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Статті в журналах з теми "Ursus arcto"
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Pasitschniak-Arts, Maria. "Ursus arctos." Mammalian Species, no. 439 (April 23, 1993): 1. http://dx.doi.org/10.2307/3504138.
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Winer, J. N., B. Arzi, S. Döring, P. H. Kass, and F. J. M. Verstraete. "Dental and Temporomandibular Joint Pathology of the North American Brown Bear ( Ursus arctos horribilis , Ursus arctos middendorffi and Ursus arctos sitkensis )." Journal of Comparative Pathology 157, no. 2-3 (August 2017): 90–102. http://dx.doi.org/10.1016/j.jcpa.2017.06.006.
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Britton, Ann P., Julie Bidulka, Andrea Scouras, Helen Schwantje, and Tomy Joseph. "Fatal hepatic sarcocystosis in a free-ranging grizzly bear cub associated with Sarcocystis canis–like infection." Journal of Veterinary Diagnostic Investigation 31, no. 2 (January 30, 2019): 303–6. http://dx.doi.org/10.1177/1040638719826627.
Повний текст джерелаАнотація:
We describe herein fatal hepatic sarcocystosis in a free-ranging grizzly bear ( Ursus arctos horribilis) cub with apicomplexan infection of the liver and brain, both demonstrating 100% homology for Sarcocystis canis and S. arctosi. Fatal hepatic sarcocystosis in dogs has been etiologically associated with intrahepatic schizonts of S. canis. In black and polar bears, a S. canis–like organism produces schizonts in the liver and massive hepatic necrosis. Although intramuscular sarcocysts, taxa S. arctosi and S. ursusi, have been described in healthy brown and black bears, respectively, they have not been detected in bears with hepatic sarcocystosis, to our knowledge, and it is currently unknown whether bears represent an aberrant or intermediate host.
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De Torres Pérez-Hidalgo, Trinidad. "La región auditiva en los osos del pleistoceno europeo." Spanish Journal of Palaeontology 2, no. 1 (September 5, 2022): 41. http://dx.doi.org/10.7203/sjp.25214.
Повний текст джерелаАнотація:
Este trabajo trata de la descripción y comparación de las principales características morfológicas de la región auditiva de los grandes osos del Pleistoceno europeo: Ursus prearctos Boule, Ursus deningeri von Reichenau, Ursus spelaeus Rosenmüller-Heinroth y Ursus arctos Linneo. Además de una serie de diferencias morfológicas menores, de origen e importancia inciertos, las más importantes son: bulla tympánica con la cara ventral aplanada y septum indiviso sin septas en U. prearctos y U.arctos, mientras que en las especies espeloides, U. deningeri y fundamentalmente U. spelaeus, la cara ventral de la bulla es irregular y el septum está dividido por una septa bien marcada. Estas morfologías probablemente estén ligadas a una mayor capacidad de resonancia de la bulla. El petroso es relativamente mayor en U.prearctos y U. arctos que en U. deningeri y U. spelaeus.
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Elgmork, Kåre, and Even Tjørve. "Brown bear Ursus arctos scavenging patterns." Wildlife Biology 1, no. 1 (January 1995): 239–42. http://dx.doi.org/10.2981/wlb.1995.0029.
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Vougiouklakis, Theodore. "Fatal Brown Bear (Ursus arctos) Attack." American Journal of Forensic Medicine and Pathology 27, no. 3 (September 2006): 266–67. http://dx.doi.org/10.1097/01.paf.0000220930.00053.43.
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Seryodkin, Ivan V. "Daily movements of Brown bears (Ursus arctos) in Kamchatka and Sakhalin." Vestnik Tomskogo gosudarstvennogo universiteta. Biologiya, no. 49 (March 2020): 107–27. http://dx.doi.org/10.17223/19988591/49/6.
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Radisic, B., M. Sindicic, D. Huber, J. Kusak, T. Gomercic, D. Vnuk, D. Maticic, and A. Slavica. "Ovariectomy of a brown bear (Ursus arctos): a case report." Veterinární Medicína 55, No. 7 (August 17, 2010): 353–57. http://dx.doi.org/10.17221/2965-vetmed.
Повний текст джерелаАнотація:
Reproductive control is regularly implemented in bear facilities to prevent crowding of enclosures and surplus animals. Ovariectomy may represent an efficient method of sterilizing bears yet has not been reported in the literature. A 73 kg female brown bear, age two years and three months, was anesthetized for ovariectomy with tiletamin and zolazepam (Zoletil<sup>®</sup>, Virbac S.A., Carros Cedex, France) and medetomidin hydrochloride (Domitor<sup>®</sup>, Pfizer Animal Health, New York, USA). A 25 cm midline incision that extended from the umbilicus to the pubic brim was made. The suspensory ligament was stretched and blunt dissected so that ovaries in bursa were exposed on the surgical field. A "Figure 8" ligature was placed between two forcepses and a circumferential ligature was placed around proximal forceps at the ovarian pedicle. Another "Figure 8" ligature was placed between two forcepses and a circumferential ligature was placed around distal forceps at the cranial tip of the uterine horn. No surgical complications occurred, and no complications have transpired during the 12 month post-operative period.
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Yoon, Byung Il, Jung Keun Lee, Jin Hyun Kim, Nam Shik Shin, Soo Wahn Kwon, Gi Hwan Lee, and Dae Yong Kim. "Lymphosarcoma in a brown bear (Ursus arctos)." Journal of Veterinary Science 2, no. 2 (2001): 143. http://dx.doi.org/10.4142/jvs.2001.2.2.143.
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Laikre, Linda, Robert Andrén, Hans-Ove Larsson, and Nils Ryman. "Inbreeding depression in brown bear Ursus arctos." Biological Conservation 76, no. 1 (1996): 69–72. http://dx.doi.org/10.1016/0006-3207(95)00084-4.
Повний текст джерелаДисертації з теми "Ursus arcto"
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Klenzendorf, Sybille A. "Management of brown bears (Ursus arctos) in Europe." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36807.
Повний текст джерелаАнотація:
Successful conservation of brown bears (Ursus arctos) in Europe is associated with public acceptance of damages caused by bears. Recent increases in sheep depredation and beehive damage in central Austria resulted in the deaths of two bears there. Since bear numbers are low in most European populations, alternatives to the elimination of problem bears associated with damage incidents must be sought. The events described above led to the formation of the Bear Management Group responsible for designing a management plan for Austria that will outline procedures for dealing with bear damage and conservation strategies.
This study provides an overview of the magnitude and seasonal patterns of brown bear damage in Romania, Italy, Slovenia, Norway, Sweden, and Austria. It also illustrates how bears are managed in European countries by comparing different management strategies for dealing with brown bear damage, describing how bear management is organized, determining which organizations are involved, and explaining which duties these fulfill.
Bear damage data were obtained from interviews with wildlife managers, hunters, and farmers in Romania, Italy, Slovenia, Norway, Sweden, and Austria, and from official records of their bear management agencies. Most damage incidents involved sheep and beehives in all countries. All countries offered a more or less well functioning damage compensation program to farmers. Conservation success, especially for small bear populations, seemed to be related to a good compensation program and reducing damage to livestock and property. Possible improvements of management strategies to reduce damage and increase conservation success in theses countries were discussed
The second part of this study was the assessment of the organizational structure of different bear management programs in Europe. Brown bear management in Europe included a broad spectrum of goals, ranging from no protection, to regulated hunting, to total protection. In each country, different organizations were involved in bear management, including private and governmental organizations. For each study country, I outlined which organizations were involved in bear management, determined if a management plan existed,described if and how hunting and damage compensation were structured, explained how each country dealt with problem bears, and finally, detailed what kind of management problems each country encountered. I tried to find management patterns for bear management in Europe, including advantages and disadvantages of each approach and their effectiveness within the countries they were applied. Methods included a content analysis of interviews with wildlife managers, farmers, and local people in each country.Results showed that two general types of management approaches could be identified. Romania, Sweden and Southern Slovenia took a conservationist approach, which was characterized by economic use of their bear population. All of these countries had viable bear populations. Romania and Southern Slovenia included an additional characteristic of feeding bears, which could be viewed as a utilitarian management scheme. The second management approach, which was classified as the preservationist approach, was observed in Norway, Italy, Northern Slovenia, and Austria. This management strategy was characterized by year-long protection of bears, low population numbers, and no feeding of bears.
Further results of management differences in problem bear management, damage compensation, public education, and effectiveness of management approaches were summarized. The study provides a reference on bear management strategies in Europe.Master of Science
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Corradini, Andrea. "Ecological connectivity in the Alpine anthropic matrix. Natural reserves and corridors for the conservation of brown bear in the Alps (ABC - AlpBearConnect)." Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/321014.
Повний текст джерелаАнотація:
Large carnivores are among the most challenging species to conserve in our modern and crowded world. Having large spatial requirements and living in low density, they generally require wide and relatively undisturbed areas. In Europe, one of the most anthropized areas of the planet, these needs must be fulfilled in a complex human-dominated landscape. The reintroduced brown bear population living in the Central Alps represents one of the most emblematic examples of a constrained carnivore: despite a steady population increase in the first few years after reintroduction, the population did not substantially expand its range, nor has the Alpine-Dinaric metapopulation been reestablished as envisioned. Although humans have lived in the Alps for centuries, little is known about their impact on the bear population. In other environments humans are known to function as a “super-predator” by changing habitats, competing for space, consuming resources, and harvesting, which alters the ecological niche of animals, especially large carnivores. This dissertation aims to evaluate this phenomenon by assessing the effects of human disturbance on brown bears in the Alps. Anthropogenic disturbance is generally assessed by structural proxies, such as infrastructure and land use, which overlook the impact of human presence. In the first Chapter, we developed the Cumulative Outdoor activity Index (COI) to derive anthropogenic disturbance using crowdsourced data by Strava and validated it with ground truth observations derived from a local camera trapping survey. The intensity of COI provided an effective measure of functional anthropogenic disturbance, and it outperformed all commonly-used proxies of structural disturbance in predicting bear habitat use. When displacement is not an option because of habitat limitations and social mechanisms, bear mobility may clash with human activity. During the moments of lowest mobility, such as resting periods, animals have decreased ability to cope with risky situations, and therefore the selection of suitable resting areas is crucial for the long-term survival of individuals. In the second Chapter, we measured multi-scale response to risk perception (i.e., COI) and resource proximity using bedding sites by GPS radio-collared adult brown bears in the Alps. To map resources across the study area, we developed a GIS-database combining spatial and non-spatial ecological information to map fruit availability. We observed that bears apply a security-food trade-off strategy, avoiding functional anthropogenic disturbance while in proximity to resources. In the third Chapter, we explicitly tested the effect of an abrupt interruption of human mobility during COVID-19 lockdown on bears’ use of ecological corridors. Using bear occurrences reported to local authorities during the recent COVID-19 outbreak, we observed that bears used human-dominated areas more frequently, approached more intensively hot spots for road crossing network, and used areas further from the population core areas more often than previous years, suggesting that connectivity increased with reduced human mobility. In a comparatively human-free system, for the fourth Chapter we used longitudinal morphometric data to analyze drivers of changes in body mass as part of an international collaboration with biologists studying the grizzly bear in the Greater Yellowstone Ecosystem. Specifically, we analyzed changes in lean body mass and fat percentage during years of major ecosystem perturbations. We observed that individual lean body mass during the last two decades was primarily associated with population density, but not body fat percentage, showing density-dependent factors. Our combined findings (Chapters 1-3) showed that brown bears have to adapt their space use, movement, and resource proximity as a result of functional anthropogenic disturbance. In Chapter 4 we explored one effect of unconstrained bear space use on individuals, as manifested through density-dependent effects on body size. In the Alps, however, we found multiple instances of the human-super predator outcompeting bears so as to make density-dependent effects likely less significant as compared to human-caused mortality. These effects could occur in a variety of socio-ecological contexts across Europe, jeopardizing the long-term establishment of both newly reintroduced bear populations, as well as spatially limiting those naturally present in the environment. In response to disturbance, bears have had to reduce their ecological niche in human-dominated landscapes. Allowing humans and bears to coexist in the same landscape is a challenging task, but it is essential for the long-term survival of this newly reintroduced population that are otherwise at risk of extinction.
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Hillesheim, Benjamin James. "Cranial Morphological Distinctiveness Between Ursus arctos and U. americanus." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etd/3261.
Повний текст джерелаАнотація:
Despite being separated by millions of years of evolution, black bears (Ursus americanus) and brown bears (Ursus arctos) can be difficult to distinguish based on skeletal and dental material alone. Complicating matters, some Late Pleistocene U. americanus are significantly larger in size than their modern relatives, obscuring the identification of the two bears. In the past, fossil bears have been identified based on differences in dental morphology or size. This study used geometric morphometrics to look at overall differences in cranial shape and used step-wise discriminant analysis to identify specific characters that distinguish cranial morphology between black and brown bears. Such differences could prove important in identifying fossil bears when crania are present but teeth are missing. Furthermore, being able to properly identify U. arctos and U. americanus crania is important in understanding evolutionary and ecological distinctions among both fossil and modern bears. Principal components, discriminant, and thin plate spline analyses indicated a clear morphological separation between the crania of U. americanus and U. arctos and highlighted key identifying features including a more convex forehead and a narrower, more elongate rostrum in U. arctos than U. americanus.
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Virmaja, Tommy. "Skillnader i födoval mellan brunbjörnshonor (Ursus arctos) med och utan årsungar." Thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-63608.
Повний текст джерелаАнотація:
Inom födosöksteori söker och konsumerar djur föda på ett sätt som maximerar deras förmåga att reproducera sig och få sina gener representerade i kommande generationer. För att åstadkomma detta måste individer ibland anpassa sina beteenden. Brunbjörnhonor (Ursus arctos) med årsungar måste bland annat dela den föda de hittar med ungarna. För att inte riskera att ungarna dödas av hannar så har honor med årsungar under parningsperioden mindre hemområden och rör sig mindre under ett dygn än vuxna honor utan årsungar. Med bakgrund av dessa olikheter undersöks ifall honor med årsungar konsumerar annan föda jämfört med honor i andra reproduktiva kategorier. En spillningsinsamling från GPS-märkta björnar gjordes i västra Hälsingland och norra Dalarna under 2015 från 25:e maj till 11:e oktober. Inför dataanalysen delades säsongen upp i två perioder vid den 15:e juli på grund av olikheter i födotillgång samt att parningssäsongen slutar. En frekvensanalys gjordes av individernas spillningar som resulterade i en icke signifikant skillnad mellan honor med och honor utan årsungars födoval. En undersökande dataanalys av volymprocent antyder dock att det kan finnas skillnader i mängd av vissa födoämnen under parningsperioden. Dessa skillnader fanns i kategorierna ben, älghår samt övriga växtmaterial. Även om studien lider av liten provstorlek med endast fyra honor med årsungar i var och en av de båda perioderna tycks undersökningen originell med en upplösning på individnivå. Tidigare skandinaviska födovalsanalyser hos brunbjörnen har gjorts med spillning som minsta enhet.According to foraging theory, animals seek and consume food in ways that maximize their ability to reproduce and have their genes represented in future generations. In order to achieve this, individuals must sometimes adapt their behaviors. Females of the brown bear (Ursus arctos) with cubs of the year must share the food they find with their cubs. To protect the cubs from being killed by males in the mating period, females with young have smaller home ranges than other adult females and move less on a daily basis than other females. In view of these differences my hypothesis is that females with yearlings consume different food items than other females. A fecal collection from GPS-marked brown bears was made in 2015 in the northern Dalarna county and northwestern county of Gävleborg in Sweden from 25 May to 11 October. Prior to the data analysis, the season was divided into two periods, 25 May to 15 July and 16 July to 11 October, based on differences in food availability and season (mating vs non-mating season). A frequency analysis detected no significant differences in food items consumed for either period. However, an exploratory data analysis of percent volume of different food items suggests that there may be differences in the amount of certain foods during the mating period. These differences were found for the food categories, bone, moose hair and other plant material. Although the study suffers from a small sample size with only four females with cubs of the year in each of the two periods, this study is relatively novel with a resolution at the individual level. Previous food item analyzes of the brown bear in Scandinavia have been done with fecal samples as the smallest unit.
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Kopatz, A. (Alexander). "Genetic structure of the brown bears (Ursus arctos) in Northern Europe." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526204307.
Повний текст джерелаАнотація:
Abstract Wild populations of large carnivores in Europe were almost wiped out during the last centuries. Nowadays, the number of brown bears in North and Eastern Europe has increased, and the current situation suggests that these populations have recovered or are in the process of recovery. Knowledge of the population genetic consequences of demographic recovery in large carnivores, especially across national borders and on broader geographical scales, is still limited. In this study, we collected 3,757 fecal and hair samples as well as 881 tissue samples from brown bears across Northern Europe, with a focus on the Finnish population and neighboring areas, to investigate the population structure, connectivity, and genetic diversity on a spatial as well as a temporal scale. Bayesian clustering analysis of the population structure suggested the division of brown bears in Northern Europe into several genetic clusters, and the subdivision of the Finnish population into a northern and southern subpopulation. The estimation of gene flow pointed to better connectivity of the bears between Southern Finland and Western Russia, while migration between Scandinavia and Northern Finland as well as between Scandinavia and Southern Finland/Western Russia appeared to be restricted. Genetic clusters identified in Finland, Russia and Northern Norway displayed high genetic diversity, which was among the highest reported in wild brown bears. Recovery of the Finnish population has been accompanied by a detected range expansion towards the north, while genetic differentiation between clusters has decreased and genetic diversity has increased in the southern population, suggesting expansion from the south. Our results demonstrated that the immigration of bears from Russia still plays a major role in the Finnish bear population; however, connectivity between the Finnish-Russian population and Scandinavian bears appears to be restricted and should be improved, as well as regularly monitoredTiivistelmä Suurpetojen luonnonpopulaatiot hävisivät Euroopasta melkein kokonaan viimeisten vuosisatojen aikana. Ruskeakarhujen määrä on viime aikoina kasvanut Pohjois- ja Itä-Euroopassa, ja karhupopulaatiot ovat toipuneet tai toipumassa. Tieto demografisen toipumisen geneettisistä seurauksista populaatioissa on varsin rajoittunutta etenkin laajemmassa maantieteellisessä mittakaavassa, yli valtiorajojen. Keräsimme tätä tutkimusta varten 3757 uloste- ja karvanäytettä ja 881 kudosnäytettä Suomesta ja sen lähialueilta. Tarkoituksenamme oli kartoittaa Pohjois-Euroopan karhupopulaatioiden geneettistä rakennetta ja monimuotoisuutta, sekä populaatioiden välisiä yhteyksiä huomioiden ajallinen ja maantieteellinen ulottuvuus. Bayesiläisen ryhmittelyanalyysin perusteella Pohjois-Euroopan karhut jakaantuvat useaan geneettiseen ryhmään. Suomen populaatiossa erottuivat eteläinen ja pohjoinen alapopulaatio. Analyysit geenivirran määrästä osoittivat, että Etelä-Suomen ja Länsi-Venäjän karhupopulaatiot ovat yhteneväisemmät, kun taas migraatio Skandinavian ja Pohjois-Suomen sekä Etelä-Suomen ja Länsi-Venäjän välillä vaikuttaisi olevan rajoittunutta. Suomesta, Venäjältä ja Pohjois-Norjasta tunnistetut alaryhmät olivat geneettisesti hyvin monimuotoisia, ja muuntelu oli korkeampaa kuin koskaan aiemmin karhuilla havaittu. Suomen karhupopulaation toipuessa ja levitessä pohjoiseen, geneettinen erilaistuminen maan sisällä on vähentynyt ja eteläisen alapopulaation monimuotoisuus kasvanut. Tämä viittaa populaation laajentumiseen etelästä käsin. Tulosten perusteella karhujen tulomuutto Venäjältä on yhä tärkeää Suomen populaatiolle. Suomen ja Venäjän karhupopulaatioiden yhteyttä Skandinavian karhupopulaatioihin tulisi seurata ja parantaa
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McCann, Robert Keith. "Activity measures of free-ranging grizzly bears (Ursus arctos) in the Flathead drainage." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30082.
Повний текст джерелаАнотація:
Between 1984 and 1988, 4756 hours of activity data were collected on 15 different grizzly bears (Ursus arctos) in the Flathead drainage of southeastern British Columbia and adjacent portions of Montana. Data were collected with the aid of portable chart recorders that recorded the output from motion-sensitive radio collars. While many benefits stem from remote sensing of a study animal as intractable as the grizzly, both the method of data collection and the assumptions employed in translating chart recordings into quantitative measures of bear activity may affect conclusions drawn.
Major objectives of this study were: 1) to assess the validity of procedures employed to translate continuous chart recordings of signal patterns from motion-sensitive radio collars into quantitative measures of bear activity; 2) to assess whether active and inactive bout lengths were related to sex and age related differences in energetic requirements and seasonal differences in food type; and 3) to document activity budgets and patterns as functions of sex, age, season, and the daily solar cycle.
In the absence of concurrent visual observations of grizzly bears and recorded signal patterns, the validity of procedures used to interpret chart recordings was assessed by estimating percent of time active (%TA) under varying definitions of active and inactive bouts, and by comparing %TA to values found by other researchers. Estimates of %TA were stable over the range of activity bout definitions examined. Stability resulted from bears spending most of their time in active and inactive bouts > 30 min duration. Estimates of %TA for this study agreed with results on other populations. Over the non-denning portion of the year, grizzly bears were active about 55% of the time.
Analyses of bout durations were plagued by a bias against active bouts to be monitored in their entirety, because when active, bears frequently moved out of range of the chart recorder. The distribution of activity over the 24-hour cycle differed from many other studies in that bears in the Flathead were active mostly in daylight hours. A greater use of darkness by bears in the fall, compared to other seasons, may be related to available daylight or to avoidance of hunters. While activity patterns were generally bimodal with activity peaks in morning and evening, the morning activity peak was not strongly tied to sunrise. Activity in the morning generally reached a peak 1 or more hours after sunrise. Seasonal trends in activity budgets conformed to physiological changes in bears necessitated by requirements for denning. Significant individual variation exists in both activity patterns and budgets, and may be related to body size, to frequency dependent foraging strategies, or to differing competitive ability for defendable resources among sex-age classes of bears.Land and Food Systems, Faculty of
Graduate
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Bellemain, Eva. "Genetics of the scandinavian brown bear (Ursus arctos) : implications for biology and conservation." Université Joseph Fourier (Grenoble), 2004. http://www.theses.fr/2004GRE10168.
Повний текст джерелаАнотація:
Cette thèse traite de 1'application de l'outil moléculaire, en combinaison avec les données de terrain, pour la gestion, la conservation et la compréhension de la biologie et du comportement de l'ours brun (Urslls areros) Scandinave. La première partie de cette thèse est une partie méthodologique, dans laquelle nous avons développé des aspects techniques en biologie moléculaire (notamment par la définition de protocoles d'amplification d'ADN à partir d'échantillons fécaux) et en analyse de parenté. La seconde partie concerne l'application de ces outils dans l'étude et la gestion des populations. Nous avons évalué plusieurs estimateurs de tai11e de population à partir soit d'un échantillonnage non invasif et de méthodes moléculaires, soit de méthodes de terrain traditionnelles, et déterminé que l'estimateur le plus fiable était celui du programme MARK, basé sur un principe de capturemarquagc-recapture à partir de données génétiques. La population d'ours brun en Suède a étéestimée à 2200 individus en 2004. Le système d'appariement de l'ours brun a été étudié en relation avec l'infanticide sexue11ement sélectionné (SSI), à partir des al:alyses de parentés. Le SSI serait une stratégie reproductive des mâles. Les femelles emploieraient des contrestratégies au SSI en s'accouplant avec plusieurs mâles afin cie confondre les paternités et avec les mâles 1es plus susceptibles de commettre l'infanticide. Les mâles les plus hétéroz. Ygotes et les plus gros seraient préférentiellement sélectionnés par les femelles, probab1ement p<1r un mécanismc post copulatifThis thesis deals with the application ofmo1ecular tools, combined with field data, in wildlife management, in conservation and in understanding biology and behavior of the Scandinavian brown bear (UrslIs arc/os). The first part of this thesis is a methodological part, in which we deve10ped or reviewed technical aspects in molecular biology (particularly, we defined protocols to ampli fy DNA from fecalsamples) and in parentage analysis; the second part is devoted to the application of molecular genetics for managing Populátions. We evaluated several population size estimators, either from non invasive sampling é1lldmolecular methods, or from traditional field methods, and determined that the most reliable estimator was the one from programm MARK, based on a capture-mark-recapture principle, from genetic data. The brown bear populationin sweden was estimated to be around 2200 individuals in 2004. The brown bear mating system was studied in relation with sexually selected infanticide (SSI), from parentage analyses studies. SSlmight be an adaptive male mating strategy. Fema1es might employ counter strategies such as multiple male-mating to confuse paternities and mating with future potentia11y infanticidalmales. Most heterozygous and leu'ger males would be preferentially selected by females, probably through a post copulatory mechanism
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Pigeon, Karine. "Plasticité comportementale de l’ours grizzli (Ursus arctos horribilis) dans un contexte de changements climatiques." Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26065.
Повний текст джерелаАнотація:
L’étude de la plasticité comportementale s’attarde aux réponses physiologiques et comportementales des individus face aux contraintes de leur environnement. Les changements climatiques modifient les conditions du milieu et ont le potentiel d’influencer les composantes biodémographiques des individus. L’étude des liens mécanistiques entre le comportement animal et les conditions du milieu est donc utile à la compréhension des impacts potentiels des changements climatiques sur les individus. Le premier volet de ma thèse s’attarde aux liens entre les conditions du milieu, le comportement d’hibernation et la sélection de tanière de l’ours grizzli, une espèce menacée en Alberta. Ce volet révèle que l’abondance de nourriture à l’automne ainsi que le statut reproducteur des individus sont liés aux variations observées dans les dates d’entrée en tanière tandis que les conditions météorologiques à large échelle et le statut reproducteur des individus expliquent bien les dates de sorties de tanières. Ce volet démontre aussi que les caractéristiques physiques des tanières ne diffèrent pas entre les sexes et que pour creuser leurs tanières, les mâles et les femelles sélectionnent des attributs du paysage similaire. À large échelle, l’ours grizzli évite les zones humides et choisi des peuplements de conifères en haute altitude associés à une grande disponibilité de nourriture de haute qualité au printemps. À l’échelle du domaine vital et à l’échelle locale, l’ours grizzli choisi des peuplements de conifères associés à un fort couvert latéral et vertical, à une faible disponibilité de nourriture de haute qualité à l’automne, à une forte abondance d’Hedysarum spp. ainsi qu’à une faible densité de routes. Le second volet s’attarde à la sélection de l’habitat et à la thermorégulation durant la période active et mets en évidence les contraintes thermiques associées à une augmentation de la température ambiante sur les patrons de sélection de l’habitat. La sélection de l’habitat de l’ours grizzli selon les saisons et durant la journée dépendait de la température ambiante et ce, davantage pour les mâles que pour les femelles. Plus la température ambiante était élevée, plus la sélection de peuplements ouverts qui abondent en nourriture de haute qualité augmentait durant les périodes les plus fraîches de la journée et plus la sélection de ces mêmes peuplements diminuait durant les périodes les plus chaudes de la journée. Ma thèse approfondie les connaissances concernant les facteurs intrinsèques et extrinsèques influençant le comportement d’hibernation et met en évidence l’influence de la thermorégulation sur la sélection de l’habitat chez l’ours. Mes résultats contribuent à une meilleure compréhension des facteurs déterminant la distribution des individus et améliore notre capacité à prédire l’effet des changements climatiques globaux sur les grands mammifères.The study of behavioural plasticity aims at understanding the physiological and behavioural responses of individuals to limiting factors. Climate change has the potential to influence the life history of individuals by altering environmental conditions. Thus, studying the mechanistic links between animal behaviour and environmental conditions is necessary to understand the potential impacts of climate change on individuals. The first part of my thesis focuses on the links between environmental conditions, hibernation behaviour, and habitat selection of grizzly bears, a threatened species in Alberta, Canada. The phenology of den entry and exit was driven by sex and reproductive status, food availability in autumn, winter precipitation, and spring temperature. There was no difference in the dimensions and characteristics of dens excavated by male and female grizzly bears, and males and females selected similar landscape attributes to dig their dens. At the broadest scale investigated, grizzly bears avoided wetlands and selected high-elevation dry conifer stands with abundant high-quality spring foods. At the home-range scale and within the den vicinity, grizzly bears selected dense conifer stands associated with little high-quality autumn food and abundant Hedysarum spp. in areas with low road densities. The second part of my thesis focuses on the links between habitat selection and thermoregulation during the active season, and highlights the thermal constraints associated with increasing ambient temperatures on habitat selection patterns. Grizzly bear habitat selection followed a daily and seasonal pattern that was influenced by ambient temperature, with adult males showing a stronger response than females to warm temperatures. With increasing ambient temperatures, male and female grizzly bears increased their selection for open stands with abundant food resources during the coolest periods of the day, and concurrently decreased their selection for these open stands during the warmest periods of the day. My thesis increases our understanding of the role of intrinsic and extrinsic factors on hibernation behaviour, habitat selection, and thermoregulation constraints of grizzly bears. Ultimately, my results enhance our understanding of the factors regulating the distribution of individuals in time and space; improving our ability to predict the potential impacts of climate change on large mammals.
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Bogner, Emily, Blaine W. Schubert, and Josh X. Samuels. "Differentiating Black Bears (Ursus americanus) and Brown Bears (Ursus arctos) Geographically using Linear Measurements of Teeth and Identification of Ursids from Oregon Caves National Monument." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/asrf/2019/schedule/39.
Повний текст джерелаАнотація:
North American black bears (U. americanus) and brown bears (U. arctos) can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. Ursid teeth have a high degree of variability and morphological features are not always diagnostic. This study utilized a large database of lower tooth lengths (p4, m1, m2, and m3) and ratios (p4/m1, m2/m1, m3/m1, p4/m3, m2/m3) in an attempt to differentiate U. americanus and U. arctos in North America. Further, this project examined how these linear measurements differ in response to ecoregion, latitude, and climate. Analysis of variance (ANOVA) found significant differences between U. americanus and U. arctos from across North America for every variable studied. Stepwise discriminant analyses (DA) found lengths separated species better than ratios with 99.1% correct classification versus 77.5% correct classification for ratios. When sexes were analyzed, ANOVA only found significant differences for lengths while DA found lengths and ratios could not accurately distinguish between sexes; only 72.1% of sexes were classified correctly while utilizing lengths and 61% for ratios. Seventeen previously identified fossil specimens from across North America, in addition to the ORCA specimen, demonstrated the utility of this study, confirming several identifications and rejecting others, proposing the need for new designations.
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Gonzalez, Ofelia. "Causes et conséquences de la variation en taille de portée chez l'ours brun (Ursus Arctos)." Mémoire, Université de Sherbrooke, 2011. http://savoirs.usherbrooke.ca/handle/11143/4918.
Повний текст джерелаАнотація:
La taille de portée est une composante importante de l'aptitude phénotypique d'un individu. La variabilité du nombre de jeunes produits parmi différentes espèces a souvent été explorée, mais peu d'études ont été en mesure d'approfondir le principe de compromis entre le nombre et la taille des jeunes de façon spécifique aux grands mammifères. Le suivi long terme des populations de mammifères de grande taille offre la possibilité de dissocier des petits mammifères les composantes de la variabilité en taille de portée ainsi que le compromis entre nombre et taille des jeunes. En ce sens, une réduction de la taille de portée par mortalité juvénile en nature permet la manipulation des portées chez les espèces expérimentalement difficile à étudier. L'objectif général de mon étude était d'analyser les causes et les conséquences de variation en taille de portée chez l'ours brun (Ursus arctos) en Scandinavie à l'aide d'une base de données de 24 années. Le premier objectif était d'identifier les facteurs occasionnant la variabilité en taille de portée. Le deuxième objectif était de quantifier l'impact des caractéristiques maternelles et du sexe ratio sur la masse des oursons d'un an, en prenant en compte les effets de la taille de portée. Finalement, j'ai exploré les conséquences de la réduction de la taille de portée par mortalité en termes de masse corporelle chez les oursons d'un an. Mes analyses ont révélées [i.e. révélé] que l'âge de la mère est en majeure partie responsable de la variation de la taille de portée. Les femelles les plus jeunes produisaient le moins d'oursons par portée et par conséquent engendraient les masses totales de portée les plus faibles. Par contre, la taille corporelle des mères expliquait davantage la variabilité de la masse des oursons d'un an, alors que le sexe ratio n'expliquait ni la taille de portée, ni la masse des oursons. Il semble donc que les déterminants de la taille de portée les plus souvent observés chez les petits mammifères n'aient pas tous la même importance chez les grands carnivores. En effet, ni la taille corporelle de la mère, ni les conditions environnementales traduites par l'indice NDVI n'ont pu expliquer la taille de portée chez l'ours brun. Seul l'effet de l'âge de la mère était cohérent avec les études de petits mammifères. Finalement, j'ai décelé un compromis entre le nombre et la masse des oursons d'un an, ainsi qu'une compétition au sein des portées. Effectivement, la masse des oursons d'un an était négativement reliée à la taille de portée et en plus, une réduction de la taille de portée favorisait le gain en masse des oursons survivants. Ce gain en masse observé chez l'ours brun, soit environ 7 à 8%, est d'un ordre semblable à celui retrouvé parmi plusieurs études de petits mammifères. Ces résultats sont d'un intérêt considérable en ce qui concerne l'étude de la variabilité en taille de portée qui s'avère fondamentale pour la compréhension des stratégies de reproduction chez différentes espèces. Ils pourront être potentiellement applicables aux espèces de grands mammifères pour lesquelles le suivi des reproductions est difficilement réalisable, ou encore aux espèces chez qui les infanticides jouent un rôle prédominant dans la mortalité des jeunes. En effet, l'utilisation de réductions naturelles de la taille de portée peut devenir un moyen intéressant d'évaluer différents coûts à la reproduction, spécialement chez les grands mammifères pour qui le nombre relativement faible de jeunes produits rend la compétition au sein des portées difficile à estimer.
Книги з теми "Ursus arcto"
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Nyholm, Erik S. Ruskeakarhu (Ursus arctos arctos L.). Porvoo: Söderström, 1990.
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U.S. Fish and Wildlife Service., ed. Grizzly bear: Ursus arctos horribilis. [Washingon, D.C.?]: The Service, 1995.
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U.S. Fish and Wildlife Service., ed. Grizzly bear: Ursus arctos horribilis. [Washingon, D.C.?]: The Service, 1995.
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U.S. Fish and Wildlife Service, ed. Grizzly bear: Ursus arctos horribilis. [Washingon, D.C.?]: The Service, 1995.
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Batmȯnkhiĭn, Mizhiddorzh. Goviĭn baavgaĭ - Mazaalaĭ: Ursus arctos gobiensis. Ulaanbaatar: Admon Print, 2013.
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Mattson, David J. Causes and consequences of dietary differences among Yellowstone grizzly bears (Ursus arctos). S.l: s.n., 2000.
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Swenson, Jon E. Action plan for the conservation of the brown bear in Europe (Ursus arctos). Strasbourg: Council of Europe, 2000.
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Desrochers, Mélanie. Relationship between environmental characteristics and the distribution of grizzly bears, Ursus arctos, Kluane National Park, Yukon. [Sherbrooke, Québec]: Université de Sherbrooke, Dép. de géographie et télédétection, 2002.
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Gibson, Lea. Estimating the potential for grizzly bear (Ursus arctos horriblis) recovery in the North Cascades ecosystem of Washington State. Bellingham, WA: Huxley College of Environmental Science, Western Washington University, 2003.
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Bear attacks: Their causes and avoidance. Toronto: M&S, 2003.
Знайти повний текст джерелаЧастини книг з теми "Ursus arcto"
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Lüps, Peter. "Ursus arctos." In Säugetiere der Schweiz / Mammifères de la Suisse / Mammiferi della Svizzera, 357–60. Basel: Birkhäuser Basel, 1995. http://dx.doi.org/10.1007/978-3-0348-7753-4_69.
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Eisenberg, Cristina. "Grizzly Bear (Ursus arctos)." In The Carnivore Way, 83–111. Washington, DC: Island Press/Center for Resource Economics, 2014. http://dx.doi.org/10.5822/978-1-61091-208-2_5.
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Swenson, Jon E., Hüseyin Ambarlı, Jon M. Arnemo, Leonid Baskin, Paolo Ciucci, Pjotr I. Danilov, Miguel Delibes, et al. "Brown Bear (Ursus arctos; Eurasia)." In Bears of the World, 139–61. Cambridge University Press, 2020. http://dx.doi.org/10.1017/9781108692571.013.
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Haroldson, Mark A., Melanie Clapham, Cecily C. Costello, Kerry A. Gunther, Katherine C. Kendall, Sterling D. Miller, Karine E. Pigeon, et al. "Brown Bear (Ursus arctos; North America)." In Bears of the World, 162–95. Cambridge University Press, 2020. http://dx.doi.org/10.1017/9781108692571.014.
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Mather, David. "“Dear, Honored Guest”." In Bears, 48–70. University Press of Florida, 2020. http://dx.doi.org/10.5744/florida/9781683401384.003.0003.
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Bears are represented in Minnesota’s archaeological record through rock art, effigy earthworks, and portable art, but most frequently through zooarchaeology. Most identified bone fragments are American black bears (Ursus americanus), with rare identifications of grizzly bears (U. arctos). These finds are found throughout the state, but are most frequent in the forested biomes of the Laurentian Mixed Forest and Eastern Broadleaf Forest. The sites are archaeological expressions of bear ceremonialism, culturally connected to the Dakota, Ojibwe, or related American Indian nations, and descriptions by native elders and cultural anthropologists Irving Hallowell and Ruth Landes. Analyses of body part representation and taphonomy (such as burned or calcined bone) allows interpretation of sites representing feasts or bear graves where the remains were respectfully placed. Traditions of bear ceremonialism in Minnesota also include cultural manifestations of bear power, such as by healers, warriors, spiritual societies, or clans.
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Kuntze, A., P. Hunsdorff, and O. Kuntze. "Weitere hfimatologische und biochemische Befunde von gesunden und kranken Droiden (Thalarctos maritimus, Ursus arctos und Helarctus malayanus)." In 11. Mai bis 15. Mai 1988 in Sofia, 399–406. De Gruyter, 1988. http://dx.doi.org/10.1515/9783112649008-066.
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Ervynck, Anton, and An Lentacker. "An investigation into the transition from forest dwelling pigs to farm animals in medieval Flanders, Belgium." In Pigs and Humans. Oxford University Press, 2007. http://dx.doi.org/10.1093/oso/9780199207046.003.0018.
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There is ample evidence to show that in medieval Europe, unlike today, pigs (Sus scrofa f. domestica) were herded in woodland (see for example ten Cate 1972; Laurans 1975; Mane 1997). For England, this statement has been contested (Rackham 1976, 1980, 1986), but a recent re-evaluation of the historical data indicates that pig husbandry traditions there were the same as in continental Europe (Wilson 2003). Nowadays, pigs have almost everywhere become farm animals, at best living outdoors in semi-confinement near farmhouses, or, at worst, being reared in intensive indoor units with very limited freedom of movement. At some point in time the animals thus made the transition from forest dwellers to farmyard inhabitants, a process that is hardly documented by historical data, or at least little investigated by historians. The aim of this chapter is to investigate whether the analysis of animal remains from archaeological sites can recognize this transition by identifying changes in the characteristics of diachronic pig populations, indicative of differing animal husbandry regimes. Flanders (in present-day Belgium) was one of the most densely populated regions in medieval Europe, and as such, represents an appropriate case study area where the transition from forest to farmyard pigs can be explored. Historical data from Flanders confirm that deforestation was already very advanced towards the end of the High Medieval period (10th–12th centuries AD), so much so that reforestation campaigns were implemented (be it not always successfully) during Late Medieval times (13th–15th centuries AD) (Verhulst 1990; Tack et al. 1993; Tack & Hermy 1998). Deforestation, together with overhunting, resulted in the local extinction of wild woodland mammal species such as brown bear (Ursus arctos) in the 12th century, and wild boar (Sus scrofa) and red deer (Cervus elaphus) towards the end of the Middle Ages (Ervynck et al. 1999). In fact, in Flanders, virtually no parcel of land has been continuously under forest since medieval times, a phenomenon illustrated, for example, by the poverty of the carabid beetle fauna (an insect group with poor (re-)colonizing capacities) in present-day woodlands (Desender et al. 1999).
Тези доповідей конференцій з теми "Ursus arcto"
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Kokolova, L. M. "Brown bear Dirofilaria ursi (ursus arctos arctos) in Yakutia." In Scientific dialogue: Medical issues. TsNK MOAN, 2019. http://dx.doi.org/10.18411/sciencepublic-15-07-2019-06.
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McGee-Lawrence, Meghan E., Samantha J. Wojda, Lindsay N. Barlow, Alesha B. Castillo, Oran Kennedy, Janene Auger, Hal L. Black, O. Lynne Nelson, Charles T. Robbins, and Seth W. Donahue. "Grizzly Bears (Ursus Arctos Horribilis) and Black Bears (Ursus Americanus) Prevent Trabecular Bone Loss During Disuse (Hibernation)." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-204998.
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Reduced skeletal loading causes cortical and trabecular bone loss in humans and other animals, but trabecular bone responds to disuse more rapidly and shows greater losses than cortical bone for a given period of inactivity [1–2]. Manifestations of disuse on trabecular bone include unbalanced bone remodeling, decreased bone mineral density, and compromised bone architecture [3].
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Estraviz-López, García-Vázquez, and Grandal-D´Anglade. "Quantitative classification of metapodial bones of Ursus spelaeus and Ursus arctos from Northwestern Iberia using multivariate analysis." In XVIII Encuentro de Jóvenes Investigadores en Paleontologia. Nova.id.fct, 2021. http://dx.doi.org/10.21695/cterraproc.v1i0.418.
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Bogner, Emily L., Blaine Schubert, and Joshua X. Samuels. "DENTAL MEASUREMENTS IN BLACK BEARS (URSUS AMERICANUS) AND BROWN BEARS (URSUS ARCTOS): DISTINGUISHING THE SPECIES THROUGH TIME AND SPACE." In 67th Annual Southeastern GSA Section Meeting - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018se-313078.
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GUSKOV, V. YU. "GENETIC DIVERSITY OF MARGINAL POPULATIONS OF TWO BEARS SPECIES: BROWN BEAR URSUS ARCTOS LINNAEUS, 1758 AND ASIAN BLACK BEAR URSUS THIBETANUS G. CUVIER, 1823." In 5TH MOSCOW INTERNATIONAL CONFERENCE "MOLECULAR PHYLOGENETICSAND BIODIVERSITY BIOBANKING". TORUS PRESS, 2018. http://dx.doi.org/10.30826/molphy2018-20.
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Parres, Aida, Santiago Palazón, Laura Xicola, Pierre-Yves Quenette, Jerome Sentilles, Jean-Jacques Camarra, Ivan Afonso, et al. "Activity Patterns of the Reintroduced Brown Bears (Ursus arctos) in the Pyrenees Estimated by Photo-trapping Camera." In 5th European Congress of Conservation Biology. Jyväskylä: Jyvaskyla University Open Science Centre, 2018. http://dx.doi.org/10.17011/conference/eccb2018/108128.
Повний текст джерелаЗвіти організацій з теми "Ursus arcto"
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Farley, Sean D., Herman Griese, Rick Sinnott, Jessica Coltrane, Chris Garner, and Dave Battle. Brown Bear (Ursus arctos) Habitat Use and Food Resources on Elmendorf Air Force Base, Alaska. Fort Belvoir, VA: Defense Technical Information Center, October 2007. http://dx.doi.org/10.21236/ada480156.
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Huijser, MP, J. W. Duffield, C. Neher, A. P. Clevenger, and T. Mcguire. Final Report 2022: Update and expansion of the WVC mitigation measures and their cost-benefit model. Nevada Department of Transportation, October 2022. http://dx.doi.org/10.15788/ndot2022.10.
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This report contains an update and an expansion of a cost-benefit model for wildlife-vehicle collisions and associated mitigation measures along highways, that was originally calculated in 2007 US$ and published in 2009. The direct cost values (vehicle repair, human injuries, human fatalities) were updated for deer, elk, and moose, and expanded by including additional species: gray wolf (Canis lupus), grizzly bear (Ursus arctos), and free ranging or feral domesticated species including cattle, horse, and burro. The costs associated with collisions were also expanded by including passive use, or nonuse values associated with the conservation value of selected wild animal species. The total costs (in 2020 US$) associated with a collision with deer, elk and moose were about 2-3 times (direct costs only) or about 3-4 times higher (direct costs and passive use values combined) compared to the values in 2007 US$. The passive use costs associated with threatened species (wolf, grizzly bear) were higher or much higher than the direct costs. The costs associated with mitigation measures (especially fences and wildlife crossing structures) were also updated and supplemented with new data. New cost-benefit analyses generated updated or entirely new threshold values for deer, elk, moose, and grizzly bear. If collisions with these large wild mammal species reach or surpass the threshold values, it is economically defensible to install the associated type and combination of mitigation measures, both based on direct use and passive use parameters and their associated values. The trend in increasing costs associated with vehicle repair costs, costs associated with human injuries and fatalities, and through including passive use values for wildlife is that we learn that the implementation of effective mitigation measures can be considered earlier and more readily than based on the cost-benefit model published in 2009.