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Área de vida e uso de habitat por fêmeas de veado-campeiro (Ozotoceros bezoarticus) nos diferentes períodos reprodutivos, no Pantanal Sul-Matogrossence / Home-range and habitat use by females of Pampas Deer (Ozotoceros bezoarticus) in different reproductive periods, in Pantanal Sul-MatogrossenseNatalia Fraguas Versiani 20 May 2011 (has links)
As populações de veado-campeiro vêm sofrendo constantes ameaças, principalmente pela caça excessiva e destruição de seu habitat. A escassez de conhecimento sobre a biologia da espécie dificulta a elaboração de diferentes formas de manejo. Assim, há necessidade de estudos básicos para a instituição de programas para a conservação do veado-campeiro, principalmente no Brasil. O presente estudo teve como objetivos estimar o tamanho da área de vida de fêmeas de veado-campeiro, além de quantificar e comparar o uso de habitat pelas mesmas nos períodos reprodutivos e não-reprodutivos no Pantanal Sul-Matogrossense. Foram utilizadas quatro fêmeas de veado-campeiro em vida livre marcadas com colares de GPS modelo ATS® G2110, as quais tiveram suas localizações registradas a cada 13 horas por um período de aproximadamente 12 meses. Os cálculos para área de vida foram feitos através do programa ArcView® GIS versão 3 Extensão Animal Movement, usando os métodos do Mínimo Polígono Convexo (MPC) com 100% das localizações, e Kernel fixo com 95%, 70% e 50% de probabilidade de uso, sendo os dois últimos para estimativas dos centros de atividade. As fêmeas tiveram uma área de vida anual média de 549,88ha ± 124,76 quando estimado pelo MPC e 258,69ha ± 34,54 quando estimado por Kernel com 95% de probabilidade de uso. Quanto às áreas de uso mensais por status reprodutivo, não houve diferença significativa entre os meses (p > 0,05), evidenciando apenas uma pequena diminuição no tamanho das áreas de vida durante o período de aleitamento e um aumento nas épocas de acasalamento. Os habitats foram estabelecidos pelo tipo de vegetação predominante na área e foram caracterizados por imagem de satélite Landsat-5 e verificação in loco da região de estudo. Para verificar se houve uso desproporcional entre as categorias de habitats em relação à disponibilidade em suas respectivas áreas de vida foi usado o teste qui-quadrado de qualidade de ajustamento (chi-square goodness-of-fit test) e posterior estimativa do intervalo simultâneo de confiança de Bonferroni. Na análise anual, os habitats campo e baía foram selecionados, apesar deste último ser o menos abundante, enquanto floresta e caronal foram evitados pelas fêmeas de veado-campeiro. No entanto, ao analisarmos a seleção de habitat mensalmente para comparar o uso entre os diferentes status reprodutivos, o habitat campo tendeu a ser preferido, mas seu uso foi igual ao disponível em todos os períodos. Sendo assim, este estudo elucidou algumas informações sobre a ecologia do veado-campeiro, a fim de facilitar o desenvolvimento de programas de conservação para a espécie. / The pampas deer populations have been under constant threats, mainly by excessive hunting and habitat destruction. The lack of knowledge about the biology of the species hampers the development of different forms of management. Thus, there is a need for basic studies of establishment of conservation programs, mainly in Brazil. This study aimed to estimate the size of home-range, to quantify and compare the habitat use by females in reproductive and non-reproductive periods rights in Pantanal Sul-Matogrossense. Four females of pampas deer were marked with GPS collars, model ATS® G2110, which had recorded their locations every 13 hours for approximately 12 months. The calculations for home-range were made using the Arcview® GIS version 3 Extension Animal Movement, using the methods of the minimum convex polygon (MPC) with 100% of the locations, and fixed Kernel 95%, 70% and 50% of probability, being the last two for estimating the activity centers. The females had an annual home-range average of 549.88 ± 124.76 ha when estimated by MPC and 258.69 ± 34.54 ha when estimated by Kernel with 95% of probability. For the monthly home-ranges for reproductive status, no significant difference among months (p > 0.05), showing only a slight decrease in the size of home-range during the suckling period, increasing in the mating seasons. The habitats were established by the type of dominant vegetation and characterized by landsat-5 imaging satellite and in loco verification of the study area. To determine if there was disproportionate use of habitats between the categories regarding availability in their respective home-range, was used the chi-square goodness-of-fit test and subsequent estimation of Bonferroni simultaneous confidence intervals. In annual analysis, field and bay habitats were selected, despite the last being the less abundant, while forest and caronal were avoided by females of pampas deer. However, when analyzing the monthly habitat selection to compare the use between the different reproductive status, the habitat field tended to be preferred, but its use was equal to that available in all periods. Thus, this study clarified some informations about the ecology of pampas-deer, facilitating conservation programs development for the species.
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Wolverine habitat selection, diet and conservation geneticsKoskela, A. (Anni) 08 October 2013 (has links)
Abstract
Rare and elusive species are difficult to study, because they are usually secretive, solitary, occur at low densities and have large home ranges. Wolverines (Gulo gulo) can both hunt and scavenge for food. In Fennoscandia, wolverines co-exist with either wild or semi-domesticated reindeer, which constitute their most important winter food. Approximately half of the 180–220 Finnish wolverines are found in northern Finland within the reindeer management area. However, the other half of the population is distributed in eastern and central Finland, and the ecology of wolverines especially in this area is poorly known. This research examined the habitat selection, diet and population genetics of wolverines in northern and eastern Finland. The results suggest that wolf presence is one of the most important variables influencing the habitat selection of wolverines. This finding supports the speculative idea that wolverines might benefit from being sympatric with wolves through increased scavenging opportunities. Furthermore, both the reproductive status of wolverines and the availability of different prey items were found to affect the wolverine diet. In northern Finland, semi-domesticated reindeer and mountain hare were the most frequently utilized prey species for breeding female wolverines. In eastern Finland, the most important food source for breeding females was moose carrion, whereas males and non-breeding females heavily utilized mountain hares. These results support the predictions of the optimal foraging theory, suggesting that wolverines opportunistically utilize the food source that is most energy-efficiently available. In areas with a low density of medium-sized ungulates, scavenging of wolf- and human-killed carrion plays an essential role in food acquisition by wolverines. According to the results of a population genetics investigation, two wolverine subpopulations exist in Finland: a northern and an eastern one. The overall genetic variability was found to be low, and signs of a recent population bottleneck were detected in both populations. It is likely that the wolverine populations in Finland would benefit from improved connectivity between them, but also with neighbouring populations in Scandinavia and north-eastern Russia. / Tiivistelmä
Ahma (Gulo gulo) tunnetaan sekä haaskansyöjänä että keskikokoisia hirvieläimiä ja pienriistaa saalistavana petona. Fennoskandian alueella peuran kesy tai villi muoto on ahman merkittävin saalislaji. Noin puolet Suomen 180–220 ahmasta elää Pohjois-Suomessa poronhoitoalueella, ja loput Itä- ja Keski-Suomessa. Poronhoitoalueen ulkopuolella elävien ahmojen ekologiaa on tutkittu erityisen vähän. Väitöstyössäni tarkastelin ahman habitaatinvalintaa, ruokavaliota ja populaatiogenetiikkaa pääasiassa Pohjois- ja Itä-Suomen alueilla. Tutkimukseni tulokset osoittivat, että suden läheisyys oli yksi tärkeimmistä ahman habitaatinvalintaan vaikuttavista tekijöistä. Tämä havainto tukee hypoteesia, jonka mukaan ahma saattaisi hyötyä susien läheisyydestä suuremman haaskatiheyden ansiosta. Todennäköisesti ahmat elävät mielellään samoilla seuduilla susien kanssa, mutta kaihtavat läheistä kanssakäymistä välttääkseen killansisäisen saalistuksen. Tutkimusteni perusteella sekä ahman lisääntymistila että alueen saaliseläinten saatavuus vaikuttivat ahman ruokavalioon. Poro ja metsäjänis olivat lisääntyvien ahmanaaraiden tärkein ravintokohde Pohjois-Suomessa. Itä-Suomessa merkittävin lisääntyvien naaraiden ravintokohde oli hirvi, jota ahmat hyödyntävät lähinnä haaskojen muodossa, mutta urokset ja ei-lisääntyvät naaraat sen sijaan saalistivat eniten metsäjänistä. Ahmat siis näyttävät hyödyntävän opportunistisesti sitä ravintokohdetta, joka kullakin alueella on energiatehokkainta saavuttaa. Susien ja ihmisten jälkeensä jättämät haaskat ovat merkittävä ravintolähde ahmoille alueilla, joilla keskikokoisten hirvieläinten tiheydet ovat alhaisia. Ahman populaatiogeneettinen tutkimus osoitti, että Suomen ahmat ovat geneettisesti jakautuneet kahteen alapopulaatioon, pohjoiseen ja itäiseen. Ahmakannan geneettinen monimuotoisuus oli pientä, ja molemmissa alapopulaatiossa oli nähtävissä merkkejä äskettäisestä pullonkaulailmiöstä. Populaatioiden välisen geenivirran määrän tulisi olla nykyistä korkeampi, jotta ahmakannan elinvoimaisuuden voisi katsoa olevan turvattu tulevaisuudessa.
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Identifier les contraintes pour la conservation des dernières girafes de l’Afrique de l’Ouest : déterminants de la dynamique de la population et patron d’occupation spatiale / Identifying conservation constraints for the last West African giraffe : population dynamics determining factors and spatial distribution patternSuraud, Jean-Patrick 16 December 2011 (has links)
Le défi de la protection des espèces menacées en Afrique est de concilier de façon durable les objectifs de conservation de la nature, et la nécessité de développement économique des populations humaines. Au Niger, survivent aujourd'hui les dernières girafes d'Afrique de l'Ouest (Giraffa camelopardalis peralta). Ces girafes sont unique à plusieurs titres : (i) elles constituent les seules représentantes de la sous espèce peralta (ii), elles vivent dans une région fortement anthropisée (iii) elles vivent dans une zone non protégée, (iv) et elles ne cohabitent avec aucun prédateur. En 1996, la population était au bord de l'extinction avec seulement 50 individus. Malgré des signes de restauration observés ces dernières années, la sous-espèce est inscrite depuis 2008 dans la liste rouge des espèces menacées de l'UICN (Union Internationale pour la Conservation de la Nature) avec le statut « en danger ». Quels sont les facteurs qui pourraient limiter le taux de croissance maximum récemment observé dans cette population? Est-ce que les conjonctures favorables à l'augmentation de la population sont durables? Aborder les questions de conservation des populations met en avant le besoin de connaitre les paramètres démographiques de la population concernée, et les paramètres environnementaux qui conditionnent sa distribution spatiale. Nous avons réalisé une analyse de l'historique des comptages, puis, nous avons déterminé les paramètres démographiques de la population grâce à une approche par Capture Marquage Recapture. Une analyse spatiale à plusieurs échelles nous a permis de caractériser la distribution des girafes aux niveaux de la population et du troupeau (à partir d'observations directes), et de mesurer la sélection de l'habitat au niveau individuel (à partir d'un suivi par colliers GPS) / One of the main challenges for endangered species protection in Africa is to find a sustainable way of integrating objectives of nature conservation with the economic development needs of the local human population. Last West African giraffe population, Giraffa camelopardalis peralta, lives in Niger. These giraffe are unique for several reasons: (i) they represent the only population of peralta sub-species, and (ii) they live in an area densely populated by humans, (iii) which is unprotected and (iv) without predators. In 1996, this giraffe population was almost extinct, with only 50 individuals remaining. Despite signs of population recovery, the sub-species has been classified as “endangered” according to the IUCN Red List assessment criteria. What are the limiting factors for the maximum annual growth rate that has been recorded over the last years in the population? Are favorable conjunctures to this population increasing sustainable? Assessing population conservation requires knowledge of demographic parameters and understanding of the environmental factors driving its spatial distribution. Census data from 1996 to 2009 were analyzed and then demographic parameters through a capture-markrecapture method were determined. A multi-scale spatial analysis allowed me to determine giraffe distribution at both population and herd level (through observations), and to measure habitat selection at the individual level (through GPS satellite collars). Census results, almost exhaustive from 2005 to 2008 highlited an annual growth rate of 12%. This is the maximum growth rate for a giraffe population, and fits with the theoretical maximum growth rate for the species. At the population and herd level, giraffe distribution patterns are driven by food availability. These food resources are seasonally distributed and impacted by human activities. Habitat selection shows that during dry season, giraffe avoid village proximity, where disturbance is high. However, at night giraffe move closer to villages where food resource quantity and quality are higher (tree density, granaries). The use of bean field crop suggests that some cultivated crops gain in attraction and even become favourable to giraffe. This might explain the increase of human-giraffe conflicts. My results clearly show the importance of taking human activities and perception into account, when assessing wildlife conservation strategies
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Demography, Movement Patterns, and Habitat Selection of Blanding's Turtles at Canadian Nuclear Laboratories in Chalk River, OntarioHawkins, Emily January 2016 (has links)
The development and implementation of effective species and population-specific management strategies requires population-specific information. To demonstrate the relative extirpation risk associated with various road mortality scenarios for a population of Blanding’s turtles at Canadian Nuclear Laboratories in Chalk River, Ontario, a Population Viability Analysis was conducted. Road mortality of two adult females every ten years resulted in population extirpation within 200 years relative to a stable population not experiencing road mortality. To accommodate informed decision-making for the management of this species at risk, the movement patterns and habitat selection of this Blanding’s turtle population were described. There was no significant difference between males and females in distance moved between relocations in either the spring or the summer, but turtles moved greater distances in the spring than in the summer. Annual and seasonal home range size did not differ between the sexes or between spring and summer periods. A compositional analysis indicated Blanding’s turtles preferred marsh habitats over bog, swamp, lake, and upland. Matched-paired logistic regression was used to determine selection of microhabitat features, such as type of vegetation, in the spring and summer. Turtles preferred sites with warmer air temperatures, shallower water, a higher availability of open water, and greater coverage of emergent and floating vegetation types in the spring period. In the summer period, turtles preferred sites characterized by cooler, deeper water, a higher availability of open water, and greater coverage of emergent and floating vegetation types. This population of Blanding’s turtles appears to be relatively small and the continued threat of road mortality indicates a delicate situation for its persistence. Considering seasonally preferred habitats will best inform management decisions for seasonal work restrictions and future development plans.
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Seasonal movements of black-tailed deer on northern Vancouver IslandHarestad, Alton Sidney January 1979 (has links)
Columbian black-tailed deer (Qdocoileus hemionug cplumbianus Richardson) were radio-tagged in a deep snowfall region on northern Vancouver Island, British Columbia. These deer were monitored to determine seasonal movements and habitat use. Deer exhibited either resident or migratory movement patterns. Resident deer made seasonal shifts in their home range centres but their seasonal home ranges overlapped. In migratory deer, summer home ranges were separated from both spring and winter home ranges, although their spring and winter home ranges overlapped. Altitudinal migrations occurred by deer moving between high and low elevation habitats. Horizontal migrations occurred by deer moving between a small tributary valley and the main valley.
Seasonal movements of black-tailed deer result from habitat selection by deer seasonally moving to more favourable habitats as determined by more available energy and nutrients, and lower risk of predation. The causal differences between vertical and horizontal migrations as well as seasonal shifts in home range centres can be resolved by a model of habitat selection based on these factors.
The densities of available digestible dry matter in Amabilis Fir - Twisted Stalk, and Mountain Hemlock - Copperbush associations are comparable with those in the shrub and conifer serai stages. This abundance of deer food in high elevation habitats suggests that forest harvesting in high elevations will not affect deer populations, if their other habitat requirements are met. In areas where forested summer ranges already exist,
low elevation logging of Sword Fern - Western Red Cedar, Deer Fern - Western Hemlock, and Western Hemlock - Plagiothecium associations will provide deer with sources of abundant food closer to their winter ranges than the high elevation summer ranges. Use of these food sources may result in only a redistribution and not an increase in the deer population. Logging of Amabilis Fir - Western Hemlock, Salal - Douglas-fir, and Salal - Western Hemlock associations may be detrimental to deer populations because of their need for these habitats during winter.
Management policies emphasizing preservation of severe winter range could be detrimental to deer populations. Habitat management for black-tailed deer must include provision of mild winter range as well as severe winter range. Because mild winter range provides deer with greater amounts of available energy and nutrients, it may be as important to the over-winter survival of deer as is severe winter range.
The mobility of black-tailed deer and their sensitivity to snow suggest that few deer would be trapped in high elevations by early snowfalls. Corridors joining high and low elevations appear unnecessary to facilitate deer migrations. / Forestry, Faculty of / Graduate
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Microhabitat Use by Blanding’s Turtles (<i>Emydoidea blandingii</i>) and Wood Turtles (<i>Glyptemys insculpta</i>) in a Shared LandscapeReine K Sovey (8812556) 08 May 2020 (has links)
<p>Understanding and adequately
protecting habitat is at the forefront of modern conservation concerns. Turtles
are especially vulnerable to habitat loss, and are therefore a top priority for
habitat research. To help meet this need, I used radio telemetry to collect
microhabitat data from two imperiled species of turtles that occupy a military
base in Michigan. Preliminary data exploration was carried out with principal
components analysis (PCA). Microhabitat use was then modeled for each species using
conditional logistic regression (CLR), with a generalized estimating equation
(GEE) element to limit bias due to individual variation. Finally, I compared
habitat use between sympatric Blanding’s and Wood Turtles using Mann-Whitney U
tests and Mood’s median tests to investigate the degree of overlap in
microhabitat use when these species occur in sympatry. Evidence for
microhabitat selection in Blanding’s Turtles was weak, suggesting that they
likely do not make habitat decisions at this level. Wood Turtles selected sites
that were farther from water and had fewer trees, less overstory canopy cover,
and more ground cover. Additionally, the two species differed in several
aspects of microhabitat use; Wood Turtles were more terrestrial and more
tolerant of tree cover than Blanding’s Turtles. Patterns of microhabitat use
found in this study match previously observed behavior of turtles in high
quality habitat, suggesting that managers should work to maintain the habitat
currently available at Camp Grayling. Additionally, because both turtle species
were associated with open canopy, selective logging could benefit turtles
provided care is given to timing and methods. </p>
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The Effects of Habitat Management on Wildlife Use in a Managed Loblolly Pine ForestMcCollum, Johannah Reed 10 August 2018 (has links)
To improve habitat quality for wildlife, habitat managers prescribe various disturbances. Habitat management techniques alter the vegetation structure, composition, and quality, changing food and cover resources and availability. To investigate how habitat management and vegetation heterogeneity affect space use by wildlife species, I deployed 81 camera-traps and collected fine scale vegetation data across a variety of treatments (i.e., canopy reduction, prescribed fire, and herbicide application) in a managed loblolly pine forest. I created a new method for accounting for imperfect detection and error in camera count data. My method provided better inference about the effects of variables on animal use. Species responded differently to different functional groups of plants, but predicted use from generalized additive models showed higher use in the most intensively managed pine stands, indicating that management promotes animal use by improving habitat quality. Animals used every treatment, indicating the need for heterogeneity in resources when managing wildlife.
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Multi-Scale Habitat Selection of Antillean Manatees (Trichechus manatus manatus) in Sian Ka'an Biosphere Reserve, Southeastern MexicoGagnon, Émilie 06 September 2023 (has links)
The distribution of organisms across the globe forms non-random patterns that are based on their selection for certain environmental features. Habitat selection is the study of how organisms choose where they live. It is a fundamental behavior shaping several ecological and evolutionary processes. The hierarchical nature of the environment makes it imperative to consider multiple scales in habitat selection studies. Even though there is extensive coverage of scaling in habitat selection literature, most published papers only consider one scale. To our knowledge, habitat selection studies of the Antillean manatee (Trichechus manatus manatus) have never included more than one spatial scale. Hence, we modeled Antillean manatee habitat selection in the Sian Ka'an Biosphere Reserve, in Mexico, at two spatial scales: study area and 1 km buffer. We used GPS coordinates of opportunistic encounters (n = 102) recorded since 2009. We randomly generated 500 pseudo-absences per presence point for both scales, and extracted the environmental conditions from each point: seagrass abundance (leaf area index or LAI), water depth, and shortest distance to land, closest river and closest resting hole. We fitted a binomial regression of the probability of presence as a function of the environmental parameters using a Bayesian approach. Our results show that the probability of manatee presence increases in proximity to resting holes for both scales and increases with land proximity at the large-scale. Overall, we showed that proximity to resting holes is the most important feature of habitat selection for Antillean manatees in Sian Ka'an, followed by proximity to land. This study demonstrates the importance of multi-scale designs in habitat selection and highlights the need for more studies looking at the use and ecological implications of manatee resting holes.
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Nest site selection and productivity of the Spanish imperial eagle Aquila adalberti population of Doñana National Park, SpainBisson, Isabelle January 1996 (has links)
No description available.
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The Dynamics of Sarcoptic Mange in an Urban Coyote (<i>Canis latrans</i>) PopulationWilson, Evan C. 19 July 2012 (has links)
No description available.
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