influence regeneration of aspen (Populus tremuloides), a preferred and heavily browsed species in YNP. We focus on elk and bison because these are by far the most numerous ungulates in the area (Houston 1982), and we have chosen to examine winter grazing and browsing for several reasons. Winter range conditions are the primary determinant of ungulate survival and reproduction in Yellowstone, and winter utilization of the vegetation by ungulates appears to be intense in some areas. Ungulates make distinct foraging choices in the winter as in the rest of the year, and burn patterns may influence those choices in ways that we represent as hypotheses described later. In addition, the activities of animals can be readily monitored in the winter, and the exact locations of feeding and bedding sites can be determined. Travel routes are easily monitored, and the ability to sight animals is high; therefore, group locations and sizes can be readily determined. This research complements ongoing studies in Yellowstone by expanding the spatial scale at which plant-herbivore dynamics are considered and by explicitly addressing the effects of spatial heterogeneity. We produced a spatially explicit simulation model of the winter range that predicts plant and ungulate dynamics under varying fire sizes, fire patterns, winter weather scenarios. The model and field studies will generate quantitative comparisons of the effects of large and small fires on ungulate survival and will thereby permit the simulation of the effects of alternative fire management scenarios.

scholarly journals Declines of Bighorn Sheep, Ovis canadensis, on Deteriorating Winter Range in Jasper National Park, Alberta, 1981-2010

2009 ◽  
Vol 123 (2) ◽  
pp. 157 ◽  
Author(s):  
Dick Dekker
Keyword(s):  
Cervus Elaphus ◽  
National Park ◽  
Full Range ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Athabasca River ◽  
Jasper National Park ◽  
Winter Range ◽  
Salsola Kali ◽  
Average Annual Precipitation

Bighorn Sheep (Ovis canadensis) wintering in the lower Athabasca River valley of Jasper National Park, Alberta, were monitored from 1981 to 2010 by recording maximum band sizes per annum on two traditional but separate sheep ranges. In study area #1, the ram band declined significantly from a 20-year mean of 18 in the period 1981-2001 to a 5-year mean of 11 in the period 2001-2006, with a slight recovery in 2006-2010. Ewes in area #1 dwindled from a mean of 20 in the period 1981-1995 to zero in the period 1995-2010. In area #2, the ewe band dropped significantly from a mean of 40 in the period 1981-2001 to 24 in the period 2001-2010. The declines in area #1 coincided with an invasion of Russian Thistle (Salsola kali). Range conditions in area #2 deteriorated following four years with lower than average annual precipitation. The mean lamb:ewe ratio in area #2, pooled for 29 years, was 22:100 (n = 646). The sheep were protected from hunting, but were subject to a full range of indigenous carnivores. However, predation did not appear to be the primary cause of the declines, nor was competition for forage with American Elk (Cervus elaphus).

scholarly journals Trophic Cascades and Historic Aspen Recruitment in the Gallatin Elk Winter Range of Southwest Montana

2005 ◽  
Vol 29 ◽  
pp. 89-95
Author(s):  
Joshua Halofsky ◽  
William Ripple
Keyword(s):  
Populus Tremuloides ◽  
Cervus Elaphus ◽  
Canis Lupus ◽  
National Park ◽  
Fire Suppression ◽  
Gray Wolf ◽  
Climate Trends ◽  
Wolf Predation ◽  
Winter Range ◽  
Conifer Invasion

The extirpation of the gray wolf (Canis lupus) by 1930 in Yellowstone National Park (YNP) provided us with an opportunity to study historic aspen (Populus tremuloides ) recruitment with and without a top carnivore predator present. Herbivory, climate trends, fire records, and current conifer invasion were also examined within the context of aspen recruitment. We obtained tree cores and diameter at breast height measurements to create an aspen age-diameter relationship which we used to approximate aspen origination dates. One elk (Cervus elaphus) exclosure, erected in 1945 within the same elk winter range, was compared to the rest of the winter range. Consistent recruitment inside the exclosure began in the 1940s and has continued into the present. Outside of the exclosure, aspen recruitment began decreasing in the 1930s and ceased in the 1950s. Within the scope of the study, we found little correlative evidence between aspen decline and climate trends, conifer invasion, or fire suppression. The results are suggestive of a trophic cascade between aspen recruitment, and historical elk browsing activities as affected by the absence or presence of wolf predation.

Long-term aspen dynamics, trophic cascades, and climate in northern Yellowstone National Park

2016 ◽  
Vol 46 (4) ◽  
pp. 548-556 ◽  
Author(s):  
Robert L. Beschta ◽  
Luke E. Painter ◽  
Taal Levi ◽  
William J. Ripple
Keyword(s):  
Populus Tremuloides ◽  
Cervus Elaphus ◽  
Yellowstone National Park ◽  
National Park ◽  
Average Density ◽  
Drought Severity ◽  
Quaking Aspen ◽  
Climatic Trend ◽  
Predator Prey

We report long-term patterns of quaking aspen (Populus tremuloides Michx.) recruitment for five ungulate exclosures in the northern ungulate winter range of Yellowstone National Park. Aspen recruitment was low (<3 aspen·ha−1·year−1) in the mid-1900s prior to exclosure construction due to herbivory by Rocky Mountain elk (Cervus elaphus Linnaeus, 1758) but increased more than 60-fold within 25 years after exclosure construction despite a drying climatic trend since 1940. Results support the hypothesis that long-term aspen decline in Yellowstone’s northern range during the latter half of the 20th century was caused by high levels of ungulate herbivory and not a drying climate. Gray wolves (Canis lupus Linnaeus, 1758) were reintroduced during 1995–1996. For the period 1995–2012, we summarized annual predator–prey ratios, ungulate biomass, and drought severity. The average density of young aspen increased from 4350 aspen·ha−1 in 1997–1998 to 8960 aspen·ha−1 in 2012; during the same time period, those >1 m in height increased over 30-fold (from 105 to 3194 aspen·ha−1). Increased heights of young aspen occurred primarily from 2007 to 2012, a period with relatively high predator–prey ratios, declining elk numbers, and decreasing browsing rates. Consistent with a re-established trophic cascade, aspen stands in Yellowstone’s northern range have increasingly begun to recover.

scholarly journals Landscape-Level Interactions Among Ungulates, Vegetation, and Large-Scale Fires in Northern Yellowstone National Park

1991 ◽  
Vol 15 ◽  
pp. 263-275
Author(s):  
Monica Turner ◽  
Yegang Wu ◽  
William Romme ◽  
Linda Wallace
Keyword(s):  
Spatial Pattern ◽  
Cervus Elaphus ◽  
Resource Use ◽  
Yellowstone National Park ◽  
National Park ◽  
Large Scale ◽  
Field Studies ◽  
Bison Bison ◽  
Fire Size ◽  
Winter Range

The scale of the 1988 fires in Yellowstone National Park (YNP) raised numerous questions for the management of natural areas subject to large, infrequent disturbances. An important management issue in YNP involves the interaction of large-scale fire with the large assemblage of native ungulates and vegetation dynamics in the landscape. In this 2-year research project, we are using landscape modeling and field studies to address basic questions about the effects of fire scale and heterogeneity on (1) resource utilization and survival of free-ranging elk (Cervus elaphus) and bison (Bison bison) and (2) the production and regeneration of preferred forage grasses and aspen in northern YNP. We are testing a series of eight hypotheses within the framework of two basic questions. First, we ask whether there are thresholds in fire size that interact with winter severity and ungulate density to determine ungulate resource use and survival on the winter range in northern YNP. This question focuses on the effects of fire size, regardless of the spatial pattern of burning. Second we ask, if large fires occur, does the spatial distribution of burned areas (and hence of higher quality forage) influence ungulate resource use during winters subsequent to the first post-fire year. In this question, we are addressing the effects of spatial pattern on herbivory. We focus on elk and bison because these are by far the most numerous ungulates in the area (Houston 1982), and we have chosen to examine winter grazing and browsing for several reasons. Winter range conditions are the primary determinant of ungulate survival and reproduction in Yellowstone, and winter utilization of the vegetation by ungulates appears to be intense in some areas. Ungulates make distinct foraging choices in the winter as in the rest of the year, and burn patterns may influence those choices in ways that we represent as hypotheses described later. In addition, the activities of animals can be readily monitored in the winter, and the exact locations of feeding and bedding sites can be determined. Travel routes are easily monitored, and the ability to sight animals is high; therefore, group locations and sizes can be readily determined. This research complements ongoing studies in YNP by expanding the spatial scale at which plant-herbivore dynamics are considered and by explicitly addressing the effects of spatial heterogeneity. Our research will produce a spatially explicit simulation model of the 78,000 ha winter range that predicts plant and ungulate dynamics under varying fire sizes, fire patterns, winter weather scenarios, and ungulate densities. The model and field studies will allow quantitative comparisons of the effects of large and small fires on ungulate survival and will thereby permit the simulation of the effects of alternative fire management scenarios.

Are migrant and resident elk (Cervus elaphus) exposed to similar forage and predation risk on their sympatric winter range?

Oecologia ◽  
2010 ◽  
Vol 164 (1) ◽  
pp. 265-275 ◽  
Author(s):  
Barry G. Robinson ◽  
Mark Hebblewhite ◽  
Evelyn H. Merrill
Keyword(s):  
Predation Risk ◽  
Cervus Elaphus ◽  
Winter Range

Context dependence of elk (Cervus elaphus) vigilance and wolf (Canis lupus) predation risk

2014 ◽  
Vol 92 (8) ◽  
pp. 727-736 ◽  
Author(s):  
Cristina Eisenberg ◽  
David E. Hibbs ◽  
William J. Ripple ◽  
Hal Salwasser
Keyword(s):  
Predation Risk ◽  
Group Size ◽  
Cervus Elaphus ◽  
Canis Lupus ◽  
National Park ◽  
Forest Edge ◽  
The North ◽  
Edge Group ◽  
North Fork ◽  
Complex Picture

To assess the relationship between predation risk perceived by elk (Cervus elaphus L., 1758) as evidenced by vigilance, we conducted focal animal observations in elk winter range. We stratified our observations in Glacier National Park, Montana, USA, and Waterton Lakes National Park, Alberta, Canada, in valleys with three wolf (Canis lupus L., 1758) population levels (Saint Mary Valley: no wolf; Waterton Valley: moderate wolf; North Fork Valley: high wolf). Although the lowest elk vigilance occurred in Saint Mary and the highest in the North Fork, our analysis revealed a complex picture. Our model included distance to forest edge, group size, distance to road, social class, and impediments to detecting and escaping wolves. In Saint Mary, none of the variables were significant. In Waterton, vigilance decreased as elk group size increased (p < 0.00001) and increased as impediments increased (p = 0.0005). In the North Fork, vigilance increased as group size increased (p = 0.03), bulls were more vigilant (p = 0.02), and the interaction between group size and impediments was significant (p = 0.03). Where a high wolf population existed, elk did not exhibit uniform or expected response to predation risk factors. High wolf presence may necessitate adaptive elk behaviour that differs from response to moderate wolf presence.

scholarly journals Climate and management interact to explain the decline of woodland caribou (Rangifer tarandus caribou) in Jasper National Park

Rangifer ◽  
2012 ◽  
pp. 183-191 ◽  
Author(s):  
Mark Bradley ◽  
Lalenia Neufeld
Keyword(s):  
Climate Change ◽  
Wildlife Management ◽  
National Park ◽  
Rangifer Tarandus ◽  
Climate Data ◽  
Woodland Caribou ◽  
Predator Prey ◽  
Jasper National Park ◽  
Human Use

Woodland caribou in the southern portion of Jasper National Park have declined from an estimated 435 in the mid 1970s to a population estimate of 87 in the fall of 2009. We examined the available historical information to determine why caribou have declined. We compared three main hypotheses for caribou decline in JNP: human disturbance, climate change, and wildlife management. We used historical human use statistics, climate data, and animal abundance information to weigh the evidence for these competing hypotheses over two time scales. Caribou decline could not be attributed to changes in climate over the long-term, or an increase in human use (our proxy for disturbance). Caribou decline was attributed to a combination of climate and wildlife management. Recovery of caribou in Jasper National Park will likely be contingent on managing the interaction between the predator/prey dynamic and climate change.

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