Comparaison de quatre méthodes statistiques pour estimer les niveaux de population du lièvre d'Amérique, Lepus americanus

1975 ◽  
Vol 53 (5) ◽  
pp. 657-660
Author(s):  
Jean-Clet Gendron ◽  
Jean-Marie Bergeron
Keyword(s):  
Linear Regression ◽  
Population Density ◽  
Lepus Americanus ◽  
Snowshoe Hare

Our FORTRAN IV program allowed us to estimate (P > 99%) the population density of the snowshoe hare following the method of linear regression and those of Schnabel and Hayne. This latter method represents the first attempt to estimate the population levels of this rodent. The Lincoln index is the least reliable of the four tests.

scholarly journals Estimation of snowshoe hare population density from turd transects

1987 ◽  
Vol 65 (3) ◽  
pp. 565-567 ◽  
Author(s):  
Charles J. Krebs ◽  
B. Scott Gilbert ◽  
S. Boutin ◽  
R. Boonstra
Keyword(s):  
Population Density ◽  
Fecal Pellet ◽  
Accurate Method ◽  
Yukon Territory ◽  
Lepus Americanus ◽  
Snowshoe Hare ◽  
Model Average ◽  
Pellet Counts ◽  
Hare Population ◽  
Kluane Lake

We counted the number of snowshoe hare (Lepus americanus) fecal pellets on 50 quadrats of 0.155 m2 on each of six areas near Kluane Lake, Yukon Territory, once a year from 1977 to 1983. On four of these areas we livetrapped hares once a month and estimated population density from the Jolly–Seber model. Average hare density for the year was linearly related to fecal pellet counts (r = 0.94) over the range 0–10 hares/ha. Mean turd counts also are related to the variance of these counts by Taylor's power law with exponent 1.30, indicating a clumped pattern in turd deposition. Fecal pellet counts provide a quick and accurate method for snowshoe hare censuses on an extensive scale.

scholarly journals Estimating snowshoe hare population density from pellet plots: a further evaluation

2001 ◽  
Vol 79 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Charles J Krebs ◽  
Rudy Boonstra ◽  
Vilis Nams ◽  
Mark O'Donoghue ◽  
Karen E Hodges ◽  
...  
Keyword(s):  
Population Density ◽  
Strong Relationship ◽  
Geographic Range ◽  
Lepus Americanus ◽  
Snowshoe Hare ◽  
Fecal Pellets ◽  
Density Estimates ◽  
Snowshoe Hares ◽  
Pellet Counts ◽  
Hare Population

We counted fecal pellets of snowshoe hares (Lepus americanus) once a year in 10 areas in the southwestern Yukon from 1987 to 1996. Pellets in eighty 0.155-m2 quadrats were counted and cleared each June on all areas, and we correlated these counts with estimates of absolute hare density obtained by intensive mark–recapture methods in the same areas. There is a strong relationship between pellet counts and population density (r = 0.76), and we present a predictive log–log regression to quantify this relationship, which improves on our previously published 1987 regression, particularly at low hare densities. The precision of density estimates can be improved most easily by increasing the number of sets of quadrats in an area (one set = 80 plots), rather than increasing the number of plots counted within one set. The most important question remaining concerns the generality of this relationship for snowshoe hares living in other habitats in the eastern and southern portions of their geographic range.

How do population density and food supply influence social behaviour in the snowshoe hare (Lepus americanus)?

1993 ◽  
Vol 71 (6) ◽  
pp. 1084-1089 ◽  
Author(s):  
Jean Ferron
Keyword(s):  
Population Density ◽  
Breeding Season ◽  
Group Size ◽  
Food Availability ◽  
Social Behaviour ◽  
Lepus Americanus ◽  
Snowshoe Hare ◽  
Agonistic Behaviour ◽  
Nonbreeding Season ◽  
The Impact

The influence of population density and food on the social behaviour of the snowshoe hare (Lepus americanus) was studied in an outdoor enclosure. The year was divided into two periods: the nonbreeding season (October to March) and the breeding season (April to August). During each period, data on social interactions were recorded for groups of 4, 6, 8, and 10 animals, with three different sets of animals for each group size. Agonistic behaviour characterized social encounters between hares year-round. During the nonbreeding season, there was a significant correlation between agonistic behaviour and group size for females only. During the breeding season, the rate of interaction was lower and agonistic behaviour was significantly and negatively correlated with group size for males only. Two-way ANOVA of total agonistic behaviour revealed that group size and sex interacted significantly only during the nonbreeding season. The different categories of agonistic behaviour (aggression, threat, and taking the place of another animal) were also analysed separately. The distribution of aggression within each of the experimental groups indicated that the two top-ranking animals were generally males and that they initiated most of the aggressive encounters. Another experiment with restricted food availability was conducted to study the impact of limited resources on agonistic behaviour. Hares were significantly more aggressive when food was restricted than when food was available ad libitum. It thus appears that food availability has a stronger influence on social behaviour than does hare density.

scholarly journals Northern Goshawk, Accipiter gentilis, Exploits a Beagle Hound, Canis familiaris, as a "Beater" to Catch a Snowshoe Hare, Lepus americanus

2007 ◽  
Vol 121 (3) ◽  
pp. 329
Author(s):  
John T. Neville
Keyword(s):  
Canis Familiaris ◽  
First Record ◽  
Lepus Americanus ◽  
Accipiter Gentilis ◽  
Snowshoe Hare ◽  
Northern Goshawk

During a winter Snowshoe Hare (Lepus americanus) hunt with a beagle hound (Canis familiaris), I observed an adult Northern Goshawk (Accipiter gentilis) exploiting the running, barking hound as a “beater” and use strategic locations for attacks. The hawk made three attacks on a hare being pursued by the hound, and subsequently caught and killed it. To my knowledge, this report represents the first record of a Northern Goshawk using this behavior to capture prey.

scholarly journals Self-Reinforcing Processes Governing Urban Sprawl in Belgium: Evidence over Six Decades

2020 ◽  
Vol 12 (10) ◽  
pp. 4097 ◽  
Author(s):  
Ahmed Mustafa ◽  
Jacques Teller
Keyword(s):  
Linear Regression ◽  
Population Density ◽  
Urban Sprawl ◽  
Urban Dispersion ◽  
Dispersion Degree ◽  
Dispersion Patterns ◽  
Study Country ◽  
Per Capita ◽  
Different Levels ◽  
Over Time

Urban sprawl is widely acknowledged as an environmental and socio-economic challenge worldwide. This study examines urban sprawl in Belgium over six decades from 1950 to 2010. We assume that sprawl is a self-reinforcing process, i.e., sprawl is fueling further sprawl over time. The main objective of this study is to examine this assumption. We measure urban sprawl at four different levels in this study: country, regions, municipalities, and 1-km2 cells. Three sprawl indices are employed: the degree of urban dispersion, degree of urban permeation of the landscape, and built-up land uptake per capita. These three indices consider both the growth of built-up areas and population density to measure the magnitude of sprawl. The drivers of urban sprawl have been analyzed at a 1-km2 level. The examined drivers are previous urban dispersion patterns, distance to urban cores, elevation, and slope degree by means of linear regression. Urban sprawl significantly increased between 1950 and 1980, whereas its increase was more moderate between 1980 and 2010. Urban dispersion and permeation strongly affect the Brussels and Flanders regions. The results show that the increase in the degree of dispersion is locally driven by previous values of dispersion; i.e., it provides an adequate milieu for further dispersion. Therefore, our conclusion is that urban sprawl in Belgium tends to be a self-reinforcing process.

The hidden history of the snowshoe hare,Lepus americanus: extensive mitochondrial DNA introgression inferred from multilocus genetic variation

2014 ◽  
Vol 23 (18) ◽  
pp. 4617-4630 ◽  
Author(s):  
José Melo-Ferreira ◽  
Fernando A. Seixas ◽  
Ellen Cheng ◽  
L. Scott Mills ◽  
Paulo C. Alves
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Lepus Americanus ◽  
Snowshoe Hare ◽  
History Of

Clear-cutting and regeneration practices in Quebec boreal balsam fir forest: effects on snowshoe hare

2001 ◽  
Vol 31 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Sonia de Bellefeuille ◽  
Louis Bélanger ◽  
Jean Huot ◽  
Agathe Cimon
Keyword(s):  
Boreal Forest ◽  
Natural Regeneration ◽  
Lepus Americanus ◽  
Seedling Stage ◽  
Snowshoe Hare ◽  
Short Term ◽  
Clear Cut ◽  
Clear Cutting ◽  
Term Basis ◽  
Protective Cover

We compared utilization by the snowshoe hare (Lepus americanus Erxleben) of recent clearcuts subjected to three regeneration scenarios commonly used in boreal forest: natural regeneration, plantation with herbicide release (glyphosate), and plantation with manual release (brushsaw). Refuges for snowshoe hare, on a landscape dominated by clearcuts, were also investigated. Colonization of regenerating sites by the hare comes late in the humid boreal forest because clear-cut stands take more than 10 years to reach the sapling stage. Our sites were in the seedling stage 7–9 years after cutting, and hares avoided them year round because of an inadequate protective cover. Therefore, regeneration treatments did not affect habitat use by the hare on a short-term basis. During the seedling stage, the snowshoe hare were found in the remaining forest which occupied at least 25% of the area of each home range. The preservation of residual forests is thus essential to maintain local populations on an area dominated by commercial clearcuts.

scholarly journals Patterns and potential drivers of intraspecific variability in the body elemental composition of a terrestrial consumer, the snowshoe hare (Lepus americanus)

2019 ◽  
Author(s):  
Matteo Rizzuto ◽  
Shawn J. Leroux ◽  
Eric Vander Wal ◽  
Yolanda F. Wiersma ◽  
Travis R. Heckford ◽  
...  
Keyword(s):  
Body Size ◽  
Chemical Composition ◽  
Intraspecific Variability ◽  
Lepus Americanus ◽  
The Body ◽  
Whole Body ◽  
Snowshoe Hare ◽  
Weak Relationship ◽  
Snowshoe Hares ◽  
P Content

AbstractIntraspecific variability in ecological traits is widespread in nature. Recent evidence, mostly from aquatic ecosystems, shows individuals differing at the most fundamental level, that of their chemical composition. Age, sex, or body size may be key drivers of intraspecific variability in the body concentrations of carbon (C), nitrogen (N), and phosphorus (P). However, we still have a rudimentary understanding of the patterns and drivers of intraspecific variability in chemical composition of terrestrial consumers, particularly vertebrates.Here, we investigate the whole-body chemical composition of snowshoe hare Lepus americanus, providing one of the few studies of patterns of stoichiometric variability and its potential drivers for a terrestrial vertebrate. Based on snowshoe hare ecology, we expected higher P and N concentrations in females, as well as in larger and older individuals.We obtained whole-body C, N, and P concentrations and C:N, C:P, N:P ratios from a sample of 50 snowshoe hares. We then used general linear models to test for evidence of a relationship between age, sex, or body size and stoichiometric variability in hares.We found considerable variation in the C, N, and P concentrations and elemental ratios within our sample. Contrary to our predictions, we found evidence of N content decreasing with age. As expected, we found evidence of P content increasing with body size. As well, we found no support for a relationship between sex and N or P content, nor for variability in C content and any of our predictor variables.Despite finding considerable stoichiometric variability in our sample, we found no substantial support for age, sex, or body size to relate to this variation. The weak relationship between body N concentration and age may suggest varying nutritional requirements of individuals at different ages. Conversely, P’s weak relationship to body size appears in line with recent evidence of the potential importance of P in terrestrial systems. Snowshoe hares are a keystone herbivore in the boreal forest of North America. The substantial stoichiometric variability we find in our sample could have important implications for nutrient dynamics in both boreal and adjacent ecosystems.

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