• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 2
  • 1
  • Tagged with
  • 7
  • 7
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ochranářská genetika rysa ostrovida v Západních Karpatech / Conservation genetics of Eurasian lynx in the Western Carpathians

Ungrová, Lenka January 2021 (has links)
Robust monitoring combined with genetic analyses are important approaches to protect and manage large carnivore populations successfully. The aim of this master thesis is to analyse Eurasian lynx (Lynx lynx) population within whole Slovakia for the first time using 15 microsatellite loci. Noninvasive genetics is an effective tool for monitoring animal species with large home ranges and low population densities. Noninvasive samples including feces, hair, urine and buccal swabs were collected together with tissue samples from dead (mostly roadkill) individuals. 187 samples were collected between 2017-2019, resulting in 59 successful genotypes. Two samples were incorrectly determined in the field and excluded from further analyses since they were wildcat samples. For population genetics analyses and demography, the dataset from the "Veľké šelmy 2" project was extended with 98 genotypes in collaboration with the Institute of Vertebrate Biology CAS. Overall, 68 lynx individuals were detected in the dataset of 155 genotypes. Relatedness analysis resulted in 67 significant relationships of the first degree and 9 significant relationships of the second degree. These results suggest a high relatedness among the whole population. According to the present thesis, Slovakian lynx population has the third lowest...
2

Populationsutveckling och bärkraft för lodjur (Lynx lynx) i Östergötland / Population trends and carrying capacity for eurasian lynx (Lynx lynx) in Östergötland

Barrefelt, Linnea January 2019 (has links)
Jordens biologiska mångfald minskar i en allt snabbare takt, men mitt i denna ekologiska katastrof börjar arter på vissa håll att återkomma. De stora rovdjuren i Europa är ett sådant exempel. Från att ha varit försvunna från stora delar av sina utbredningsområden är de flesta populationer numera stabila eller ökande. I Skandinavien har lodjurspopulationen expanderat och efter närmare 100 års reproduktiv frånvaro förekommer åter föryngringar i Sydsverige. I Östergötland finns i dagsläget ca 50–55 individer och mycket tyder på att stammen kommer att fortsätta öka. Genom att sammanställa och analysera data från inventeringsrapporter, observationsloggar och avskjutningsstatistik har jag undersökt lodjurspopulationens utveckling i Östergötland och beräknat länets bärkraft för lo. Beräkningen av bärkraften har utgått från klövviltförekomsten samt mängden lämpligt habitat. Resultaten visar att Östergötland har gott om lämpligt habitat och en hög bytesdensitet, som är jämförbar med flera lodjurstäta områden i Europa. Givet dessa förutsättningar har Östergötland en bärkraft för lo som ligger långt över dagens populationsnivå. Uppskattningsvis kan Östergötland hålla mellan 80–140 självständiga individer. Detta skulle innebära en fördubbling av dagens antal och kunna leda till såväl positiva som negativa konsekvenser för samhället. Lodjur kan innebära ett hot mot tamboskap, men de senaste årens rapportering visar att angreppen orsakade av lodjur är begränsade. Även påverkan på klövviltstammarna är i dagsläget försumbar. På sikt skulle dock en större lodjurspopulation kunna reglera klövviltet och på så vis minska mängden trafikolyckor och skador på skog. / Global biological diversity is declining at rates comparable to historic mass extinction events. Despite this, some species are returning to their former ranges, an example being the great carnivores in Europe. After being driven to the verge of extinction, most of today’s populations have recovered to a stable level. The Eurasian lynx (Lynx lynx) has re-expanded its range in Scandinavia and, after almost 100 years, is once again reproducing in southern Sweden. There are currently about 50-55 individuals in Östergötland county, and many factors implies that their number will continue to grow. By collecting and analysing data from different governmental reports and other sources I have tried to cover the development of Östergötland’s lynx population and to calculate the carrying capacity. The calculations are based on ungulate densities and amount of suitable habitat. The results of the study show that Östergötland contains a large amount of connected woodland habitat and high densities of prey, comparable to regions in Europe with high occurrence of lynx. Given these circumstances Östergötland has the capacity to support approximately 80-140 independent individuals. These numbers are twice as large as today’s population level and if reached could lead to positive as well as negative consequences for society. The lynx is a known threat to livestock but reports from recent years suggests that lynx attacks on sheep in Östergötland are limited. The effects of the current lynx population on ungulate demographics are also negligible. Although, these effects might increase with a larger lynx population, leading to lower rates of vehicle collisions and less damage in the forestry sector.
3

Projekt podpory veřejného mínění o rysovi ostrovidovi (Lynx lynx) u dětí a mládeže v regionu Prachaticko / Project support of public opinion about European lynx (Lynx lynx) in children and youth in the region Prachaticko.

ŠVERÁKOVÁ, Barbora January 2011 (has links)
Eurasian Lynx (Lynx lynx) is included in the IUCN. It was extirpated in the Czech Republic at the beginning of the 19th century and is found thanks to the reintroduction since 1980 in the Czech Republic again. It is only wild feline in the Czech Republic. Lynx population has lost its growing trend and is decreasing mainly due to poaching. The project ?Support of public opinion about European lynx (Lynx lynx) in children and youth in the region Prachaticko? was created as a precaution against poaching. The project involved over 275 children and students. They gained new information through the teaching program in school subjects Biology, Art and Gymnastics and they made your own opinion about Lynx. Lynx is only carnivorous animal, which was and still is part of the Bohemian Forest.
4

Porovnání postojů žáků ZŠ a SŠ k velkým šelmám zejména pak k vlku obecnému (Canis lupus) a psu domácímu (Canis lupus familiaris) / Comparison of Attitudes of Primary and Secondary Schools Students to Large Carnivores, Especially the Common Wolf (Canis lupus) and Domestic Dog (Canis lupus familiaris)

Mejzr, Martin January 2012 (has links)
Today, the issues related to the presence of bears and wolves in the Czech Republic are more frequently discussed due to their occasional occurrence. The significant part of the public still considers these predators dangerous and they even think that a man is supposed to be their potential prey. A lot of surveys confirming this have been already taken, but none of them was focused on the views of primary and secondary schools students. As they are a part of the school education system, their views on the large carnivores should be mainly shaped by it. A questionnaire-based survey was used to find the attitudes of students. The first part of the questionnaire focused on the students' opinions about the dangerousness of predators, its reasons and common wolf presence in the Czech Republic. The second part of the questionnaire is focused on the domestic dog, which has wolf origins. It deals mainly with the attitudes of students to selected dog breeds, dog domestication awareness and views on the so- called "fighting breeds". This work has been aimed at identification of attitudes of the primary and secondary school students from different regions of the Czech Republic to the selected predators. The survey was also taken at primary schools in the High Tatras Mountains, an area where all the large...
5

Anthropogenic impact on predator guilds and ecosystem processes : Apex predator extinctions, land use and climate change

Pasanen Mortensen, Marianne January 2014 (has links)
Humans affect ecosystems by changing species compositions, landscape and climate. This thesis aims to increase our understanding of anthropogenic effects on mesopredator abundance due to changes in apex predator status, landscape and climate. I show that in Eurasia the abundance of a mesopredator, the red fox (Vulpes vulpes), is limited top-down by the Eurasian lynx (Lynx lynx) and bottom-up by winter severity. However, where lynx has been eradicated, fox abundance is instead related to bottom-factors such as cropland (paper I, II). Fox abundance was highest when croplands constituted 25% of the landscape (paper II). I also project red fox abundance in Sweden over the past 200 years and in future scenarios in relation to lynx density, land use and climate change. The projected fox abundance was highest in 1920, when lynx was eradicated and the proportion of cropland was 22%. In 2010, when lynx had recolonised, the projected fox abundance was lower than in 1920, but higher than in 1830. Future scenarios indicated that lynx abundance must increase in respond to climate change to keep fox at the same density as today. The results suggest a mesopredator release when lynx was eradicated, boosted by land use and climate change, and that changes in bottom-up factors can modify the relative strength of top-down factors (paper IV). From 1846-1922, lynx, wolverine (Gulo gulo) and grey wolf (Canis lupus) declined in Scandinavia due to persecution; however I show that the change in wolverine abundance was positively related to the changes in lynx and wolf abundance. This indicates that wolverine is subsidized by carrions from lynx and wolf kills rather than limited top-down by them (paper III). This thesis illustrates how mesopredator abundance is determined by a combination of top-down and bottom-up processes, and how anthropogenic impacts not only can change the structures of predator guilds, but also may modify top-down processes through changes in bottom-up factors. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted. Paper 4: Manuscript.</p><p> </p>
6

Påverkan av jakt och katastrofer på lodjursstammen (Lynx lynx) i Sverige: En sårbarhetsanalys / The effets of hunting and catastrophes on the lynx (Lynx lynx) in Sweden: A population viability analysis

Dahlberg, Julia January 2024 (has links)
The eurasian lynx (Lynx lynx) has a wide distribution and occurs in the palearctic region. In Europe, the lynx has been persecuted and exterminated from several of its natural distribution areas and has also been subject to persecution in Sweden, where a high hunting pressure led to a reduced population that almost went extinct. Today, the Swedish lynx population has recovered but is kept down by licensed hunting, which is strictly controlled due to the lynx's protection status. However, Sweden's government has backed a proposal for reduced protection that could potentially lead to higher hunting quotas and thus threaten the lynx's future, because of predators’ vulnerability to high hunting pressures and smaller populations’ vulnerability to stochastic events such as catastrophes. The purpose of this study was to investigate the development of the Swedish lynx population and how high the risk of extinction is now, with increased hunting quotas and if catastrophes would occur both with current hunting quotas and increased hunting quotas. Based on the purpose, the questions that were answered were the following: 1) What does the population development and extinction risk look like for the Swedish lynx population in the next 100 years with current hunting quotas? 2) How do higher hunting quotas affect the Swedish lynx population development and extinction risk in the next 100 years? 3) How would catastrophes with current hunting quotas and increased hunting quotas affect the Swedish lynx population development and extinction risk in the next 100 years? The questions were answered through a population viability analysis performed in Vortex 10 where four scenarios were created. In scenario 1, the null scenario, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to current hunting quotas. In scenario 2, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to current hunting quotas and catastrophes. In scenario 3, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to increased hunting quotas. In scenario 4, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to increased hunting quotas and catastrophes. The scenarios with the largest and smallest average population size after 100 years were scenario 1 and scenario 4, respectively. The growth rate was highest and lowest for scenario 1 and scenario 4, respectively. Scenarios 2, 3 and 4 had a negative growth rate. The extinction risk for scenarios 1 and 2 was 0% and scenarios 3 and 4 had an extinction risk of 1%. To conclude, the results indicate that the current hunting quotas do not threaten the Swedish lynx population, but that catastrophes have a negative impact on population growth at current hunting quotas, and that the increased hunting quotas have a negative impact as they result in a reduced population and a negative growth rate both with and without catastrophes. / Det eurasiska lodjuret (Lynx lynx) har en vid utbredning och förekommer i den palearktiska regionen. Lodjuret har i Europa förföljts och utrotats från flera av dess naturliga utbredningsområden och även i Sverige har lodjuret varit utsatt för förföljelse där ett högt jakttryck ledde till en minskad population som nästan utrotades. Idag har den svenska lodjursstammen återhämtat sig men hålls nere genom licensjakt, som är strikt kontrollerad på grund av lodjurets skyddsstatus. Däremot har Sveriges regering ställt sig bakom ett förslag till minskat skydd som potentiellt kan leda till högre jaktkvoter och därmed hota lodjurets framtid eftersom rovdjur är sårbara för höga jakttryck, samt att mindre populationer är mer sårbara för slumpmässiga händelser såsom katastrofer. Syftet med arbetet var att undersöka den svenska lodjursstammens utveckling och utdöenderisk i nuläget, vid förhöjda jaktkvoter, samt om katastrofer skulle inträffa vid nuvarande jaktkvoter respektive förhöjda jaktkvoter. Utifrån syftet besvarades följande frågeställningar: 1) Hur ser populationsutvecklingen och utdöenderisken ut för den svenska lodjursstammen under kommande 100 år med nuvarande jaktkvoter? 2) Hur påverkar högre jaktkvoter den svenska lodjursstammens populationsutveckling och utdöenderisk under kommande 100 år? 3) Hur skulle katastrofer vid nuvarande jaktkvoter respektive förhöjda jaktkvoter påverka den svenska lodjursstammens populationsutveckling och utdöenderisk under kommande 100 år? Frågeställningarna besvarades genom en sårbarhetsanalys som utfördes i Vortex 10 där fyra scenarier skapades. I scenario 1, grundscenariot, undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till nuvarande jaktkvoter. I scenario 2 undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till nuvarande jaktkvoter och katastrofer. I scenario 3 undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till förhöjda jaktkvoter. I scenario 4 undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till förhöjda jaktkvoter och katastrofer. Största respektive minsta genomsnittlig populationsstorlek efter 100 år fick scenario 1 respektive scenario 4. Tillväxthastigheten var högst respektive lägst för scenario 1 respektive scenario 4. Scenario 2, 3 och 4 hade alla en negativ tillväxthastighet. Utdöenderisken för scenario 1 och 2 blev 0% och scenario 3 och 4 hade en utdöenderisk på 1%. Resultaten tyder på att de nuvarande jaktkvoterna inte hotar den svenska lodjursstammen men att katastrofer ger en negativ påverkan på populationstillväxten vid nuvarande jaktkvoter, samt att de förhöjda jaktkvoterna har en negativ påverkan då de ger en minskad population och en negativ tillväxthastighet både med och utan katastrofer.
7

Analýza životaschopnosti ohrožených druhů zvířat v České republice / Population viability analysis of endangered species in Czech Republic

Šťastná, Andrea January 2017 (has links)
Diploma thesis analyzes the viability of the selected species populations in the Czech Republic. The thesis is divided into two main parts. The first part contains a stochastic model simulating possible scenarios of the Eurasian lynx population size in the Czech Republic. For this model program Vortex was used. The second part is focused on Time series analysis of the Grey Partridge and the Common Kingfisher population, where data was obtained from the Czech Society for Ornithology. This analysis aims on identification of factors that may affect the viability of the two bird species.

Page generated in 0.0655 seconds