Testing hypotheses of bison population decline (1970–1999) in Wood Buffalo National Park: synergism between exotic disease and predation

2004 ◽  
Vol 82 (7) ◽  
pp. 1165-1176 ◽  
Author(s):  
Damien O Joly ◽  
François Messier
Keyword(s):  
Canis Lupus ◽  
National Park ◽  
Historical Data ◽  
Population Decline ◽  
Bison Bison ◽  
Low Density ◽  
Survival And Reproduction ◽  
Low Probability ◽  
Wood Buffalo National Park ◽  
Population Simulation

One hypothesis to explain the decline of bison (Bison bison (L., 1758)) abundance in Wood Buffalo National Park, Canada, is the "disease–predation" hypothesis where tuberculosis (Mycobacterium bovis Karlson and Lessel, 1970) and brucellosis (Brucella abortus (Schmidt, 1901)) reduce bison survival and reproduction, thus shifting bison abundance from a high-density, food-regulated equilibrium to a low-density, predator-regulated equilibrium. We use historical data on bison abundance and stochastic population simulation to examine this hypothesis. A decline in only one area of the park would discount disease as a factor, because exotic disease is present throughout the park; however, we found that decline rates were similar in the two main populations of bison. Using simulation, we found a high (68.5%) probability that a tuberculosis- and brucellosis-infected bison population experiencing predation by wolves (Canis lupus L., 1758) would stabilize at low densities (<0.83 bison/km2), which increased to 93.6% when anthrax and drowning were considered to be mortality sources. In the absence of tuberculosis and brucellosis, there was a low probability that bison would persist at this low density (<8%). These simulations suggest that an interaction between tuberculosis, brucellosis, and predation may account for the decline of bison abundance in Wood Buffalo National Park from 1970 to 1999.

The fall and rise of bison populations in Wood Buffalo National Park: 1971 to 2003

2005 ◽  
Vol 83 (9) ◽  
pp. 1195-1205 ◽  
Author(s):  
Mark Bradley ◽  
John Wilmshurst
Keyword(s):  
National Park ◽  
Census Data ◽  
Disease Incidence ◽  
Population Decline ◽  
Survival Rates ◽  
Bison Bison ◽  
Adult Survival ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Wood Buffalo National Park

Two hypotheses have been proposed to explain the decline of bison (Bison bison (L., 1758)) abundance in Wood Buffalo National Park (WBNP). The "disease–predation" hypothesis proposes that tuberculosis (Mycobacterium bovis (Karlson and Lessel 1970)) and brucellosis (Brucella abortus (Schmidt 1901)) reduce bison survival and reproduction, resulting in a low-density, predator-regulated equilibrium. The "habitat dispersion hypothesis" proposes that bison in one area of WBNP, the Peace–Athabasca Delta (Delta), have an increased risk of predation because they are concentrated in large meadows with high temporal and spatial predictability. We incorporate bison census data, calf and yearling segregation counts, reproductive rates, adult survival rates, and adult disease incidence in a stochastic population model to show that the historical decline of bison in WBNP would have occurred regardless of disease prevalence. Our model shows that survival of juveniles, the age class that is least susceptible to disease effects, was likely an important determinant of historical changes in population size. We also demonstrate that the population decline was most pronounced in the Delta and that juvenile survival was lower in the Delta, despite evidence that disease incidence was lower in the Delta than in the rest of WBNP. Lastly, the current population trend in WBNP is one of rapid increase, even in the presence of disease.

A numerical response of wolves to bison abundance in Wood Buffalo National Park, Canada

2000 ◽  
Vol 78 (6) ◽  
pp. 1101-1104 ◽  
Author(s):  
Damien O Joly ◽  
François Messier
Keyword(s):  
Population Size ◽  
Canis Lupus ◽  
National Park ◽  
Multiple Linear Regression Model ◽  
Bison Bison ◽  
Numerical Response ◽  
Wolf Population ◽  
Predator Prey ◽  
Wood Buffalo National Park ◽  
The Relationship

The numerical response of predators to changing prey density is an important component of predator-prey dynamics. We examined factors influencing two indices of wolf (Canis lupus) abundance in Wood Buffalo National Park, Canada: historical wolf pelt harvests from 1970 to 1988 and sightings of wolves by park staff on survey flights from 1973 to 1991. We tested the effect of pelt price (adjusted to 1986-equivalent Canadian dollars), number of trappers, and bison (Bison bison) population size on wolf pelt returns for an 18-year period using a multiple linear regression model. We then tested the relationship between wolf sightings on survey flights and bison population size for an overlapping 19-year period. Wolf pelt price was a significant determinant of wolf harvest, whereas numbers of bison or trappers were not significant predictors of wolf harvest. However, there was a significant relationship between wolf sightings and bison population size. This analysis suggests that wolf population size was correlated with bison numbers, similar to the numerical response seen in other wolf-prey systems.

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.

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.

Genetic variation within and relatedness among wood and plains bison populations

Genome ◽  
1999 ◽  
Vol 42 (3) ◽  
pp. 483-496 ◽  
Author(s):  
G A Wilson ◽  
C Strobeck
Keyword(s):  
Genetic Variation ◽  
National Park ◽  
Genetic Relatedness ◽  
Nuclear Material ◽  
Genetic Distances ◽  
Bison Bison ◽  
Dna Microsatellites ◽  
Island State ◽  
Wood Bison ◽  
Wood Buffalo National Park

There are two recognized subspecies of bison, wood (Bison bison athabascae) and plains (Bison bison bison) bison. The establishment of most bison populations from a small number of individuals has raised concerns about their genetic variation. To this end, 11 bison populations were surveyed with 11 microsatellite loci in order to calculate genetic variation and genetic distances. Mean number of alleles ranged between 3.18 at Antelope Island State Park (Utah) and 6.55 at Wood Buffalo National Park (Alberta and Northwest Territories). Mean heterozygosity ranged from 0.295 at Antelope Island State Park to 0.669 at Custer State Park (South Dakota). The amount of genetic variability present in the bison populations as measured by mean number of alleles and overall probability of identity was found to correlate with the number of founders for all sampled populations. The G-test for heterogeneity revealed some evidence for the existence of subpopulations at Wood Buffalo National Park, however very small genetic distances between these subpopulations suggest that nuclear material from the plains bison introduced into Wood Buffalo National Park has diffused throughout the park. Genetic distances between the sampled populations were generally larger between than within the two bison subspecies.Key words: Bison bison bison, Bison bison athabascae, DNA microsatellites, genetic variation, genetic relatedness.

Vigilance and foraging patterns of American elk during the rut in habitats with and without predators

2003 ◽  
Vol 81 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Jerry O Wolff ◽  
Toni Van Horn
Keyword(s):  
Cervus Elaphus ◽  
National Park ◽  
Forest Cover ◽  
Hot Springs ◽  
Rocky Mountain ◽  
Predation Pressure ◽  
Risk Avoidance ◽  
Foraging Patterns ◽  
Survival And Reproduction ◽  
Free Environment

Animal behavior is often optimized as a trade-off between survival and reproduction. During the breeding season, mammals tend to maximize their reproductive effort within the constraints of predation pressure. When predation pressure is reduced, greater effort can be allocated to reproductive behavior and less to vigilance and predator avoidance. The objective of this study was to test the hypothesis that elk, Cervus elaphus, in Yellowstone National Park (YNP), with predators, would spend more time in vigilance and risk-avoidance behavior than would elk in Rocky Mountain National Park (RMNP), a predator-free environment. We further predicted that elk at Mammoth Hot Springs (MAM) in YNP would behave similarly to those at RMNP because predators were absent in that area of the park. Cow elk in YNP spent more time in vigilance and less in foraging during activity periods than did cows in RMNP or MAM. Also, elk in YNP retreated to forest cover during the midday inactive period, whereas elk in RMNP and MAM remained in open habitat. Vigilance was not correlated with group size at either site. Cows with calves spent more time in vigilance and less in foraging than did cows without calves in RMNP and YNP. Bull elk spent most of their time in courtship at all sites, but foraged more at RMNP than in YNP or MAM. Mean harem sizes were similar among the three sites: 17.0 in RMNP, 15.7 in YNP, and 19.0 in MAM. The proportion of cows with calves was significantly lower in the area with predators, YNP (0.10), than in the predator-free areas (0.24 in RMNP and 0.37 in MAM), probably because of greater calf mortality in YNP. Elk in YNP behaved in accordance with a predation risk, whereas those in RMNP and MAM showed less vigilance behavior.

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.

scholarly journals Table scraps: inter-trophic food provisioning by pumas

2012 ◽  
Vol 8 (5) ◽  
pp. 776-779 ◽  
Author(s):  
L. Mark Elbroch ◽  
Heiko U. Wittmer
Keyword(s):  
Canis Lupus ◽  
National Park ◽  
Puma Concolor ◽  
Large Carnivores ◽  
Food Provisioning ◽  
Ecological Functions ◽  
Natural Systems ◽  
Food Subsidies ◽  
Vultur Gryphus ◽  
Natural Communities

Large carnivores perform keystone ecological functions through direct predation, or indirectly, through food subsidies to scavengers or trophic cascades driven by their influence on the distributions of their prey. Pumas ( Puma concolor ) are an elusive, cryptic species difficult to study and little is known about their inter-trophic-level interactions in natural communities. Using new GPS technology, we discovered that pumas in Patagonia provided 232 ± 31 kg of edible meat/month/100 km 2 to near-threatened Andean condors ( Vultur gryphus ) and other members of a diverse scavenger community. This is up to 3.1 times the contributions by wolves ( Canis lupus ) to communities in Yellowstone National Park, USA, and highlights the keystone role large, solitary felids play in natural systems. These findings are more pertinent than ever, for managers increasingly advocate controlling pumas and other large felids to bolster prey populations and mitigate concerns over human and livestock safety, without a full understanding of the potential ecological consequences of their actions.

scholarly journals Relationships between Climatic Variation and Grassland Biomass on the Northern Range of Yellowstone National Park

1987 ◽  
Vol 11 ◽  
pp. 153-159
Author(s):  
Mark Boyce ◽  
Evelyn Merrill ◽  
Ronald Marrs
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Population Characteristics ◽  
Plant Production ◽  
Field Surveys ◽  
Fat Reserves ◽  
Survival And Reproduction ◽  
Summer Range ◽  
Vegetation Maps ◽  
Landsat Satellite

Summer range is not thought to be limiting to elk because abundant, high quality forage is available whereas a shortage of forage usually exists on elk winter ranges. Nevertheless, summer nutrition and fat reserves acquired on summer ranges influence growth, survival and reproduction of ungulates (Klein 1965, Verme 1963, 1965, Julander et al. 1961). The enormous area of summer range for the Northern Yellowstone elk herd renders detailed field surveys impractical. This study was initiated to evaluate the feasibility of using LANDSAT satellite imagery to (1) characterize vegetation communities on summer range from LANDSAT multispectral scanner (MSS) data and digitized vegetation maps of Yellowstone National Park, (2) predict plant production within grassland types and (3) correlate elk population characteristics with fluctuations in plant production and weather.

scholarly journals Experts correctly describe demography associated with historical decline of the endangered Indiana bat, but not recent period of stationarity

2017 ◽  
Author(s):  
Wayne Thogmartin ◽  
Carol Sanders-Reed ◽  
Jennifer Szymanski ◽  
Lori Pruitt ◽  
Michael Runge
Keyword(s):  
Population Decline ◽  
Survival Rates ◽  
Clear Understanding ◽  
Myotis Sodalis ◽  
Indiana Bat ◽  
White Nose Syndrome ◽  
Demographic Behavior ◽  
Pup Survival ◽  
Survival And Reproduction ◽  
Reproductive Rates

Demographic characteristics of bats are often insufficiently described for modeling populations. In data poor situations, experts are often relied upon for characterizing ecological systems. In concert with the development of a matrix model describing Indiana bat (Myotis sodalis) demography, we elicited estimates for parameterizing this model from 12 experts. We conducted this elicitation in two stages, requesting expert values for 12 demographic rates. These rates were adult and juvenile seasonal (winter, summer, fall) survival rates, pup survival in fall, and propensity and success at breeding. Experts were most in agreement about adult fall survival (3% Coefficient of Variation) and least in agreement about propensity of juveniles to breed (37% CV). The experts showed greater concordance for adult ( mean CV, adult = 6.2%) than for juvenile parameters ( mean CV, juvenile = 16.4%), and slightly more agreement for survival (mean CV, survival = 9.8%) compared to reproductive rates ( mean CV, reproduction = 15.1%). However, survival and reproduction were negatively and positively biased, respectively, relative to a stationary dynamic. Despite the species exhibiting near stationary dynamics for two decades prior to the onset of a potential extinction-causing agent, white-nose syndrome, expert estimates indicated a population decline of -11% per year (95% CI = -2%, -20%); quasi-extinction was predicted within a century ( mean = 61 years to QE, range = 32, 97) by 10 of the 12 experts. Were we to use these expert estimates in our modeling efforts, we would have errantly trained our models to a rapidly declining demography asymptomatic of recent demographic behavior. While experts are sometimes the only source of information, a clear understanding of the temporal and spatial context of the information being elicited is necessary to guard against wayward predictions.

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