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.

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.

scholarly journals Predation pressure of the grey wolf (Canis lupus L. 1758) on wild, domestic and companion animals in Poland

2021 ◽  
Vol 77 (10) ◽  
pp. 6579-2021
Author(s):  
KATARZYNA DZIKI-MICHALSKA ◽  
KATARZYNA TAJCHMAN
Keyword(s):  
Canis Lupus ◽  
Companion Animals ◽  
Companion Animal ◽  
Predation Pressure ◽  
Protection System ◽  
Animal Population ◽  
Grey Wolf ◽  
Wolf Population ◽  
Wild Ungulate ◽  
The Relationship

The aim of this study was to determine the predation pressure of the grey wolf (Canis lupus) on wild ungulate populations and the relationship between the size of the grey wolf population and the number of confirmed kills of livestock and companion animals in Poland over eight hunting seasons from 2011/2012 to 2018/2019. There is a positive and complete relationship between the increasing wolf population and the number of confirmed deer kills. The size of the wolf population in Poland was compared to the size of domestic and companion animal population and the number of specimens that fell prey to the grey wolf. It was demonstrated that as the wolf population in Poland increases, the number of confirmed kills of farm and companion animals rises. It seems rational to take steps aimed at mitigating this problem as soon as possible. It is necessary to consider implementation of an integrated protection system that involves culling and employing available methods to deter wolves from attacking grazing herds.

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.

Factors affecting gray wolf (Canis lupus) encounter rate with elk (Cervus elaphus) in Yellowstone National Park

2018 ◽  
Vol 96 (9) ◽  
pp. 1032-1042 ◽  
Author(s):  
H.W. Martin ◽  
L.D. Mech ◽  
J. Fieberg ◽  
M.C. Metz ◽  
D.R. MacNulty ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Canis Lupus ◽  
Yellowstone National Park ◽  
Snow Depth ◽  
National Park ◽  
Encounter Rate ◽  
Encounter Rates ◽  
Hunting Success ◽  
Kill Rate ◽  
The Relationship

Despite encounter rates being a key component of kill rate, few studies of large carnivore predation have quantified encounter rates with prey, the factors that influence them, and the relationship between encounter rate and kill rate. The study’s primary motivation was to determine the relationship between prey density and encounter rate in understanding the mechanism behind the functional response. Elk (Cervus elaphus Linnaeus, 1758) population decline and variable weather in northern Yellowstone National Park provided an opportunity to examine how these factors influenced wolf (Canis lupus Linnaeus, 1758) encounter rates with elk. We explored how factors associated with wolf kill rate and encounter rate in other systems (season, elk density, elk group density, average elk group size, snow depth, wolf pack size, and territory size) influenced wolf–elk encounter rate in Yellowstone National Park. Elk density was the only factor significantly correlated with wolf–elk encounter rate, and we found a nonlinear density-dependent relationship that may be a mechanism for a functional response in this system. Encounter rate was correlated with number of elk killed during early winter but not late winter. Weak effects of snow depth and elk group size on encounter rate suggest that these factors influence kill rate via hunting success because kill rate is the product of hunting success and encounter rate.

scholarly journals The problems with pooling poop: confronting sampling method biases in wolf (Canis lupus) diet studies

2017 ◽  
Vol 95 (11) ◽  
pp. 843-851 ◽  
Author(s):  
T.D. Gable ◽  
S.K. Windels ◽  
J.G. Bruggink
Keyword(s):  
Canis Lupus ◽  
Temporal Variability ◽  
National Park ◽  
Sampling Method ◽  
Wolf Population ◽  
Scat Analysis ◽  
Collection Method ◽  
Age Class ◽  
Voyageurs National Park ◽  
Collection Methods

Wolf (Canis lupus L., 1758) diet is commonly estimated via scat analysis. Several researchers have concluded that scat collection method can bias diet estimates, but none of these studies properly accounted for interpack, age class, and temporal variability, all of which could bias diet estimates. We tested whether different scat collection methods yielded different wolf diet estimates after accounting for these other potential biases. We collected scats (n = 2406) monthly from four packs via three scat collection methods (at home sites, at clusters of GPS locations, and opportunistically) in and adjacent to Voyageurs National Park, Minnesota, USA, during April–October 2015. Diet estimates were not affected by scat collection method but did vary temporally, among packs, and by age class. To more accurately estimate wolf population diets, researchers should collect 10–20 adult scats/pack per month from home sites and (or) opportunistically from packs that are representative of the population of interest. Doing so will minimize the potential biases associated with temporal, interpack, and age-class variability.

scholarly journals Reproduction and Mortality of the High Arctic Wolf, Canis lupus arctos, in Northeast Greenland, 1978-1998

2008 ◽  
Vol 122 (2) ◽  
pp. 142 ◽  
Author(s):  
Ulf Marquard-Petersen
Keyword(s):  
Spatial Analysis ◽  
North America ◽  
Litter Size ◽  
Canis Lupus ◽  
National Park ◽  
American Studies ◽  
High Arctic ◽  
Wolf Population ◽  
Temporal And Spatial ◽  
Direct Counts

Reproduction and mortality of the High Arctic Wolf (Canis lupus arctos) in northeast Greenland were investigated through a temporal and spatial analysis of data on litter sizes from direct counts of pups during 21 years (1978-1998). A minimum of 22 pups were produced in a total of six areas. Overall mean litter size was 2.0 pups/litter. This was the lowest mean litter size recorded for Wolves in North America through observations of pups in summer and was probably related to low availability and vulnerability of ungulate prey. Pack size and litter size were very strongly positively correlated. Large packs (4-7 adults) produced significantly more pups than smaller packs. Mean maximum litter size from 17 North American studies employing similar methods, suggested that maximum productivity of wolves in Greenland was 58% below that of wolves elsewhere. The number of Wolf pups born in North America was negatively correlated with increasing latitude. Eight mortalities were identified and were predominantly caused by humans despite the fact that this Wolf population inhabits a national park with year-round protection.

Responses of bison on their calving grounds to predation by wolves in Wood Buffalo National Park

1987 ◽  
Vol 65 (8) ◽  
pp. 2072-2078 ◽  
Author(s):  
L. N. Carbyn ◽  
T. Trottier
Keyword(s):  
National Park ◽  
Physical Contact ◽  
Wolf Predation ◽  
Hunting Strategies ◽  
Cow Calf ◽  
Wood Buffalo National Park ◽  
The Relationship

Bison-wolf interactions were observed from a tower located in the centre of a meadow in Wood Buffalo National Park, Alberta, Canada, from 10 May to 9 September 1980. Special attention was directed to the relationship between bison cow-calf interactions, calf pod formations, and wolf predation attempts. Pod formation began in May and peaked in June. During 102 days in the field, 166 encounters between wolves and bison were observed, of which 51 involved a single wolf interacting with bison. In the main, single wolves watched bison (23% of observations), trailed without follow-up (14%), trailed with follow-up (27%), or harassed them without making physical contact (34%). Only rarely (2% of the observations) did they attack. The remaining 115 encounters involved a pack of wolves (two or more individuals). The majority of them involved trailing with follow-up (26%) or harassment (48%), and rushing with physical contact (13%). Wolves, especially those in packs, preferentially attacked bison herds with calves over herds without calves. Single wolves were more likely than wolves in packs to attack herds of bulls only (34 vs. 5% of such encounters). Strategies used by bison in defence of their calves were recorded along with the hunting strategies employed by wolves.

scholarly journals Demographic Patterns and Limitation of Grey Wolves, Canis lupus, in and Near Pukaskwa National Park, Ontario

2004 ◽  
Vol 118 (1) ◽  
pp. 95 ◽  
Author(s):  
S. Anne Forshner ◽  
Paul C. Paquet ◽  
Frank G. M. Burrows ◽  
Graham K. Neale ◽  
Keith D. Wade ◽  
...  
Keyword(s):  
Population Growth ◽  
Canis Lupus ◽  
National Park ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Wolf Population ◽  
Rate Of Increase ◽  
Consumption Rates ◽  
Pukaskwa National Park ◽  
Demographic Patterns

In response to concern regarding the growth and long-term viability of the wolf population in and near Pukaskwa National Park, a study of demographic patterns and limitation of radio-collared wolves (Canis lupus) was completed between 1994 and 1998. The mean annual finite rate of increase (0.96) suggested that population growth of wolves was limited and declining slightly. Small pack sizes, high cumulative mortality, and low reproductive success also suggested a declining population. Two limiting factors, ungulate biomass and human-caused mortality, were examined to determine the importance of each in limiting the population growth of wolves. Ungulate biomass was involved because occurrence of natural-caused mortality was high (9 of 17 wolves) compared with other studies. In addition, consumption rates were low and similar to other studies where starvation and other signs of malnutrition were noted. Further, Moose densities in the study area were low to moderate and below thresholds indicating nutritional stress for wolves. Occurrence of human-caused mortality was high (8 of 17 wolves) suggesting that it was also an important limiting factor, particularly given the low availability of ungulate biomass and reproduction noted in this study. Based on present demographic patterns, ungulate biomass, and human-caused mortality, the wolf population likely will remain at present low densities or continue to decline.

scholarly journals Predator-Prey Dynamics of Intra-Host Simian Immunodeficiency Virus Evolution Within the Untreated Host

2021 ◽  
Vol 12 ◽  
Author(s):  
Brittany Rife Magalis ◽  
Patrick Autissier ◽  
Kenneth C. Williams ◽  
Xinguang Chen ◽  
Cameron Browne ◽  
...  
Keyword(s):  
Population Size ◽  
Disease Progression ◽  
Large Scale ◽  
Immune Cell ◽  
Sequence Data ◽  
Viral Population ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Temporal Sampling ◽  
The Relationship

The dynamic nature of the SIV population during disease progression in the SIV/macaque model of AIDS and the factors responsible for its behavior have not been documented, largely owing to the lack of sufficient spatial and temporal sampling of both viral and host data from SIV-infected animals. In this study, we detail Bayesian coalescent inference of the changing collective intra-host viral effective population size (Ne) from various tissues over the course of infection and its relationship with what we demonstrate is a continuously changing immune cell repertoire within the blood. Although the relative contribution of these factors varied among hosts and time points, the adaptive immune response best explained the overall periodic dynamic behavior of the effective virus population. Data exposing the nature of the relationship between the virus and immune cell populations revealed the plausibility of an eco-evolutionary mathematical model, which was able to mimic the large-scale oscillations in Ne through virus escape from relatively few, early immunodominant responses, followed by slower escape from several subdominant and weakened immune populations. The results of this study suggest that SIV diversity within the untreated host is governed by a predator-prey relationship, wherein differing phases of infection are the result of adaptation in response to varying immune responses. Previous investigations into viral population dynamics using sequence data have focused on single estimates of the effective viral population size (Ne) or point estimates over sparse sampling data to provide insight into the precise impact of immune selection on virus adaptive behavior. Herein, we describe the use of the coalescent phylogenetic frame- work to estimate the relative changes in Ne over time in order to quantify the relationship with empirical data on the dynamic immune composition of the host. This relationship has allowed us to expand on earlier simulations to build a predator-prey model that explains the deterministic behavior of the virus over the course of disease progression. We show that sequential viral adaptation can occur in response to phases of varying immune pressure, providing a broader picture of the viral response throughout the entire course of progression to AIDS.

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