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  • 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

Life and death of the mountain hare in the boreal forest of Sweden /

Dahl, Fredrik. Willebrand, Tomas. January 2005 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2005. / Appendix includes reproductions of five papers and manuscripts, two co-authored with Tomas Willebrand. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix of papers.
2

Population fluctuations in mountain hares : a role for parasites? /

Newey, Scott. January 2005 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2005. / Appendix includes reproductions of six papers and manuscripts co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix of papers.
3

Factors controlling the density of wild populations, with special reference to fluctuations in the vole (Microtus) and the snowshoe rabbit (Lepus americanus)

Chitty, Dennis January 1949 (has links)
No description available.
4

A COMPARATIVE STUDY OF THERMOREGULATION AND WATER BALANCE IN HARES AND RABBITS OF THE SONORAN DESERT

Hinds, David Stewart, 1939- January 1970 (has links)
No description available.
5

Molekularni diverzitet i genetički signali lokalnih adaptacija vrste Lepus europaeus Pallas, 1778 u heterogenim uslovima sredine / Molecular diversity and genetic signatures of local adaptations in brown hares (Lepus europaeus Pallas, 1778) from heterogenous landscapes

Stefanović Milomir 23 July 2020 (has links)
<p>U&nbsp; ovom&nbsp; radu&nbsp; sagledan&nbsp; je&nbsp; molekularni&nbsp; diverzitet,&nbsp; filogeografska&nbsp; struktura,<br />prostorna&nbsp; distribucija&nbsp; molekularnog&nbsp; diverziteta,&nbsp; kao&nbsp; i&nbsp; prisustvo&nbsp; selekcionih<br />signala i genetičkih signala lokalnih adaptacija kod 251 jedinke&nbsp; vrste&nbsp; Lepus<br />europaeus (Pallas,&nbsp; 1778)&nbsp; sa&nbsp; teritorije&nbsp; Evrope&nbsp; i&nbsp; Bliskog&nbsp; Istoka,&nbsp; a&nbsp; na&nbsp; osnovu<br />analize&nbsp; varijabilnosti&nbsp; sekvenci&nbsp; D&nbsp; petlje&nbsp; mtDNK, MT-ND2,&nbsp; MT-ND6,&nbsp; MHCDQA, MHC-DQB i TLR2 gena. Uočen je visok nivo parametara molekularnog<br />diverziteta&nbsp; za&nbsp; sve&nbsp; ispitivane&nbsp; molekularne&nbsp; markere.&nbsp; Utvrđeno&nbsp; je&nbsp; postojanje<br />filogeografske&nbsp; strukturiranosti&nbsp; vrste&nbsp; na&nbsp; osnovu&nbsp; mtDNK,&nbsp; kao&nbsp; i&nbsp; asimetričan<br />protok gena jedinki sa teritorije Anadolije na teritoriju Balkana&nbsp; na osnovu D<br />petlje mtDNK, MT-ND2 i MT-ND6 gena, dok je na osnovu sekvenci D petlje<br />mtDNK uočena gotovo tri puta veća stopa protoka gena sa Balkana u centralnu<br />i&nbsp; zapadnu&nbsp; Evropu.&nbsp; Utvrđeno&nbsp; je&nbsp; prisustvo&nbsp; signala&nbsp; poizivne&nbsp; selekcije&nbsp; u&nbsp; okviru<br />MT-ND6&nbsp; gena,&nbsp; kao&nbsp; i&nbsp; efekat&nbsp; klimatskih&nbsp; parametara&nbsp; (precipitacije)&nbsp; na<br />distribuciju&nbsp; proteinskih&nbsp; varijanti&nbsp; ND6C&nbsp; i&nbsp; ND6F,&nbsp; kao&nbsp; moguća&nbsp; posledica<br />regionalnih adaptacija na razlike u sredinskim uslovima. Pokazano je odsustvo<br />signala&nbsp; filogeografske&nbsp; strukturiranosti&nbsp; na&nbsp; osnovu MHC-DQA, MHC-DQB i<br />TLR2 gena.&nbsp; Uočeno&nbsp; je&nbsp; postojanje&nbsp; prostorne&nbsp; strukturiranosti&nbsp; na&nbsp; osnovu&nbsp; gena<br />imunskog&nbsp; sistema,&nbsp; i&nbsp; definisane&nbsp; su&nbsp; dve&nbsp; prostorne&nbsp; grupe,&nbsp; jedna&nbsp; koja&nbsp; je<br />obuhvatala&nbsp; jedinke&nbsp; sa&nbsp; teritorije&nbsp; Bliskog&nbsp; Istoka,&nbsp; i&nbsp; druga&nbsp; koja&nbsp; je&nbsp; obuhvatala<br />jedinke&nbsp; sa&nbsp; teritorije&nbsp; Evropi.&nbsp; Vi&scaron;e&nbsp; vrednosti&nbsp; parametara&nbsp; molekularnog<br />diverziteta uočene su u anadolijskoj grupi, u poređenju sa evropskom grupom.<br />Uočen je signal delovanja pozitivne i negativne selekcije u MHC-DQA i MHCDQB genima, kao i signal negativne selekcije u TLR2 genu. Pokazan je efekat<br />klimatskih&nbsp; parametara&nbsp; na&nbsp; distribuciju&nbsp; najzastupljenijih&nbsp; proteinskih&nbsp; varijanti<br />MHC-DQA&nbsp; i&nbsp; MHC-DQB&nbsp; gena kao&nbsp; indirektni&nbsp; pokazatelj&nbsp; imunogenetičkih<br />adaptacija&nbsp; na&nbsp; sredinski&nbsp; uslovljene&nbsp; pretpostavljene&nbsp; razlike&nbsp; u&nbsp; distribuciji<br />patogena.&nbsp; Mehanizam&nbsp; oblikovanja&nbsp; varijabilnosti&nbsp; MHC&nbsp; gena&nbsp; rezultat&nbsp; je<br />uzajamnog delovanja mutacija, rekombinacija i selekcije.</p> / <p>In&nbsp; this&nbsp; doctoral&nbsp; dissertation,&nbsp; molecular&nbsp; diversity,&nbsp; phylogeographic&nbsp; structure,<br />spatial&nbsp; distribution&nbsp; of&nbsp; molecular&nbsp; diversity,&nbsp; detection&nbsp; of&nbsp; possible&nbsp; selection<br />signals&nbsp; shaping&nbsp; the&nbsp; evolution of&nbsp; these&nbsp; genes,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; presence&nbsp; of<br />local/regional&nbsp; adaptations&nbsp; in&nbsp; correlation&nbsp; was&nbsp; examined&nbsp; in&nbsp; 251&nbsp; brown&nbsp; hares<br />from&nbsp; Europe&nbsp; and&nbsp; the&nbsp; Middle East&nbsp; based&nbsp; on&nbsp; the&nbsp; analyses&nbsp; of&nbsp; mitochondrial&nbsp; D<br />loop,&nbsp; mitochondrially&nbsp; Encoded&nbsp; NADH&nbsp; Dehydrogenase&nbsp; 2&nbsp; (MT-ND2),<br />mitochondrially&nbsp; Encoded&nbsp; NADH&nbsp; Dehydrogenase&nbsp; 6&nbsp; (MT-ND6),&nbsp; exon&nbsp; 2&nbsp; of<br />MHC Class II genes MHC-DQA,MHC-DQB and Toll Like Receptor 2 (TLR2)<br />gene sequences. A high level of molecular diversity was found based on the all<br />applied&nbsp; markers.&nbsp; Strong&nbsp; signal&nbsp; of&nbsp; phylogeographical&nbsp; and&nbsp; spatial&nbsp; structuring<br />was&nbsp; observed&nbsp; for&nbsp; mtDNA,&nbsp; most&nbsp; likely&nbsp; as&nbsp; a&nbsp; consequence&nbsp; of&nbsp; climatic<br />perturbations&nbsp; during&nbsp; the&nbsp; Pleistocene.&nbsp; The&nbsp; evolutionary&nbsp; development&nbsp; of&nbsp; hares<br />from&nbsp; Anatolia/Israel&nbsp; to&nbsp; the&nbsp; Balkans,&nbsp; and&nbsp; furthermore&nbsp; to&nbsp; central&nbsp; and&nbsp; western<br />Europe was suggested by several lines of evidences, which include dating the<br />population&nbsp; demography&nbsp; based&nbsp; on&nbsp; D-loop&nbsp; sequences,&nbsp; the&nbsp; observed&nbsp; migration<br />patterns,&nbsp; results&nbsp; of&nbsp; demographic&nbsp; tests,&nbsp; and&nbsp; apparent&nbsp; reduction&nbsp; in&nbsp; molecular<br />diversity&nbsp; indices&nbsp; along&nbsp; this&nbsp; trajectory.&nbsp; Positive&nbsp; selection&nbsp; acting&nbsp; on MT-ND6<br />gene&nbsp; was&nbsp; detected,&nbsp; together&nbsp; with&nbsp; significant&nbsp; climatic&nbsp; effect&nbsp; shaping&nbsp; the<br />distribution&nbsp; of&nbsp; the&nbsp; most&nbsp; prevalent&nbsp; protein&nbsp; variants&nbsp; found&nbsp; in&nbsp; this&nbsp; gene,<br />supposedly&nbsp; as&nbsp; a&nbsp; consequence&nbsp; to&nbsp; local/regional&nbsp; adaptations&nbsp; due&nbsp; to&nbsp; the<br />environmentally induced different energetic requirements and optimization of<br />OXPHOS&nbsp; genes.&nbsp; On&nbsp; the&nbsp; other&nbsp; side,&nbsp; less&nbsp; evident&nbsp; phylogeographic&nbsp; signal&nbsp; and<br />absence&nbsp; of&nbsp; strong&nbsp; structuring&nbsp; was&nbsp; revealed&nbsp; in&nbsp; MHC&nbsp; genes.&nbsp; High&nbsp; diversity&nbsp; at<br />MHC genes seems to be shaped by the interplay of recombination, selection<br />mechanisms&nbsp; and&nbsp; adaptations.&nbsp; Balancing&nbsp; selection&nbsp; seems&nbsp; to&nbsp; maintain&nbsp; a&nbsp; high<br />molecular&nbsp; diversity&nbsp; within&nbsp; these&nbsp; genes,&nbsp; while&nbsp; directional selection&nbsp; promotes<br />local/regional adaptations to pathogenic landscapes, as indirectly suggested by<br />a&nbsp; significant&nbsp; effect&nbsp; of&nbsp; climatic&nbsp; parameters&nbsp; on&nbsp; the&nbsp; distribution&nbsp; of&nbsp; protein<br />variants in both examined MHC genes.</p>
6

Etude de la protostrongylose dans la population de lièvres européens (Lepus europaeus) dans le sud est de la France : approche épidémiologique et écologique / Pulmonary protostrongyliasis in populations of hares (Lepus europaeus) in the South-east of France : epidemiological and ecological approach

Lesage, Célia 04 December 2014 (has links)
Depuis 2006, une recrudescence de cas de protostrongylose, parasitose liée à la présence de nématodes au niveau pulmonaire, apparaît dans le Sud-est de la France au sein de la population de lièvres européens (Lepus europaeus). Le cycle de développement de ces parasites nécessite le passage obligatoire par un hôte intermédiaire connu pour être un mollusque gastéropode terrestre. Notre programme a pour objectif l'étude épidémiologique de la maladie et notamment l'identification des acteurs du cycle parasitaire.Basée sur une analyse morphologique et moléculaire, nous identifions : Protostrongylus pulmonalis (Frölich, 1802) fréquemment inventorié en Europe et P. oryctolagi Babos, 1955, décrit à une seule occasion en Hongrie en 1955, comme les agents responsables de la protostrongylose en France. Cette étude a permis de déposer de nouvelles séquences d'ADN de référence, utiles pour l'identification ultérieure de nos espèces parasites, en particulier les stades larvaires et sur lesquelles nous nous sommes basées pour la reconnaissance des hôtes intermédiaires intervenant dans le cycle naturel. Sur 3622 mollusques analysés, nous avons mis en évidence des larves de stade 3 (P. pulmonalis et P. oryctolagi) à partir de 18 individus, appartenant à la famille des Hygromiidae et dont l'identification spécifique repose sur différents marqueurs moléculaires (de loin préférables aux critères morphologiques). Au sein des populations de lièvres, nous identifions l'âge et l'environnement, en lien avec la répartition des hôtes intermédiaires comme les facteurs de risque de la maladie. Le parasitisme, concernant près de 55% des animaux, n'a pas eu d'effet mesurable sur l'état général de l'hôte, mais pourrait être impliquée dans une diminution de la fécondité des hases, suggérant un impact potentiel sur les dynamiques de populations de lièvres. / Since 2006, in the South-East of France, we observe an increase in the number of hares (Lepus europaeus) suffering from pulmonary protostrongyliasis, which is a parasitic disease caused by nematodes in the lungs. The development cycle of these parasites requires the obligatory pathway through an intermediate host, terrestrial gastropod mollusk. Our goal was the epidemiological study of the disease, particularly the identification of the parasite cycle.Based on morphological and molecular analysis, we identified two causative agents of pulmonary protostrongyliasis in France: Protostrongylus pulmonalis (Frölich, 1802) frequently inventoried in Europe and P. oryctolagi Babos, 1955 described only once in Hungary in 1955. Thus new reference sequences of DNA are available, which is useful for the subsequent identification of our parasite species and particularly for larvae-stage, allowing the recognition of intermediate hosts involved in their natural cycle. In total 3622 terrestrial mollusks were analyzed. We identified three-stage larvae of P. pulmonalis and P. oryctolagi from 18 individuals belonging to the family of Hygromiidae and belonging to several species identified with different molecular markers. In the hare populations, we identify the age and environment (in association with the distribution of intermediate hosts) as risk factors for the disease. The parasite, with approximately 55% of infected animals, had no measurable effect on the health status of the host, but could be involved in a decrease in the fecundity, suggesting a potential impact on population dynamics of hares.
7

Impact of the Black-Tailed Jackrabbits (Lepus Californicus) On Vegetation in Curlew Valley, Northern Utah

Westoby, Mark 01 May 1973 (has links)
The interrelations of black- tailed jackrabbits and the desertshrub vegetation on which they were feeding were studied in Curlew Valley, Northern Utah. The vegetation was described as a threecornered continuum, the corners being types dominated respectively by Artemisia tridentata, Atriplex ~ onfertifolia, and Sarcobatus vermiculatus. Jackrabbit diet was studied by microscopic analysis of plant fragments in stomachs from shot animals. The method was inaccurate, apparently because the ratio of identifiable tissues to all ingested tissues was very low, and varied between plant taxa, and seasonally. This problem seems intractable for desert shrub vegetation. The diet was similar to that reported by other workers on this species, with perennial grasses and forbs most important in sprlng and summer, shrubs in autumn and win ter. Features new to this vegetat ion were large percentages of Halogeton glomeratus, particularly in autumn and winter, and intense selection for Kochia americana. Attempts to explain the foods chosen ln terms of t heir nutrient contents were partically successful. Diet selection by large generalist herbivores was conceptualized as optimization of nutrient intake, mediated by long-delay learning, and constrained by food availability only at very low levels of availaoility. Spatial variation in jackrabbit diets confirmed this "cut-offll response to ava i 1 all i 1 i ty . Percentage utilization was estimated indirectly as jackrabbit density, times yearly food consumption per jackrabbit, times yearround percentage of each taxon in the diet, div i ded by available biomass of each taxon. Less abundant plants were more intensely used, which is expected if consumption does not vary continuously with availability. Perennial grasses, Kochia americana and possibly Grayia spinosa seemed to be under damaging pressure at high jackrabbit densities. Kochia had almost disappeared from outside a sheep- and jackrabbitproof exclosure since the 1950 1 s. In other exc1osures, the presence or absence of jackrabbits seemed to make no difference to the rate of vegetation recovery over 5-7 years after exclusion of sheep. Jackrabbit use of a crested wheatgrass seeding was concentrated ln a 300 m band around its edge.
8

On the origin of the mountain hare on the island of Gotland : By means of ancient DNA analysis

Ahlgren, Hans January 2011 (has links)
The island of Gotland houses a number of terrestrial mammalian species even though it was covered with ice during the last glacial period. The purpose of this study is to genetically analyse the mountain hare (Lepus timidus) to deduce its origin and genetic structure during different time periods, and also to discuss how it reached the island. A 130 base pair sequence of mitochondrial DNA from 38 prehistoric hares was analysed and compared to modern hares from different locations in Europe. The result shows a discrepancy among the samples creating two populations with different origin.
9

Untersuchungen zur Reproduktionsleistung von Feldhäsinnen / gleichzeitig ein Beitrag zur Ursachenfindung des Populationsrückganges dieser Wildtierart

Bensinger, Sylvie 28 November 2004 (has links) (PDF)
Im Mittelpunkt dieser Untersuchung stand die Frage, inwieweit der Feldhasenrückgang (Lepus europaeus) auf eine verminderte Reproduktion zurückzuführen ist. Zur Klärung dieser Frage wurden dabei erstmals in Deutschland die jährliche Reproduktionsleistung von Häsinnen durch den Nachweis von Plazentationsstellen (BRAY, 1998), erfasst. Die Alterbestimmung erfolgte über die etablierte Methode der Augenlinsenwägung (ANDERSON u. JENSEN, 1972; SUCHENTRUNK, 1991). Die Probenentnahme erfolgte auf den jährlichen Feldhasenjagden in 15 verschiedenen Revieren in den Jahren 1997 und 1998 im Zeitraum Oktober bis Dezember. Untersucht wurden 311 Uteri, 183 von adulten und 128 von juvenilen Häsinnen. 84% der adulten Weibchen waren nachweislich reproduktiv, bei den Junghäsinnen (unter einem Jahr alte) lag der Anteil bei 0,8%. Alle Individuen der jüngsten Altersklasse der Adulten (1-1,5 Jahre) waren fortpflanzungsaktiv, während in der Klasse der 1,5-3 Jahre alte Tiere bereits nur noch 90% reproduziert hatten. Bei Häsinnen im Alter von 3-5 Jahren lag der Wert bei 86%. Bei der ältesten Klasse (> 5 Jahre) sank der Anteil deutlich auf 54% ab. Von den 30 nichtreproduktiven adulten Häsinnen wiesen 21 pathologische Uterusveränderungen auf. Auffällig war das hohe Durchschnittsalter der nichtreproduktiven, das bei über vier Jahren lag, im Vergleich zu den reproduktiven Tieren. Im Durchschnitt wurden 9,2 Plazentationsstellen pro Uterus bei den adulten Häsinnen (nichtreproduktive miteinbezogen) gezählt. Dieser Wert entspricht den aus der Literatur bekannten Angaben. Hinweise auf eine verminderte Fertilität weiblicher Tiere als Ursache für den kontinuierlichen Rückgang der Feldhasenpopulation und dessen gleichzeitige Überalterung konnten aus diesen Ergebnissen nicht abgeleitet werden. Zu vermuten sind erhöhte Sterblichkeitsraten von Junghasen als Ursache für den bedenklichen Rückgang der Feldhasenpopulation. / The present study focuses on the question, whether the decrease in numbers of European hares (Lepus europaeus) could be due to a decrease in reproduction within that species. In order to clarify this hypothesis, this study investigated the annual reproduction performance of female European hares by counting the number of placentation sites that have been detected with a method described by (BRAY, 1998). In addition, the females agea were determined using the established method of eye lens weight as an age index (ANDERSON u. JENSEN, 1972; SUCHENTRUNK, 1991). The analysis was carried out in the years 1997 an 1998. This field investigation is the very first study addressing this question in Germany. Uterine probes were sampled on the annual hares huntings from October to December. Reproduction performance was analysed in 311 uteri, with 183 from adult and 128 from juvenile animals, respectively. While 84% of the adult animals (age: more than 1 year) showed reproduction, in contrast only 0,8% of the juvenile female hares (age: less than 1 year) were reproductive. Within the group of the youngest adult female hares (age: 1 to 1,5 years) all animals showed reproduction performance, however, reproduction proved to be already reduced to 90% in the group of 1,5 – 3 years old animals. In the group of female hares in the age from 3 – 5 years 86% displayed a reproduction performance, while finally in the oldest adult female hares (age: more than 5 years) only 54% showed signs of reproduction. Interestingly, out of 30 adult female hares that showed no sign of reproduction, 21 animals in a age older than 4 years showed pathological uterine alterations. The average number of placentation sites per uteri was 9,2 (nonreproductives include). This value is consitant with reports from the literature. Therefore, it is unlikely that cause for the decrease in population within that wild life species is due to a reduce fertility of female European hares. It seems that the higher deathrate of young hares may be the cause for the decrease of hares population
10

Možnosti zjištění zatížení lesních ekosystémů těžkými kovy pomocí jejich obsahu v parazitech zaječí zvěře

Štefek, Karel January 2014 (has links)
In this thesis the concentrations of heavy metals have been statistically appraised on the basis of samples gained from small intestines of European hare - Lepus europaeus and from an endoparasite Trichuris leporis (found by a washing method). Tha appraisal has been performed by atomic absorption spectrometry -- AAS, electrothermal atomization - ETA-AAS (for Cd, Cr, Ni, Pb), and means of atomization in the flame FAAS (Cu, Mn, Zn). The pieces of offal of hare game have been obtained from a common hunting in the localities of the Czech Republic represented by the region of South Moravia, Moravian-Silesian, Olomouc, and the Highlands. The sample collecting has been conducted from 2008 to 2012. Statistically significant differences of heavy metals concentrations have been found out between the individual localities. In addition, an endoparasite as a possible bioindicator of heavy metals load on the forest environment has been evaluated differently. Furthermore, in endoparasites there have been detected an exceeding of the hygiene limits for food. Conclusion made on the basis of all statistical analysis performed in this study says that Trichuris leporis indicates heavy metals load on ecosystems by wider range of heavy metals than the small intestine and more, considerably in the higher concentrations. Thus, Trichuris leporis can be used as a sentinel organism for the indication of heavy metals in the forest environment, at least in an area of the European hare territory.

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