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 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.

Limitation and regulation of moose populations: the role of predation

1994 ◽  
Vol 72 (12) ◽  
pp. 2071-2077 ◽  
Author(s):  
Victor Van Ballenberghe ◽  
Warren B. Ballard
Keyword(s):  
North America ◽  
Empirical Evidence ◽  
Canis Lupus ◽  
Ursus Arctos ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Human Influence ◽  
Density Reduction ◽  
Sound Management

An improved understanding of factors limiting and regulating ungulate populations is vital for sound management, especially with regard to controversial factors like predation. We examine the claim that evidence is weak for predation acting as a major factor limiting or regulating moose (Alces alces) populations in North America. Biologists have been inconsistent in defining limitation and regulation, have used these terms interchangeably, and have incorrectly assumed that major limiting factors regulate moose density. Empirical evidence indicates that many moose populations preyed on by both bears (Ursus arctos and U. americana) and wolves (Canis lupus) persist at densities much lower than K/2 when human influence is minimal. Under these conditions, reduction of predator numbers often results in increased moose density. Reduction of moose from high densities with predators held constant results in inversely density-dependent (anti-regulatory) predation and low moose densities for prolonged periods. In ecosystems lacking bears, or in those subject to substantial human influence, predation may not be a major limiting factor, may vary greatly in its impact, and may be overshadowed by interactions among moose, forage, weather, and hunting that primarily determine moose density. We conclude that in naturally regulated ecosystems, predation on moose by bears and wolves is often limiting and may be regulating, and we identify the conditions necessary for this to occur.

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.

Wolf predation in a multiple-ungulate system in northern British Columbia

1998 ◽  
Vol 76 (8) ◽  
pp. 1551-1569 ◽  
Author(s):  
A T Bergerud ◽  
J P Elliott
Keyword(s):  
British Columbia ◽  
Canis Lupus ◽  
Birth Rate ◽  
Rangifer Tarandus ◽  
Adult Mortality ◽  
Recruitment Rate ◽  
Wolf Predation ◽  
Rate Of Increase ◽  
Ovis Dalli ◽  
Hunting Statistics

Caribou (Rangifer tarandus), elk (Cervus canadensis), moose (Alces alces), and Stone's sheep (Ovis dalli stonei) were either decreasing or stable in numbers in two areas in northeastern British Columbia in 1981-1982, prior to reductions in wolf (Canis lupus) numbers. Following the reduction of wolf numbers, recruitment improved 2-5 times for all four species, and all populations increased, based on either hunting statistics, census results, and (or) recruitments greater than 24 offspring at 9 months of age per 100 females. Recruitment of offspring at 9 months of age, when regressed against wolf numbers, declined with decelerating slopes for all four species. This inverse functional response is hypothesized to result from the preparturient spacing of females to reduce predation risk, and in this regard moose seem the least secure and sheep the most effectively spaced. For the four species, mean recruitment at 9 months of age that balanced adult mortality and provided a finite rate of increase of 1.00 was 24.16 ± 0.91 offspring/100 females (n = 11, coefficient of variation = 12.5%). The predicted recruitment rate for all four species in the absence of wolves was 53-57 offspring/100 females. But the birth rate of moose was much higher than those of the other species, indicating greater loss to other factors of which bear predation may be the greatest. Following wolf reductions of 60-86% of entire travelling packs, the wolves quickly recolonized the removal zones, with rates of increase ranging from 1.5 to 5.6.

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 Elephant population growth in Kruger National Park, South Africa, under a landscape management approach

Koedoe ◽  
2017 ◽  
Vol 59 (1) ◽  
Author(s):  
Sam M. Ferreira ◽  
Cathy Greaver ◽  
Chenay Simms
Keyword(s):  
Population Growth ◽  
National Parks ◽  
National Park ◽  
Landscape Management ◽  
Aerial Survey ◽  
Kruger National Park ◽  
Management Approach ◽  
Intensive Management ◽  
Ecological Processes ◽  
Management Interventions

South African National Parks (SANParks) manage landscapes rather than numbers of elephants (Loxodonta africana) to mitigate the effects that elephants may have on biodiversity, tourism and stakeholder conservation values associated with protected areas. This management philosophy imposes spatial variability of critical resources on elephants. Restoration of such ecological processes through less intensive management predicts a reduction in population growth rates from the eras of intensive management. We collated aerial survey data since 1995 and conducted an aerial total count using a helicopter observation platform during 2015. A minimum of 17 086 elephants were resident in the Kruger National Park (KNP) in 2015, growing at 4.2% per annum over the last generation of elephants (i.e. 12 years), compared to 6.5% annual population growth noted during the intensive management era ending in 1994. This may come from responses of elephants to density and environmental factors manifested through reduced birth rates and increased mortality rates. Authorities should continue to evaluate the demographic responses of elephants to landscape scale interventions directed at restoring the limitation of spatial variance in resource distribution on elephant spatiotemporal dynamics and the consequences that may have for other conservation values.Conservation implications: Conservation managers should continue with surveying elephants in a way that allows the extraction of key variables. Such variables should focus on measures that reflect on how theory predicts elephants should respond to management interventions.

scholarly journals Fertilization the Omission One Test as Determination Limiting Factors for Maize Biomass (Zea mays L.)

2021 ◽  
Vol 4 (2) ◽  
pp. 94-105
Author(s):  
Koko Tampubolon ◽  
Bagus Fitra Azmi ◽  
Perdana Andriano Tamba ◽  
Ayu Widya Lestari ◽  
Kamaruddin Kamaruddin ◽  
...  
Keyword(s):  
Plant Height ◽  
Leaf Growth ◽  
Block Design ◽  
Relative Yield ◽  
Animal Husbandry ◽  
Dry Weight ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Test Technique ◽  
The Impact

Introduction: The research was aimed to obtain information on the impact of omission one test fertilization as a determination limiting factors for the growth and biomass of maize in variety Bonanza F1. Materials and Methods: The research was located in the experimental field, Faculty of Agriculture and Animal Husbandry, Universitas Tjut Nyak Dhien, Medan from December 2020 until February 2021. The research was applied by Randomized Block Design in non-factorial through fertilization of omission one test that has been converted (urea : SP-36 : KCl = 0.75 : 0.50 : 0.125 g polybag-1). The treatment of this research include P0 = non-fertilization; P1= N+P+K; P2= P+K; P3= N+K; P4= N+P using three replications. The parameters include plant height, leaf growth, total fresh weight, total dry weight, and the percentage of relative yield then processed using ANOVA and continued with DMRT at 5% ± standard error with SPSS v.20 software. Results: Informed that the omission one test technique significantly improved all the characteristics of maize in the variety Bonanza F1. The highest increase in plant height was found in the N+P of 83.65%, meanwhile, the highest leaf and biomass growth characters were found in N+P+K, ranged of 50.00 to 177.81% and 487.60 to 507.37%, respectively. It was obtained that the limiting factor for the maize growth in variety Bonanza F1 was found in the un-fertilization of nitrogen.

scholarly journals APLIKASI SIG UNTUK PENETAPAN KESESUAIAN WILAYAH PENERAPAN MEKANISASI PERTANIAN TANAMAN PANGAN

2016 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Mubekti Mubekti
Keyword(s):  
Remote Sensing ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Physical Parameters ◽  
Know How ◽  
Agricultural Mechanization ◽  
Preliminary Research

The study is the preliminary research aiming to apply the usefulness of the GISsystem for classifying suitability of region to the agricultural mechanization. Simplebasic theory of GIS and classification of agricultural mechanization were presented.Nine physical and non-physical parameters as limiting factors were defined and aweight of each parameter was calculated in order to know how far its effect to theagricultural mechanization practice. Data coming from several types, ie: numeric,vector and remote sensing (raster) were prepared to support the process. Twoordoes consisting of five classes were employed to extract suitability classificationof each District in Jawa Barat dan Banten Province. The results show that tendistricts are classified into suitable for applying agricultural mechanization, and therest ten districts are classified into not suitable. Depending on the dynamic characterof limiting factor, suitability class would possibly change along the time. Saveralconclusions and advices for improving research are given.

scholarly journals Principle of Limiting Factors-Driven Piecewise Population Growth Model I: Qualitative Exploration and Study Cases on Continuous-Time Dynamics

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Héctor A. Echavarria-Heras ◽  
Cecilia Leal-Ramírez ◽  
Guillermo Gómez ◽  
Elia Montiel-Arzate
Keyword(s):  
Population Growth ◽  
Growth Model ◽  
Continuous Time ◽  
Extreme Values ◽  
Logistic Map ◽  
Phase Region ◽  
Limiting Factors ◽  
Time Dynamics ◽  
The Law ◽  
Global Trajectory

We examine the comportment of the global trajectory of a piecewisely conceived single species population growth model. Formulation relies on what we develop as the principle of limiting factors for population growth, adapted from the law of the minimum of Liebig and the law of the tolerance of Shelford. The ensuing paradigm sets natality and mortality rates to express through extreme values of population growth determining factor. Dynamics through time occur over different growth phases. Transition points are interpreted as thresholds of viability, starvation, and intraspecific competition. In this delivery, we focus on the qualitative study of the global trajectory expressed on continuous time and on exploring the feasibility of analytical results against data on populations growing under experimental or natural conditions. All study cases sustained fittings of high reproducibility both at empirical and interpretative slants. Possible phase configurations include regimes with multiple stable equilibria, sigmoidal growth, extinction, or stationarity. Here, we also outline that the associating discrete-time piecewise model composes the logistic map applied over a particular region of the phase configuration. Preliminary exploratory analysis suggests that the logistic map’s chaos onset could surpass once the orbit enters a contiguous phase region.

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