Threat of predation: do ungulates behave aggressively towards different members of a coyote pack?

1999 ◽  
Vol 77 (3) ◽  
pp. 499-503 ◽  
Author(s):  
Eric M Gese
Keyword(s):  
Body Size ◽  
Aggressive Behavior ◽  
Cervus Elaphus ◽  
Yellowstone National Park ◽  
National Park ◽  
Bison Bison ◽  
Antilocapra Americana ◽  
Wild Canids ◽  
Pronghorn Antelope ◽  
Large Groups

Wild ungulates have evolved a variety of antipredator strategies to deter or escape predation by carnivores. Among wild canids, the dominant pair of a pack often initiates attacks upon prey. Previous observations in Yellowstone National Park, Wyoming, showed that the alpha pair in a coyote (Canis latrans) pack most often leads attacks on ungulates during winter. We were interested in determining whether ungulates can distinguish (perhaps by body size or posture) which members of a coyote pack are the alpha individuals, and whether they initiate and direct aggressive behavior towards those members of the pack that pose the greatest threat of predation to themselves and (or) their offspring. During 2507 h of behavioral observations on 54 coyotes between January 1991 and June 1993, we observed 51 interactions between coyotes and adult elk (Cervus elaphus), bison (Bison bison), and pronghorn antelope (Antilocapra americana) in Yellowstone National Park. The interactions analyzed here are those in which the ungulate appeared to initiate aggressive behavior towards the coyote(s) and were not a response to an attack by the predators. We found that aggression by ungulates towards coyotes was highest during the summer months, when calves and fawns were present; female ungulates were more frequently aggressive than males. The frequency of aggression of adult ungulates towards small and large groups of coyotes was equal to the frequency of occurrence of these groups. Ungulates directed aggressive behavior more frequently towards alpha coyotes and were less aggressive towards beta coyotes and pups. Large ungulates, particularly elk and bison, appeared to perceive that alpha coyotes posed a greater threat to themselves and their offspring. The smaller ungulate, the pronghorn antelope, directed aggressive behavior equally towards all coyotes. Adult ungulates were probably responding to the larger body size of the alpha coyotes and the tendency of alpha coyotes to travel at the front of the pack.

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.

scholarly journals Unusual Behavior by Bison, Bison bison, Toward Elk, Cervus elaphus, and Wolves, Canis lupus

2004 ◽  
Vol 118 (1) ◽  
pp. 115 ◽  
Author(s):  
L. David Mech ◽  
Rick T. McIntyre ◽  
Douglas W. Smith
Keyword(s):  
Cervus Elaphus ◽  
Canis Lupus ◽  
Yellowstone National Park ◽  
National Park ◽  
Bison Bison ◽  
Unusual Behavior

Incidents are described of Bison (Bison bison) in Yellowstone National Park mauling and possibly killing a young Elk (Cervus elaphus) calf, chasing wolves (Canis lupus) off Elk they had just killed or were killing, and keeping the wolves away for extended periods. During one of the latter cases, the Bison knocked a wolf-wounded Elk down. Bison were also seen approaching wolves that were resting and sleeping, rousting them, following them to new resting places and repeating this behavior. These behaviors might represent some type of generalized hyper-defensiveness that functions as an anti-predator strategy.

scholarly journals Effects of Domestic Livestock and Wildlife Grazing in Grand Teton National Park

1990 ◽  
Vol 14 ◽  
pp. 103-104
Author(s):  
Michael Smith ◽  
Jerrold Dodd
Keyword(s):  
Cervus Elaphus ◽  
National Park ◽  
Odocoileus Hemionus ◽  
Bison Bison ◽  
Antilocapra Americana ◽  
Grand Teton National Park ◽  
Jackson Hole ◽  
Domestic Livestock ◽  
Wildlife Populations ◽  
Park Area

The Snake River plains and foothill areas of Jackson Hole have been grazed by domestic livestock since settlement of the area. Wildlife populations, including elk (Cervus elaphus), buffalo (Bison bison), mule deer (Odocoileus hemionus), and antelope (Antilocapra americana) have historically used the area. Moose (Alces alces) are currently relatively abundant. Currently, livestock continue to use part of the area contained in Grand Teton National Park either as a concession or due to authorization by Park enabling legislation. Large grazing wildlife also inhabit the Park area. Park managers need information concerning the effects of grazing by large ungulates on vegetation resources, to achieve desired plant community goals by effectively managing grazing.

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.

Wolves, elk, and bison: reestablishing the "landscape of fear" in Yellowstone National Park, U.S.A.

2001 ◽  
Vol 79 (8) ◽  
pp. 1401-1409 ◽  
Author(s):  
John W Laundré ◽  
Lucina Hernández ◽  
Kelly B Altendorf
Keyword(s):  
Cervus Elaphus ◽  
Canis Lupus ◽  
Yellowstone National Park ◽  
National Park ◽  
Social Groups ◽  
Bison Bison ◽  
Landscape Of Fear ◽  
Behavioural Responses ◽  
The Social ◽  
Second Year

The elk or wapiti (Cervus elaphus) and bison (Bison bison) of Yellowstone National Park have lived in an environment free of wolves (Canis lupus) for the last 50 years. In the winter of 1994-1995, wolves were reintroduced into parts of Yellowstone National Park. Foraging theory predicts that elk and bison would respond to this threat by increasing their vigilance levels. We tested this prediction by comparing vigilance levels of elk and bison in areas with wolves with those of elk still in "wolf-free" zones of the Park. Male elk and bison showed no response to the reintroduction of wolves, maintaining the lowest levels of vigilance throughout the study ([Formula: see text]12 and 7% of the time was spent vigilant, respectively). Female elk and bison showed significantly higher vigilance levels in areas with wolves than in areas without wolves. The highest vigilance level (47.5 ± 4.1%; mean ± SE) was seen by the second year for female elk with calves in the areas with wolves and was maintained during the subsequent 3 years of the study. As wolves expanded into non-wolf areas, female elk with and without calves in these areas gradually increased their vigilance levels from initially 20.1 ± 3.5 and 11.5 ± 0.9% to 43.0 ± 5.9 and 30.5 ± 2.8% by the fifth year of the study, respectively. We discuss the possible reasons for the differences seen among the social groups. We suggest that these behavioural responses to the presence of wolves may have more far-reaching consequences for elk and bison ecology than the actual killing of individuals by wolves.

scholarly journals Coyote, Canis latrans, Predation on a Bison, Bison bison, Calf in Yellowstone National Park

2009 ◽  
Vol 123 (3) ◽  
pp. 260 ◽  
Author(s):  
J. W. Sheldon ◽  
Gregory Reed ◽  
A. Cheyenne Burnett ◽  
Kevin Li ◽  
Robert L. Crabtree
Keyword(s):  
Adult Male ◽  
Yellowstone National Park ◽  
National Park ◽  
Canis Latrans ◽  
Bison Bison ◽  
Alpha Male ◽  
Complete Observation

We observed a single adult male Coyote (Canis latrans) kill a Bison (Bison bison) calf in Yellowstone National Park. The predation is, to our knowledge, the only direct and complete observation of a lone Coyote capturing and killing a Bison calf. The bison calf had unsuccessfully attempted to ford a river with a group and subsequently become stranded alone in the territory of a six-year-old alpha male Coyote.

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 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.

Sexual segregation in bison: a test of multiple hypotheses

Behaviour ◽  
2005 ◽  
Vol 142 (7) ◽  
pp. 897-927 ◽  
Author(s):  
Eric W. Schaad ◽  
David S. Wiseman ◽  
Royce R. Huber ◽  
Michael S. Mooring ◽  
Dominic D. Reisig ◽  
...  
Keyword(s):  
Body Size ◽  
Predation Risk ◽  
Sexual Segregation ◽  
Bison Bison ◽  
Sexually Dimorphic ◽  
Activity Budgets ◽  
Single Sex ◽  
Multiple Hypotheses ◽  
Mixed Groups ◽  
Large Groups

AbstractSexual segregation, in which males and females form separate groups for most of the year, is common in sexually dimorphic ungulates. We tested multiple hypotheses to explain sexual segregation in bison (Bison bison) at National Bison Range, Montana and Fort Niobrara National Wildlife Refuge, Nebraska during June-August of 2002-2003. Fieldwork involved use of GPS to record space use by segregated groups, vegetation transects to measure forage availability, fecal analyses to document diet composition and quality, and behavioural observations to characterize activity budgets. During sexual segregation, males in bull groups used areas with greater per capita abundance of forage, higher proportion of weeds, and less nutritious grasses (as indicated by lower % fecal nitrogen) compared with females in cow or mixed groups. However, there was no difference between the sexes in activity budgets, predation risk factors, or distance to water. Single-sex bull groups were no more synchronized in activity than mixed groups. These results support the 'sexual dimorphism-body size hypothesis', which proposes that males segregate from females because their larger body size requires more abundant forage, while longer ruminal retention permits efficient use of lower-quality forage. The gastrocentric model, based on the digestive physiology and foraging requirements of dimorphic ungulates, supplies the most likely proximate mechanism for bison sexual segregation. Our results would also partly support the 'reproductive strategy-predation risk hypothesis' if females form large groups to reduce predation risk. The predictions of the 'activity budget hypothesis' were not supported for bison.

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