scholarly journals Climate induced wolf prey selection in Yellowstone National Park, 1995-2015

2016 ◽  
Author(s):  
Douglas W Smith ◽  
Matthew Metz ◽  
Chris Wilmers ◽  
Daniel Stahler ◽  
Chris Geremia
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Prey Selection ◽  
Selective Advantage ◽  
Late Winter ◽  
Age Classes ◽  
Predator Prey ◽  
Wolf Predation ◽  
Management Objectives

Prey selection by wolves has been a fundamental and long-term topic of interest for wolf-prey studies. Virtually all studies conclude the selectivity of wolf predation and typically identify what made an individual vulnerable. Vulnerability, however, varies for multiple reasons and emerging research is discovering climate induced effects on prey forage altering condition and selective advantage of migration. We present data from a twenty year study of wolf-elk predation in Yellowstone National Park (YNP) which found bull elk killed more frequently in early winter after years with less snowfall compared to years with normal snowfall. Snowfall impacted summer forage, which impacted bull elk condition going into the autumn rut, which weakened elk prematurely post-rut causing them to be selected by wolves in early rather than late winter, and possibly caused more bulls to be killed overall. Bull elk ratios have declined over the last 20 years (from 40-60 to 10-15 bulls/100 cows; lower outside YNP), which has led to calls for a reduced human harvest on bulls which has been met with significant resistance. Understanding the interaction between climate, forage and wolf predation on bull elk (and other sex/age classes) will help guide management decisions and potentially sustain hunting of bulls in the long term as well as protect natural management objectives within YNP. Results will be of widespread value as they may suggest changing predator-prey dynamics across North America by making some otherwise healthy prey vulnerable to predation.

scholarly journals Climate induced wolf prey selection in Yellowstone National Park, 1995-2015

2016 ◽  
Author(s):  
Douglas W Smith ◽  
Matthew Metz ◽  
Chris Wilmers ◽  
Daniel Stahler ◽  
Chris Geremia
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Prey Selection ◽  
Selective Advantage ◽  
Late Winter ◽  
Age Classes ◽  
Predator Prey ◽  
Wolf Predation ◽  
Management Objectives

Prey selection by wolves has been a fundamental and long-term topic of interest for wolf-prey studies. Virtually all studies conclude the selectivity of wolf predation and typically identify what made an individual vulnerable. Vulnerability, however, varies for multiple reasons and emerging research is discovering climate induced effects on prey forage altering condition and selective advantage of migration. We present data from a twenty year study of wolf-elk predation in Yellowstone National Park (YNP) which found bull elk killed more frequently in early winter after years with less snowfall compared to years with normal snowfall. Snowfall impacted summer forage, which impacted bull elk condition going into the autumn rut, which weakened elk prematurely post-rut causing them to be selected by wolves in early rather than late winter, and possibly caused more bulls to be killed overall. Bull elk ratios have declined over the last 20 years (from 40-60 to 10-15 bulls/100 cows; lower outside YNP), which has led to calls for a reduced human harvest on bulls which has been met with significant resistance. Understanding the interaction between climate, forage and wolf predation on bull elk (and other sex/age classes) will help guide management decisions and potentially sustain hunting of bulls in the long term as well as protect natural management objectives within YNP. Results will be of widespread value as they may suggest changing predator-prey dynamics across North America by making some otherwise healthy prey vulnerable to 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 Prediction of Genetic Contributions and Generation Intervals in Populations With Overlapping Generations Under Selection

Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1197-1210 ◽  
Author(s):  
Piter Bijma ◽  
John A Woolliams
Keyword(s):  
Gene Flow ◽  
Overlapping Generations ◽  
Selective Advantage ◽  
Turnover Time ◽  
Breeding Value ◽  
Age Classes ◽  
Generation Interval ◽  
Young Parents ◽  
Genetic Contributions

Abstract A method to predict long-term genetic contributions of ancestors to future generations is studied in detail for a population with overlapping generations under mass or sib index selection. An existing method provides insight into the mechanisms determining the flow of genes through selected populations, and takes account of selection by modeling the long-term genetic contribution as a linear regression on breeding value. Total genetic contributions of age classes are modeled using a modified gene flow approach and long-term predictions are obtained assuming equilibrium genetic parameters. Generation interval was defined as the time in which genetic contributions sum to unity, which is equal to the turnover time of genes. Accurate predictions of long-term genetic contributions of individual animals, as well as total contributions of age classes were obtained. Due to selection, offspring of young parents had an above-average breeding value. Long-term genetic contributions of youngest age classes were therefore higher than expected from the age class distribution of parents, and generation interval was shorter than the average age of parents at birth of their offspring. Due to an increased selective advantage of offspring of young parents, generation interval decreased with increasing heritability and selection intensity. The method was compared to conventional gene flow and showed more accurate predictions of long-term genetic contributions.

State-shifts of lion prey selection in the Kruger National Park

2017 ◽  
Vol 44 (1) ◽  
pp. 28 ◽  
Author(s):  
N. T. Maruping-Mzileni ◽  
P. J. Funston ◽  
S. M. Ferreira
Keyword(s):  
National Park ◽  
Prey Selection ◽  
Management Strategies ◽  
Stable State ◽  
Kruger National Park ◽  
Ecological Processes ◽  
Policy Makers ◽  
Predator Prey ◽  
Key Indicator ◽  
Management Interventions

Aims Indicators of pending state-shifts carry value for policy makers. Predator–prey relations reflect key ecological processes that shape ecosystems. Variance in predator–prey relations may serve as a key indicator of future state-shifts. Methods Lion (Panthera leo) diet in the Kruger National Park was evaluated as such an indicator. Over the three-decade time span reviewed, variance in diet in relation to rainfall, prey abundance, management strategies and disease emergence were reviewed. Key results Rainfall patterns, both seasonal and cyclical, were identified as key drivers of predator–prey selection. However, the intensity of management in the form of artificial waterpoints overrode and confounded natural process. The results suggest that savanna systems are stable and punctuated by climatic events in the form of extreme above-average rainfall that temporarily destabilises the system. However, droughts are a cyclical part of the savanna system. Conclusion Lion prey selection did fluctuate with changing environmental conditions. Abrupt state shifts did occur; however, the ecosystem returned to a stable state. Implications State shifts in ecosystems pose key challenges to conservation managers. State shifts appear to be primarily associated with management interventions and environmental factors.

scholarly journals Temporal variation in wolf predation dynamics in the multi-prey system of northern Yellowstone National Park

2016 ◽  
Author(s):  
Matthew C Metz ◽  
Douglas W Smith ◽  
Mark Hebblewhite ◽  
Daniel R Stahler
Keyword(s):  
Temporal Variation ◽  
Yellowstone National Park ◽  
National Park ◽  
Prey Species ◽  
Bison Bison ◽  
Prey Abundance ◽  
Large Carnivores ◽  
Population Abundance ◽  
Wolf Predation ◽  
Prey System

Predation is a fundamental ecological process that shapes ecosystem structure and biodiversity. For large carnivores preying on large ungulates, predation dynamics are influenced by many factors, including climatic conditions, prey abundance, and prey body size. Evaluating the factors that influence how large carnivore predation varies among different-sized prey, both among and within prey species, is critical for understanding how large carnivores influence prey species population dynamics. Here, in the wolf (Canis lupus)-multi-prey system of northern Yellowstone National Park, we assess how temporal variation in prey abundance and vulnerability affect seasonal wolf predation patterns. More specifically, we characterize wolf predation patterns during four seasons of the year (early winter [mid-November to mid-December], late winter [March], spring [May], summer [June, July]) and evaluate the influence of inter-annual variation in the abundance of the two, primary, year-round ungulate prey (elk [Cervus elaphus], bison [Bison bison]) from 1995-2015. Our results highlight how the wolf-prey system of northern Yellowstone National Park has shifted from a wolf-elk system to a wolf-elk-bison system. That is, although elk are still the primary prey for wolves, the proportion of wolf kills that are elk has declined over the last twenty years. Now, bison are more commonly preyed on by wolves, and possibly most importantly, are increasingly scavenged. This change has occurred due to the decline in the northern Yellowstone elk population and concurrent increase in the northern Yellowstone bison population. Although wolf predation of bison is minimal and likely has no influence on bison population abundance, increased use of bison by wolves has a potential effect on wolf population abundance, and as a result, elk population abundance. Our results highlight the importance of considering how subsidies provided through preying on and scavenging secondary prey affect predator-primary prey dynamics.

scholarly journals Further Information on Ectomycorrhizal Macrofungi in the Greater Yellowstone Area

1999 ◽  
Vol 23 ◽  
pp. 149-151
Author(s):  
Joe Ammirati ◽  
M. Seidl ◽  
P. Matheny ◽  
Meinhard Moser ◽  
Bradley Kropp
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Term Study ◽  
Yellowstone Lake ◽  
Early Season ◽  
Long Term Study ◽  
Greater Yellowstone Area ◽  
Greater Yellowstone

Mushroom collecting in the Greater Yellowstone Area was relatively poor during the summer of 1999 due to a cool early season followed by dry weather during the summer. It was perhaps the poorest year of a long term study of Cortinarius, which Meinhard Moser and the late Vera and Kent McKnight began in earnest in the early 1980s; later joined by Joe Ammirati. None-the-less during the season Meinhard Moser was able to paint more than forty-five species for the monograph we are preparing on the Cortinarii of this region. At the end of the season, in late August, some good collections of Cortinarii were made at Sandpoint on Yellowstone Lake, and Lilypad Lake in Yellowstone National Park.

scholarly journals Effects of 1988 Fires on Ecology of Coyotes in Yellowstone National Park: Baseline Preceding Possible Wolf Recovery

1993 ◽  
Vol 17 ◽  
pp. 109-116
Author(s):  
Robert Crabtree
Keyword(s):  
Data Collection ◽  
Small Mammals ◽  
Yellowstone National Park ◽  
National Park ◽  
Initial Density ◽  
Mortality Data ◽  
Late Winter ◽  
Scat Analysis ◽  
Field Season ◽  
Ungulate Mortality

Sixty healthy adult coyote Canis latrans and 53, 8-12 week old pups captured at dens were radio­ tagged in the Lamar Valley and Blacktail Plateau areas of the northern range of Yellowstone National Park. Adults range in age from 1 to 12 years and average nearly 3.3 years old. Territorial packs in both study areas are adjacent, non-overlapping, contiguous, and average 15 km2. Based on information from the last four winters and data collected from 1946 to 1949, territorial areas are traditional and have changed little in the last 45 years. We estimate that 85 to 90% of coyotes on the northern range belong to packs. A territorial group or pack during the winter consists of 2 alpha individuals, 2 or 3 beta adults, and 2 or 3 adult-sized pups (average pack size = 7). Fifteen marked coyotes have died since November of 1992. Initial density estimates are 1.4 coyotes per square mile. Preliminary scat analysis suggests that small mammals, especially voles, dominate the diet with ungulate remains becoming important in May through July (presumably elk calves) and late winter (mostly scavenging). Two graduate students have finished their data collection and another student is currently working on his last field season. More than 2500 hours of foraging observations were conducted from January 1991 through June 1993 resulting in data collection on more than 4400 predation attempts on small mammals. Eight hundred and fifty hours of den observations were completed during 1992 and 1993. Beta pack members were observed to bring food to pups and protect den sites from intruders. Coyote behavior and ungulate mortality data were collected on sixty-one carcasses found during the 1992-1993 winter. Five successful and 4 unsuccessful predations by coyotes on ungulates have been seen. Coyotes appear to impact ungulate numbers in 3 ways: predation on calves and fawns shortly after birth (up to 8 weeks), predation on short-yearlings and adults during winter, and indirect impact from harassment of other predators at ungulate-kills. Coyotes may be the major ungulate predator on the northern range due to their cooperative social and foraging behavior, ability to take advantage of vulnerable ungulates, and high population levels. Wolf extirpation has probably resulted in high coyote population densities and coyotes have, at least partially, slid into this vacant niche.

Factors affecting the trappability of red foxes in Kosciusko National Park

1998 ◽  
Vol 25 (2) ◽  
pp. 199 ◽  
Author(s):  
Tania Bubela ◽  
Robert Bartell ◽  
Warren Müller
Keyword(s):  
National Park ◽  
New South ◽  
Home Ranges ◽  
Age Classes ◽  
Red Foxes ◽  
Foraging Patterns ◽  
Factors Affecting ◽  
Ski Resorts ◽  
South Wales

The factors that affect the trappability of the red fox (Vulpes vulpes L.) in alpine and subalpine New South Wales were examined by means of treadle snares. Trapping (1) on animal tracks without the use of a bait or lure, and (2) by setting snares around a bait, led to the capture of individuals of both sexes and all age-classes. A greater number of foxes was captured per number of snares set in winter than in other seasons because of the commensal foraging patterns of foxes at this time. Foxes were more likely to be caught within 100 m of their home-range boundaries during snow-free months and outside their home ranges while foraging at ski resorts in winter. Snares were found to be difficult to set, and foxes were captured in only 50% of sprung snares. Treadle snares caused no apparent long-term injuries to 40 red foxes that were radio- tracked and observed for 1–24 months after capture.

scholarly journals Temporal variation in wolf predation dynamics in the multi-prey system of northern Yellowstone National Park

2016 ◽  
Author(s):  
Matthew C Metz ◽  
Douglas W Smith ◽  
Mark Hebblewhite ◽  
Daniel R Stahler
Keyword(s):  
Temporal Variation ◽  
Yellowstone National Park ◽  
National Park ◽  
Prey Species ◽  
Bison Bison ◽  
Prey Abundance ◽  
Large Carnivores ◽  
Population Abundance ◽  
Wolf Predation ◽  
Prey System

Predation is a fundamental ecological process that shapes ecosystem structure and biodiversity. For large carnivores preying on large ungulates, predation dynamics are influenced by many factors, including climatic conditions, prey abundance, and prey body size. Evaluating the factors that influence how large carnivore predation varies among different-sized prey, both among and within prey species, is critical for understanding how large carnivores influence prey species population dynamics. Here, in the wolf (Canis lupus)-multi-prey system of northern Yellowstone National Park, we assess how temporal variation in prey abundance and vulnerability affect seasonal wolf predation patterns. More specifically, we characterize wolf predation patterns during four seasons of the year (early winter [mid-November to mid-December], late winter [March], spring [May], summer [June, July]) and evaluate the influence of inter-annual variation in the abundance of the two, primary, year-round ungulate prey (elk [Cervus elaphus], bison [Bison bison]) from 1995-2015. Our results highlight how the wolf-prey system of northern Yellowstone National Park has shifted from a wolf-elk system to a wolf-elk-bison system. That is, although elk are still the primary prey for wolves, the proportion of wolf kills that are elk has declined over the last twenty years. Now, bison are more commonly preyed on by wolves, and possibly most importantly, are increasingly scavenged. This change has occurred due to the decline in the northern Yellowstone elk population and concurrent increase in the northern Yellowstone bison population. Although wolf predation of bison is minimal and likely has no influence on bison population abundance, increased use of bison by wolves has a potential effect on wolf population abundance, and as a result, elk population abundance. Our results highlight the importance of considering how subsidies provided through preying on and scavenging secondary prey affect predator-primary prey dynamics.

scholarly journals Fire and Landscape Dyamics in Yellowstone National Park

1986 ◽  
Vol 10 ◽  
pp. 193-195
Author(s):  
William Romme ◽  
Don Despain
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
National Science Foundation ◽  
Annual Report ◽  
Patch Dynamics ◽  
National Science Foundation Grant ◽  
Forest Communities ◽  
National Science

This study is an investigation of long-term patch dynamics in the mosasic of forest communities covering the subalpine plateaus of Yellowstone National Park. The study is being supported by the National Science Foundation (Grant No. BSR - 8408181). Our specific objectives were rummarized in the 1985 Annual Report.

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