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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.
91

Factors Influencing Travel Order as Proxy for Leadership and Trade-offs in Activity Budgets in Lactating and Nonlactating African Savanna Elephants

Wisniewska, Malgorzata 01 December 2011 (has links)
Nutritional and energetic needs of female mammals depend upon size or reproductive investment and shape individual activity budgets and behavioral patterns. To maximize nutritional and energetic intake females may increase time allocated to foraging or access resources through risk-prone behaviors, represented as aggression or leadership. Conversely, to minimize nutritional and energetic spending females may engage in risk-averse activities such as resting or nonaggressive social interactions. Females with the highest needs should exhibit activities and behaviors that facilitate the greatest nutritional and energetic returns or highest metabolic savings. The propensity for risk-prone behaviors may be greater among older as well as lactating females. Older individuals tend to be larger and more experienced than younger conspecifics. Moreover, lactating females are under substantially greater energetic, nutritional and water stresses than nonlactating individuals. Therefore, to fulfill greater nutritional and energetic needs, older and lactating females may allocate more time to foraging or rest or be more assertive during search for and defense of resources. I assessed the relative effects of age, reproductive condition and sex of nursing offspring on activity budgets, the frequency of risk-prone and risk-averse behaviors such as leadership propensity, and chemosensory inspection of the surroundings in female African savanna elephants (Loxodonta africana africana). To quantify activities and behavioral patterns I used focal animal sampling with continuous recording. I determined leadership by the position in a mobile herd, where the first and last positions were considered as ends, and the center was considered as a middle position. I discovered that older females stood more, were more aggressive, socialized less and traveled closer to the end of a traveling group than younger females. Females that were lactating spent more time foraging, were more aggressive and engaged in nonaggressive social interactions less frequently than their nonlactating conspecifics. Finally, females nursing female calves spent more time foraging than females nursing male calves, but the latter spent more time nursing and standing. These results elucidate how individual nutritional and energetic needs influence the activity budgets as well as the propensity to exhibit risk-prone and riskaverse behaviors in female elephants and thus add to a body of work examining mammalian female activity budgets shaped by individual differences such as age and reproductive condition.
92

Aspects of the population and feeding ecology of Microtus agrestis (L.), the field vole

Richards, Christopher Gareth Joseph January 1981 (has links)
No description available.
93

The frontal system of the Antarctic Circumpolar Current : marine mammals as ocean explorers

Boehme, Lars January 2008 (has links)
In this thesis, I describe large-scale and small-scale features of the Antarctic Circumpolar Current (ACC) by merging conductivity-temperature-depth (CTD) data obtained by novel animal-borne sensors with data obtained by more conventional means. Twenty-one CTD-Satellite Relay Data Loggers (CTD-SRDLs) were attached to Southern elephant seals (Mirounga leonina) on South Georgia in 2004 and 2005. This was part of a larger international study (Southern Elephant Seals as Oceanographic Samplers; SEaOS), in which I played a major role in developing the oceanographic approach used to integrate physical data from a range of sources, and the means to link biological findings to oceanographic parameters. The development of animal-borne oceanographic sensors and their potential place within an ocean observing system is reviewed initially. Then, I describe the Series 9000 CTD-SRDL in detail, discussing its performance in the lab and during two field experiences with Southern elephant seals and Weddell seals (Leptonychotes weddellii ). Following this, a detailed study of the ACC frontal system in the South Atlantic is presented that uses merged Argo float data and CTD-SRDL data. The structure of the frontal field revealed by this unique dataset is examined, and unprecedented insight into its variability is obtained. Amongst the important findings is that, contrary to most climate models, our in situ data suggest a northward shift of the ACC east of 40W in 2004 and 2005 compared to previous work. Next, two CTD-SRDL sections are presented to identify the locations of the ACC fronts across Drake Passage, and an empirical relationship between upper ocean temperature and baroclinic mass transport is used to determine the transport through Drake Passage at the times of the sections. This technique is a powerful complement to more conventional means of data collection in this region, especially given the ability of the seals to conduct "sections" at times when ship-based fieldwork is logistically most challenging, i.e. in the winter time. The CTD-SRDLs do not only record hydrographic data, but simultaneously record seal movements and diving behavior. This enables insight to be obtained on the behavioral and physiological responses of Southern elephant seals to spatial environmental variability throughout their circumpolar range. The resulting energetic consequences of these variations could help explain recently observed spatially varying population trends. With a stable population at South Georgia and declining populations at Kerguelen and Macquarie Island. This study also highlights the benefits to the sensorcarrying animals themselves by showing the usefulness of this approach in examining the sensitivity of top predators to global and regional-scale climate variability. More importantly, I conclude that, by implementing animal-borne sensors into ocean observing strategies, we not only gain information about global ocean circulation and enhance our understanding of climate and the corresponding heat and salt transports, but at the same time we increase our knowledge about ocean’s top predators, their life history and their sensitivity to climate change.
94

The population dynamics of impala (Aepyceros melampus Lichtenstein) in Mkuzi Game Reserve.

Vincent, John. 18 September 2014 (has links)
The need to understand the dynamics of the impala population in Mkuzi Game Reserve arose during the early 1960's when it became clear that various factors were contributing to an overpopulation of the species in the reserve. Population management was recognized as being necessary and was carried out, but it was based on inadequate information. This study set out to establish a rational basis for future management. The social organization and behaviour of impala in Mkuzi were analysed and placed in perspective relative to the population dynamics. Two methods of counting the animals were used and a relationship obtained between the respective results. The distribution of impala within the reserve, both on a gross population basis and with respect to the various sex and age categories, was determined from sampling. In order to establish the age structure of the population, samples obtained from the control programme were used, and these were aged on the basis of molar wear. At the same time the proportions of young animals and the population sex ratios were obtained by field sampling. Using these data, life tables were constructed, from . which it was possible to interpret the behaviour of the population at the time of the study. However, caution should be exercised in extrapolating these results literally to the same population under different conditions. The study only provides guidelines for regular monitoring to be carried out. At the same time a more detailed study of the vegetation dynamics of Mkuzi Game Reserve is a priority so that the relationship between the animal and plant elements of the reserve can be properly analysed. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1979.
95

Differences in Basal Metabolic Rates, Heart Masses, and Hematocrits of Bats, Terrestrial Mammals, and Birds

Watanabe, Brett Kaoru 01 January 2014 (has links)
Bats are the only mammals capable of powered flight. In flight, bats consume up to 20 times more oxygen per hour than under basal conditions. This is twice the increase reported for running mammals of the same body sizes. Birds are the only other group of vertebrate capable of powered flight. By plotting morphological and physiological parameters against body mass for bats, terrestrial mammals, and birds, we can observe to what extent these parameters permit high rates of oxygen delivery necessary for flight. In this study we analyzed basal metabolic rate, heart mass, and hematocrit, and compared how differently they scale in the afore-mentioned groups. We found that larger heart masses are associated with the ability to fly; hematocrit values for birds change markedly with body size, while those for mammals and bats are nearly independent of body size; and that BMR scales differently in all three groups.
96

The determination of acceptable Hippopotamus (Hippopotamus, Amphibius, Linn.) densities in the Crocodile River, outside the Kruger National Park

Eksteen, J.J. January 1993 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree Master of Science in Quantitative Conservation Biology, 1993 / The aim of the study was to provide a basis for the determination of acceptable hippo densities along the Crocodile River, outside the Kruger National Park. Hippo densities have to be acceptable to land-user~, who suffer hippo damage, and to the conservation authority, responsible for the resources along the river. Hippo nllmbers and distribution in the study area were determined by using a combination of aerial census and ground count. The hippo population number was estimated at 88 animals. Hippo distribution was influenced by flow speed of water. No hippos were observed in river sections with steep gradients, (>6.0 m/km) , while major herds were observed at low gradients «3.5 m/km). A mean density of 0.6 hippo per km was calculated, with a maximum of 2,5 hLppoe Zkm at Kaapmuiden, next to the Kruger National Park. TPA Nature Conservation records on hippo complaints were analyzed, and no relationship between the occurrence of hippo damage and hippo density could be found. There were strong indications that hippo damage are caused by individual problem hippo , The majority of land-users (92 %) supported the conservation of hippos. The size of the area available to hippo was determined for distances of 5 kn. up- and downriver from the major hippo herds. hippo could move away from the river was 336 restriction when compared to the generally assumed hippo grazing range of 3.2 km. Hippo access to grazing was assessed by determining the effective grazing area. / MT2017
97

A eletroforese capilar para a separação das metalotioneínas da cianobactéria (Synechococcus PCC 7942) e de mamíferos / Capillary electrophoresis for the separation of cyanobacterial metallothionein (Synechococcus PCC 7942) and mammals

Vida, Ana Clara Felix 23 March 2011 (has links)
Metalotioneínas (MTs) são proteínas de baixa massa molecular, que tem como principal função a regulação dos níveis de metais nos organismos. A caracterização das MTs da cianobactéria Synechococcus PCC 7942 por eletroforese capilar foi feita em comparação com os padrões comerciais de MTs de rim de cavalo e de fígado de coelho. As MTs de mamíferos apresentam diferentes arranjos moleculares, classificadas em isoformas. Na aplicação da eletroforese capilar como metodologia analítica para a otimização da separação das isoformas existentes, foram investigados a influência da composição da solução eletrolítica, variações da voltagem, comprimento do capilar e diâmetro interno do capilar. Os perfis eletroforéticos das misturas das MTs purificadas a partir de rim de cavalo e fígado de coelho comparados com a de cianobactéria mostraram uma diferenciação no tempo de migração. Para a separação foram testados eletrólitos tais como fosfato, borato e TRIS-HCl, sendo que os melhores resultados foram obtidos com o tampão TRIS-HCl (70 mM, pH 8,2) com adição de 5% de metanol. A separação eletroforética foi testada em capilares de sílica fundida de 75 e 25 m d.i., comprimento de 40, 50 e 60 cm. As soluções das amostras em volume de 327 nL foram introduzidas por injeção hidrodinâmica. As diferenças de potencial testadas foram de 10, 15, 20 e 25 kV. As melhores condições de separação foram atingidas empregado TRIS-HCl com 5% metanol como solução eletrolítica, em capilar de 60 cm e diferença de potencial de 20 kV o que estabilizou a corrente de separação em 42 \'mü\'A. Os resultados mostraram que a eletroforese capilar mostrou-se eficiente para separação das MTs de mamifero e da Synechococcus devido às diferenças de carga e tamanho das moléculas / Metallothioneins (MTs) are low molecular weight proteins, which main functions are the regulation of metals levels in the body and detoxification. The capillary electrophoresis (CE) characterization of MT from Synechococcus cyanobacteria was attained by comparison with commercial standards of horse kidney and rabbit liver MTs. The influence of electrolyte, such as phosphate, borate and TRIS-HCl buffers on the separation performance were tested. Also, parameters such as voltage potential, capillary length and capillary inner diameter were investigated to attain optimized separation of mammal and Synechococcus MTs. The electrophoretic profiles of MTs revealed four abundant metallothionein isoforms for the horse kidney sample, one for rabbit liver MTII and two for cyanobacteria Synechococcus. The separation by CE of horse and cyanobacteria MTs mixtures differentiated two sets of signals, the first with four peaks corresponding to the horse sample and the last to Synechococcus. The mixture of rabbit liver MT and cyanobacteria MTs presented a first peak for rabbit MTII and a second for cyanobacteria. Tests were performed trying phosphate, borate and TRIS-HCl buffers, however the best results were attained with TRIS-HCl buffer (70 mM, pH 8.2) with addition of 5% methanol. Different capillary lengths of 40, 50 and 60 cm and two internal diameters of 75 and 25m were tested. Also, voltages of 10, 15, 20 and 25 kV were studied. The best experimental conditions were attained using a 60 cm long capillary, TRIS-HCl plus 5% methanol as electrolyte, the application of 20 kV which allowed maintaining a separation current of 42 \'mü\'A. Results demonstrated that capillary electrophoresis was efficient for separation of MTs of mammals from that of Synechoccocus due their differences on size to charge
98

Cobertura florestal e intensificação do manejo: desafios para manutenção de biodiversidade em mosaicos agroflorestais / Forest cover and management intensification: challenges for biodiversity maintenance in agroforestry mosaics

Cassano, Camila Righetto 02 December 2011 (has links)
Sistemas agroflorestais abrigam grande biodiversidade quando comparados a outros usos da terra e representam uma ferramenta importante para conciliar produção agrícola e conservação de recursos naturais em paisagens modificadas pelo homem. Esta tese é composta de três capítulos que sintetizam e ampliam o conhecimento a respeito da influência do manejo das agroflorestas e da cobertura florestal remanescente sobre a distribuição dos organismos e apontam ações visando a conservação de biodiversidade em mosaicos agroflorestais. No primeiro capítulo revisamos a informação científica publicada até 2008 sobre a diversidade da fauna e flora nativas nas agroflorestas de cacau do sul da Bahia. Com base nesta síntese, identificamos recursos chave presentes nessas plantações que se relacionam com a maior riqueza de espécies ou presença de táxons ameaçados e evidenciamos a importância da manutenção de florestas nativas em mosaicos agroflorestais. Finalizamos esta revisão com recomendações para um manejo adaptativo visando a conservação de biodiversidade em propriedades e mosaicos agroflorestais e levantamos questões para serem respondidas por estudos futuros. Nos capítulos 2 e 3, apresentamos dois estudos empíricos realizados a partir da amostragem de mamíferos por armadilhas fotográficas em 30 agroflorestas e remanescentes florestais adjacentes a nove delas. No segundo capítulo, construímos e testamos hipóteses que descrevem quais espécies de mamífero de maior porte com ocorrência na região devem ser positiva e negativamente influenciadas pela conversão de florestas em agroflorestas e como estas respostas diferenciais deveriam se refletir na estrutura, composição e diversidade das assembléias. O valor de conservação das agroflorestas é apoiado pela presença de espécies endêmicas ou ameaças de extinção e pela composição de espécies similar entre florestas e agroflorestas. Entretanto, ao identificar que espécies caçadas e mortas por retaliação são raras ou ausentes na nossa amostragem e que agroflorestas são menos usadas por espécies arborícolas e mais usadas por espécies exóticas do que as florestas, nós explicitamos porque o valor de conservação das agroflorestas deve ser visto com cuidado, destacando questões que podem contribuir para a viabilidade das populações de mamíferos de maior porte em paisagens agroflorestais. No terceiro capítulo, contrastamos a importância relativa da intensificação do manejo e da cobertura florestal do entorno sobre o uso das agroflorestas de cacau por mamíferos de maior porte. Nossos resultados indicam que, na paisagem de estudo, fatores diretamente e indiretamente relacionados à intensificação do manejo das agroflorestas são mais importantes para a distribuição das espécies de mamíferos do que a quantidade de florestas remanescentes no entorno. A taxa de registro de cães domésticos (fator indireto) teve efeito negativo sobre várias espécies de mamíferos, enquanto a redução da conectividade do dossel das agroflorestas (diretamente associada ao manejo do sombreamento) teve um efeito negativo sobre espécies arborícolas e a redução da altura do estrato herbáceo (diretamente associada à freqüência de roçagem) um efeito positivo pequeno sobre espécies generalistas. Por outro lado, nesse mosaico agroflorestal com grande quantidade de florestas nativas remanescentes, apenas as espécies generalistas responderam à variação da quantidade de florestas no entorno, sendo mais comuns em agroflorestas circundadas por menor quantidade de floresta. Assim, em mosaicos agroflorestais com elevada cobertura florestal, restringir os efeitos negativos decorrentes da intensificação do uso da terra, como o controle das populações de cães domésticos e das atividades de caça e o planejamento cuidadoso do sombreamento das agroflorestas, deve resultar em maiores benefícios para o uso das agroflorestas por mamíferos de maior porte do que alterações na configuração espacial dos remanescentes florestais. Entretanto, a importância da cobertura florestal em relação a intensificação do manejo deve aumentar em paisagens mais desmatadas. Em conjunto, os três capítulos desta tese mostram que o conhecimento científico atual pode embasar o desenho de práticas e políticas públicas para conciliar produção agrícola e conservação em mosaicos agroflorestais. Tais práticas devem ser continuamente avaliadas, contribuindo e sendo repensadas com o avanço do conhecimento científico / Agroforestry systems harbor high levels of biodiversity if contrasted to other land uses and represent an important tool to reconcile agricultural production and conservation in humanmodified landscapes. This thesis is composed of three chapters that synthesize and expand the knowledge on the influence of agroforest management and remaining forest cover on the distribution of organisms, and highlight practices aiming biodiversity conservation in agroflorestry mosaics. In the first chapter we review the scientific information published until 2008 on the diversity of native fauna and flora in cacao agroforests in southern Bahia. Based on this synthesis, we identify key agroforest resources associated with higher species richness or the presence of threatened taxa, and emphasize the importance of Forest cover maintenance in agroforestry mosaics. We end this review with recommendations to an adaptive management aiming biodiversity conservation on farms and agroforestry mosaics and consider issues to be developed by future studies. On chapters 2 and 3 we present two empirical studies based on photographic records of large mammals in 30 agroforests and forest remnants adjacent to nine of them. In the second chapter we constructed and tested hypotheses describing which mammals from the regional species pool should be positively and negatively influenced by the conversion of forest to agroforests and how these differential responses should change assemblage structure, composition, and diversity. The high conservation value of agroforests is supported by the presence of species of conservation concern, and a similar species composition between forests and agroforests. However, by identifying that hunted and persecuted species are rare or absent in our samples, and that agroforests are less used by arboreal species and more used by non-native species than forest, we explicit why the conservation value of agroforests should be viewed with caution and underline issues that should be addressed to improve the viability of large mammal populations in agroforestry mosaics. In the third chapter we contrast the relative importance of management intensification and surrounding forest cover for the use of agroforests by large mammals. Our results indicate that, in the studied landscape, factors directly and indirectly related to management intensification are more important to define large mammal distribution than the amount and spatial arrangement of surrounding forest cover. High domestic dog capture rate (an indirect factor) had a negative effect on several species, while low canopy connectivity (directly associated to shade management) was negative correlated to the distribution of arboreal species and lower herbaceous vegetation (directly associated to ground vegetation clearance) had a minor positive influence on generalist species. On the other hand, in this agroforestry mosaic highly covered by native forests, only generalist species responded (positively) to the decrease in surrounding forest cover. In agroforestry mosaics from highly forested regions, restricting the negative effects of land-use intensification, such as the control of domestic dog populations and overhunting, and the careful planning of shade management, is likely to bring greater benefit to large mammal use of agroforests than the spatial arrangement of forest remnants. However, the importance of forest cover relative to management intensification is likely to be higher as deforestation increases. The three chapters show that current scientific knowledge can already support policy and management practices to conciliate agricultural production and biodiversity conservation in agroforestry mosaics. Such practices should be continuously evaluated, contributing to and being supported by improvement of scientific knowledge
99

Uso de habitat e padrão de atividade de médios e grandes mamíferos e nicho trófico de Lobo-Guará (Chrysocyon brachyurus), Onça-Parda (Puma concolor) e Jaguatirica (Leopardus pardalis) numa paisagem agroflorestal, no Est / Habitat use and activity patterns use of large and medium size mammals and niche overlap of Manned-wolf (Chrysocyon brachyurus), Mountain-lion (Puma concolor) and ocelot (Leopardus pardalis) in a agroforest landscape, in São Paulo State

Ciocheti, Giordano 17 April 2008 (has links)
O presente trabalho visou analisar padrões de atividade e uso de habitats por mamíferos de médio e grande porte, bem como dieta e sobreposição de nicho trófico de espécies de felinos e canídeos, numa região fragmentada do estado de São Paulo. Na paisagem estudada, existem duas unidades de conservação de proteção integral com vegetação de cerrado e floresta semidecídua, além de fragmentos de floresta nativa (semidecídua) em propriedades privadas. As hipóteses gerais do trabalho são: em ambientes mais impactados, i. as espécies de mamíferos de médio e grande porte tendem a generalizar seu comportamento de uso de habitat e padrão de atividade e ii. predadores de topo de cadeia alimentar aumentam a competição por recursos alimentares. Para explorá-las, foram estudados, por meio de armadilhas fotográficas e triagem de fezes, os seguintes aspectos: a) a freqüência do uso de diferentes habitats por mamíferos de médio e grande porte; b) o padrão de atividade de mamíferos de médio e grande porte; c) a dieta e a sobreposição de nicho de três carnívoros de topo de cadeia alimentar: lobo-guará (Chrysocyon brachyurus), onça-parda (Puma concolor) e jaguatirica (Leopardus pardalis). As coletas foram distribuídas em sete fragmentos, onde existem fitofisionomias nativas - cerrado sensu stricto, cerradão e floresta semidecídua - e também reflorestamento com espécies de eucaliptos. Foram obtidas 165, fotografias, nas quais identificou-se 17 espécies. Foram coletadas e identificadas 233 amostras de fezes, sendo 93 de lobo-guará, 68 de onça-parda, 38 de jaguatirica, 30 de outros pequenos felinos e 4 de cachorro-do-mato. Os resultados mostraram que, de forma geral, os mamíferos de médio e grande porte utilizam a área como um todo; os mamíferos mais especialistas, como o tapiti (Sylvilagus brasiliensis), mantiveram sua preferência por um habitat específico. Testes de correlação de Spearman mostraram que algumas espécies mais suscetíveis a alterações antrópicas mostraram-se correlacionadas a áreas com maior tamanho e grau de conectividade. Em relação aos padrões de atividade, os dados indicam que as espécies estão generalizando o seu comportamento: espécies que tinham atividade em alguns períodos do dia estão permanecendo ativas também em outros períodos. Quanto à dieta, o lobo-guará foi a espécie que utilizou mais itens entre os carnívoros estudados, alimentando-se de aves, répteis, frutos, mamíferos de diversos portes e insetos. A onça-parda e a jaguatirica apresentaram uma dieta mais restrita, sendo que os mamíferos representaram 90% dos itens consumidos. Houve uma alta sobreposição de nicho trófico entre lobo-guará e jaguatirica, indicando competição entre essas espécies. Os resultados, obtidos tanto por meio de armadilhamento fotográfico como por análise da dieta, indicam que pode existir uma relação entre áreas com maior grau de conservação (áreas maiores, menos isoladas estruturalmente e imersas em matrizes mais permeáveis) e a freqüência de mamíferos, a sobreposição de nicho dos carnívoros de topo e a densidade de fezes encontradas / The following study analyzed activity patterns and habitat use of large and medium size mammals as well as diet and trophic niche overlapping of feline and canid species in a fragmented area of the State of São Paulo. The landscape studied contains two fully protected conservation units with cerrado and semi-deciduous vegetation and also remnants of native semi-deciduous forest located in private properties. The general hypothesis of this study are: in more impacted environments, i, large and medium size mammal species tend to generalize their behavior regarding habitat use and activity patterns and ii, top food chain predators increase the competition for resources. The following aspects were studied through photographic traps and fecal sorting: a) frequency of different habitat use by large and medium size mammals; b) activity pattern of large and medium size mammals; c) diet and niche overlapping of three top food chain carnivores: Chrysocyon brachyurus, Puma concolor and Leopardus pardalis. Samples were withdrawn from seven fragments of native phytophysiognomies - cerrado sensu stricto, cerradão and semideciduous forest - and from areas of eucalyptus plantations. One hundred and sixty five photographs were obtained, where 17 species were identified. Two hundred and thirty three samples of feces were collected and identified, of which 93 of Chrysocyon brachyurus, 68 of Puma concolor, 38 of Leopardus pardalis, 30 of other small felines and 4 of Cerdocyon thous. The results show that, generally, large and medium size mammals use the entire area. However, more specialist mammals, such as the Sylvilagus brasiliensis, kept their preference for a more specific habitat. Spearman correlation tests demonstrated that those species which are more susceptible to anthropic alterations were more correlated with areas containing a higher connectivity and bigger size. The data also indicated that species are generalizing their behavior regarding the activity patterns: species that were active in some periods of the day are now remaining active in other periods as well. Among the carnivore species studied, Chrysocyon brachyurus was the specie with the most diversified diet, feeding on birds, reptiles, fruits, insects and mammals. Puma concolor and Leopardus pardalis had more restricted diets, where 90% of the items ingested belonged to other mammals. The trophic niche of C. brachyurus and L. pardalis species were strongly overlapped, indicating competition between them. The results obtained through photographic traps and diet analysis indicate that there might be a relation between more conserved areas (less isolated larger areas immersed in more permeable matrixes) and the frequency of mammals, the overlapping niche of top food chain carnivores ad the density of feces found.
100

Factors affecting the survival, movements, and intraspecific relations during early life in populations of small mammals with particular reference to the vole

Godfrey, G. K. January 1953 (has links)
No description available.

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