No description available.

Climate change can affect habitat availability and species interactions at several spatial and temporal scales. I explored niche partitioning and spatial variation of Rock (Lagopus muta) and White-tailed Ptarmigan (L. leucura) in southwest Yukon. I examined habitat selection of foraging areas within a population and patches within foraging areas in a sympatric population of Rock and White-tailed Ptarmigan. At the larger foraging area scale, Rock Ptarmigan used areas with greater shrub cover compared to White-tailed Ptarmigan. At the smaller patch scale, both species selected patches with greater rock cover, but differed in other patch features. Second, I examined spatial variation in abundance of both ptarmigan species between the Ruby and Kluane Ranges using pellet count and transect surveys. Relative abundance was lower in the Kluane Range based on pellet counts, but transect surveys proved inadequate as a measure of population density. The Kluane Range also had fewer positive degree days above 0 C and a greater mean standard deviation of NDVI, and was composed of finer textured colluvium compared to the Ruby Range, which could influence relative abundance of ptarmigan. / Ecology

Willow grouse ( Lagopus lagopus) and rock ptarmigan (Lagopus muta) are popular game birds in Sweden. I have analysed hunting statistics from Jämtland county in Sweden and investigated if there is a significant correlation between willow grouse density and Catch-Per-Unit-Effort (CPUE) by nationalities and type of permits. The included nationalities were Swedish, Nordic and non-Nordic hunters. Type of permits that were analysed were day-, municipality and county permits. There was no correlation between the grouse density and CPUE variables. However, significant correlations were found when correlating yearly number of harvested grouse  with the CPUE variables. For willow grouse, significant correlations were found between Swedish, Non-Nordic, day and municipality permit hunters and for rock ptarmigan, Swedish, Nordic, day and municipality permit hunters. I also found that international hunters was more effective than Swedish hunters, as well as hunters with day permit, which was true for both species. There were also differences between the CPUE variables between two time periods, 2004-2012 and 2013-2021. In the second period, the CPUE of Swedish hunters, day and municipality permit hunters have decreased for willow grouse. The CPUE also decreased for non-Nordic during the second period for rock ptarmigans. Significant difference in hunting pressure were also found between the two time periods, where the later period had slightly higher hunting pressure than the first period. The results of this study strengthened previous studies where no correlation has been found between the grouse density and CPUE.

No description available.

This thesis investigates how changes in population size and spatial movements of individuals have shaped the distribution and abundance of neutral genetic variation in the arctic fox. This is done through mitochondrial and microsatellite DNA analyses on samples covering most of the species’ distribution, but with special emphasis on Scandinavia. On the species level, nucleotide diversity was relatively low, which indicated a historical expansion in population size in connection with the onset of the last Ice Age. It is thus possible that the glacial cycles have affected the arctic fox, and other cold-adapted species, in a way opposite to their effect on temperate species. Gene flow seemed to be high among arctic fox populations on a circumpolar scale, especially between populations where lemmings are the main food source, which could be explained by the spatial synchrony in lemming fluctuations. In Scandinavia, the arctic fox went through a severe demographic bottleneck in the beginning of the 20th century. Although some genetic variation was lost during this bottleneck, the loss was much smaller than expected, probably due to post-bottleneck gene flow from Russia. The arctic fox in Scandinavia is divided into four relatively isolated populations. Within each population, dispersal seemed to be high despite the high availability of empty territories close to natal dens, which supported the hypothesis that lemming fluctuations influence arctic fox dispersal. Genetic analyses on samples collected between 1989 and 2004 indicated an ongoing genetic drift and inbreeding within the Scandinavian populations. Furthermore, individual genetic variation was negatively associated with fitness, which could be attributed to an ongoing inbreeding depression. Analyses on faecal samples suggested that arctic foxes move higher up in the mountains and farther from the tree-line during summer compared to winter. This seasonal shift in distribution is probably caused by interspecific competition from the red fox, which is likely to be higher during summer due to red fox predation on arctic fox cubs. The results presented in this thesis have several implications for the conservation of the Scandinavian arctic fox. The finding of four isolated populations within Scandinavia and an ongoing inbreeding depression suggests that the risk of extinction is higher than previously thought. Conservation actions need to be taken in all populations to be effective, and could include genetic restoration through translocation.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Made available in DSpace on 2015-04-11T13:56:16Z (GMT). No. of bitstreams: 1 Dissertacao-Simone Monfort Abitbol.pdf: 4995564 bytes, checksum: bebf179306348c72672879f3b03c883b (MD5) Previous issue date: 2008-06-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Ochroma lagopus Swartz (Malvaceae) is commonly known as pau-debalsa and occurs naturally from southern Mexico to Bolivia. In Brazil is common in the state of Amazonas. It is a tree species and its main importance is related to the use of their wood in the manufacturing of boats and rafts and with potential for use for reforestation in the region. The objective is describe and illustrate morfoanatomics aspects of seed of pau-de-balsa. The work began with the collection of fruit and trees in the Estação Experimental de Silvicultura Tropical, do Instituto Nacional de Pesquisas da Amazônia INPA, Manaus/AM. The study was conducted morphology of the Laboratório de Botânica Agroflorestal (LABAF) da Universidade Federal do Amazonas and anatomical analysis in laboratory anatomy, no Núcleo de Microscopia e Microanálise (NMM) and the Laboratory of Micorrhyzum / BIOAGRO da Universidade Federal de Viçosa (MG). Been made measurements of length, width, thickness and moisture content. The parameters were observed morphological external and internal seed for morphological description, the use of techniques for light microscopy, and scanning electron microscopy to characterize anatomical, and employee test histochemical with Sudan Red B, Nile Blue, Lugol, Floroglucine, Xilidine Pounceau, Astra Blue and Basic Fuchsin, Rutênio Red and Ferric chloride. Ochroma lagopus contains 8,8% of moisture content. The seed is estenospérmic, albuminose, axial invaginated plicate embryo, foliaceous cotyledons. The tegument is formed by cells expanded arranged in palisading. The endosperm and the embryo cells have thin walls with varying shape and size. In the histochemical analysis of the tegument the tests gave positive responses to polysaccharides, lignin and phenolic compounds and endosperm and the embryo to proteins, lipids and starch. / Ochroma lagopus Swartz (Malvaceae) é vulgarmente conhecida por pau-debalsa e ocorre naturalmente desde o sul do México até a Bolívia. No Brasil é comum no Estado do Amazonas. É uma espécie arbórea onde sua principal importância está relacionada à utilização de sua madeira, na manufatura de barcos e jangadas e com potencialidade de uso para reflorestamento na região. Objetivou-se descrever e ilustrar os aspectos morfoanatômicos das sementes de pau-de-balsa. O trabalho foi iniciado com a coleta dos frutos e árvores matrizes na Estação Experimental de Silvicultura Tropical, do Instituto Nacional de Pesquisas da Amazônia INPA, Manaus/AM. O estudo da morfologia foi realizado no Laboratório de Botânica Agroflorestal (LABAF) da Universidade Federal do Amazonas e a análise anatômica no Laboratório de Anatomia, no Núcleo de Microscopia e Microanálise (NMM) e no Laboratório de Micorrizas/BIOAGRO da Universidade Federal de Viçosa (MG). Foram feitas medições de comprimento, largura, espessura e teor de umidade. Foram observados os parâmetros morfológicos externos e internos das sementes para descrição morfológica, o uso de técnicas de microscopia de luz e microscopia eletrônica de varredura para caracterização anatômica, sendo empregado teste histoquímico com Sudan Red B, Azul do Nilo, Lugol, Floroglucina, Xilidine Pounceau, Azul de Astra e Fucsina Básica, Vermelho de Rutênio e Cloreto Férrico. Ochroma lagopus contém 8,8% de teor de umidade. A semente é estenospérmica, albuminosa, embrião axial invaginado plicado, cotilédones foliáceos. O tegumento é formado por células alargadas dispostas em paliçada. O endosperma e o embrião possuem células de paredes delgadas com formato e tamanho variável. Na análise do tegumento com os testes histoquímicos deram respostas positivas para polissacarídeos, lignina e compostos fenólicos. No endosperma e embrião para proteínas, lipídios e amido.

<p>Genetic variation within and among populations is a result of past and ongoing processes. Among the most important of such processes are dispersal, habitat fragmentation and selection. This thesis use neutral genetic variation as a tool to investigate these processes in three bird species.</p><p>In the Siberian jay, the timing of dispersal is dependent on social dominance among siblings. Mark-recapture data, radio-tracking and genetic variation was used to investigate whether timing of dispersal had an effect on dispersal distance. The results show that early dispersing individuals also disperse longer. In the same species, genetic correlation between neighbours was used to find areas with high production of philopatric individuals, which could be indicative of high habitat quality.</p><p>Great snipe populations in northern Europe have a breeding range divided into two regions. A Q_ST-F_STapproach was applied to study variation in selection between regions. Differentiation between the regions in neutral molecular markers was low, indicating high gene flow, or short time available for neutral divergence. Morphological divergence between the regions was high, and Q_ST > F_ST, which indicates divergent selection. Thus, neutral genetic markers can be misleading in identifying evolutionary significant units, and the Q_ST-F_ST approach might be valuable to identify targets for conservation.</p><p>Rock ptarmigan, or its ancestors, originated in Beringia, and spread throughout the Holarctic region. Their distribution has subsequently been affected by glaciations, most likely leading to withdrawals and re-colonisations. Neutral genetic variation among five populations around the northern Atlantic was investigated. There was strong genetic structure among the populations, and evidence that Scandinavian rock ptarmigan has been isolated from other populations for considerable time. Rock ptarmigan in Svalbard showed slightly lower genetic variation than others, and comparisons with other studies suggested an eastern colonisation route to Svalbard.</p>

Genetic variation within and among populations is a result of past and ongoing processes. Among the most important of such processes are dispersal, habitat fragmentation and selection. This thesis use neutral genetic variation as a tool to investigate these processes in three bird species. In the Siberian jay, the timing of dispersal is dependent on social dominance among siblings. Mark-recapture data, radio-tracking and genetic variation was used to investigate whether timing of dispersal had an effect on dispersal distance. The results show that early dispersing individuals also disperse longer. In the same species, genetic correlation between neighbours was used to find areas with high production of philopatric individuals, which could be indicative of high habitat quality. Great snipe populations in northern Europe have a breeding range divided into two regions. A QST-FST approach was applied to study variation in selection between regions. Differentiation between the regions in neutral molecular markers was low, indicating high gene flow, or short time available for neutral divergence. Morphological divergence between the regions was high, and QST &gt; FST, which indicates divergent selection. Thus, neutral genetic markers can be misleading in identifying evolutionary significant units, and the QST-FST approach might be valuable to identify targets for conservation. Rock ptarmigan, or its ancestors, originated in Beringia, and spread throughout the Holarctic region. Their distribution has subsequently been affected by glaciations, most likely leading to withdrawals and re-colonisations. Neutral genetic variation among five populations around the northern Atlantic was investigated. There was strong genetic structure among the populations, and evidence that Scandinavian rock ptarmigan has been isolated from other populations for considerable time. Rock ptarmigan in Svalbard showed slightly lower genetic variation than others, and comparisons with other studies suggested an eastern colonisation route to Svalbard.