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Although seldom reported, necrophagy is a relatively common phenomenon in nature. Among necrophagous vertebrates, scavengers are the only ones who have a diet composed almost exclusively by carrion. There are five species of scavengers recorded in Brazil and in some Brazilian regions these species can live in sympatry, interacting with each other and with species of Falconiformes. The aims of this study were: 1. to investigate the use of perches and food resources by necrophagous birds in different areas of Uberlândia city (MG), and 2. to establish the types of interactions (intra- and inter-specific) between the studied populations. The research was performed between December 2006 and December 2007, though field observations were concentrated in the dry period (June to September 2007). Three types of habitats were selected for the field work (urban environment, urban-rural environment and rural environment). The observations followed focal animal ad libitum analises, and were carried out from 9 am to 6 pm. All areas were sampled monthly, performing 90 hours of observation (30 hours in each area). Two species of necrophagous birds were recorded: Coragyps atratus (Black Vulture) and Caracara plancus (Crested Caracara). The rural-urban environment showed higher frequency of records of scavengers and Crested caracara using perches (5646). Moreover, the urban environment served as a deposit of waste and carcass of animals stemming both from urban environments as well as rural environments. Interactions for food were often marked by agonistic interactions, although there were displays which prevent disputes, such as warning postures and sounds production (including vocalization ). Interspecific allopreening was recorded at a higher frequency than expected and probably occurs as a way of rapprochement between Crested caracara and Black vultures when grouping in mixed flock. These mixed flocks seemed to be favored by the surveillance ability of the Crested caracara and because of its vocalization ability and thus producing scream of warning, useful for the flock. / A necrofagia é freqüente na natureza, embora seja um fenômeno pouco reportado para os vertebrados. Entre estes, urubus são os únicos que possuem uma dieta composta quase que exclusivamente de carcaças. No Brasil, são registradas cinco espécies de urubus e em algumas regiões brasileiras essas espécies podem viver em simpatria, interagindo entre si e com espécies de falconiformes. Os objetivos do presente estudo foram: 1. avaliar a utilização de poleiros e de recursos alimentares por aves necrófagas em diferentes áreas do município de Uberlândia (MG); e 2. estabelecer os tipos de interações (intra-específicas e interespecíficas) existentes entre as populações estudadas. A pesquisa foi desenvolvida entre dezembro de 2006 e dezembro de 2007, sendo que as observações de campo se concentraram no período de seca (junho a setembro de 2007). Foram selecionadas três áreas para realização do trabalho (ambiente urbano, ambiente rural-urbano e ambiente rural). As observações seguiram o modelo animal focal e ad libitum no objeto focal, tendo sido realizadas das 9 h às 18h. Em cada mês todas as áreas foram amostradas, totalizando 90 horas de observação (30h em cada área). Duas espécies de aves necrófagas foram registradas: Coragyps atratus (urubu-de-cabeça-preta) e Caracara plancus (carcará). A interface rural-urbana apresentou maior freqüência de registros de urubus e caracarás, quanto à utilização de poleiros (5.646). Adicionalmente, a franja urbana serve como depósito de lixo e carcaça de animais advindas tanto do ambiente urbanos quanto do ambiente rural. Interações alimentares são freqüentemente marcadas por interações agonísticas, embora haja indícios de displays que evitam disputas físicas tais como posturas de advertência e produção de sons, parecido com vocalização. Comportamento social interespecífico, Interspecific Allopreening , foi registrado em uma freqüência superior ao esperado e provavelmente ocorre como modo de aproximação entre caracarás e urubus na formação de um bando misto, que parece ser favorecido pela vigilância dos caracarás devido à sua capacidade de vocalização e, conseqüentemente, produção de grito de alerta. / Mestre em Ciências Veterinárias

Piscivorous birds are an integrated part of lake and coastline ecosystems. Despite decades of research it is yet unclear what influence fish eating birds have on the fish community. The aim of this literature study was to focus on how two fish eating birds, Great Cormorant and Great Crested Grebe, influence the fish community in shallow and eutrophic lakes. Different types of analysis methods have been used when doing research on the subject, including pellet analysis, stomach content analysis, tagging of fishes by “PIT”-techniques and analysis by observation. Results show that conclusions by studies tend to vary, but generally higher bird density, lower water temperature and a relatively high turbidity contribute to a higher influence on the fish community. Both bird species are opportunistic in their choice of food and catch prey of the species that occur locally. Both species also limit themselves in the prey size, but the choice vary over seasons because of water temperature and the birds requirements in association with breeding and migration. The significant level of influence seems to be when predation is conducted on younger and smaller fishes. The influence on the fish size can also be indirect, where predation on smaller individuals prevent fishes from becoming older and bigger. As studies tend to deviate in conclusion, no general answer to this issue can be given at present. Comprehensive research with several years of full control over both fish-and bird population is needed to find the proper conclusion.

This diploma thesis deals with submergence of low rectangular sharp-edged broad-crested weirs. From measurement of water levels in front of and behind of weir at different discharges and different weir heights, were determined values of submergence coefficient depending on relative height of submergence. From these values were determined the equation of submergence coefficient. Measured values were compared which results measurements, which are given in professional literature.

Dominance rank often determines the share of reproduction an individual male can secure in group-living animals (i.e. dominance rank-based reproductive skew). However, our knowledge of the interplay between individual and social factors in determining rank trajectories of males is still limited. The overall aim of this thesis was therefore to investigate mechanisms that underlie individual dominance rank trajectories in male crested macaques (Macaca nigra) and to highlight potential individual and social determinants of how males can achieve and maintain the highest rank possible. Data for this thesis were collected on 37 males during a field study on a natural population of crested macaques living in the Tangkoko-Batuangus Nature Reserve in Indonesia. In study 1, I validate Elo-rating as a particularly well suited method to quantify dominance hierarchies in animal species with dynamic dominance relationships. In studies 2 and 3, I suggest a personality structure for crested macaque males consisting of five distinct factors and further demonstrate that two personality factors determine whether males will rise or fall in rank. Finally, in study 4, I present results on how males utilize coalitions to increase their future rank. Together, these results shed light on how individual attributes and social environment both can impact male careers. Ultimately, in order to understand what determines rank-based reproductive skew, we need to consider the complexity and likely diversity of the mechanisms underlying rank trajectories of individual males which are likely to differ across different species.

It is suitable to add practical illustrations of hydraulic tasks during teaching hydraulics and hydrology. These practical illustrations can be realized by mobile hydraulic circuit which is situated in the auditorium. This thesis is focused on constructional and project solution of the circuit which consists of a compensatory tank with sufficient capacity, pump aggregate and hydraulic measure flume. The construction of hydraulic flume must enable quick, simple and safety installation of a scaled down models of a hydro technical structures. The main requirements of a mobile teaching circuit are clearness of practical hydraulic illustrations, compact dimensions, comparatively low weight, mobility and simple control and manipulation. This diploma thesis also includes design of a scaled down models of a hydro technical structures, especially set of plate weirs, bed-crested weir, ogee-crested weir, culvert, Venturi flume, sluice and radial gate, pier and roughened bed. The hydraulic circuit drawing part also includes instrument carrier with level gauge. This diploma thesis includes theoretical text part, technical report of designed objects, hydraulic calculations and drawing part.

This study is based in Tana River National Primate Reserve (TRNPR), Kenya. The reserve, established in 1976 to protect remnant patches of riverine forests from increasing human pressure is home to two endemic endangered primate subspecies, Tana River Red colobus (Colobus badius rufomitratus) and Tana River Crested mangabey (Cercocebus galeritus galeritus). Habitat encroachment through indigenous farming and forest uses was thought to be one of the causes of drastic colobus and mangabey population decline after 1975. This study aimed at; generating information on the impact of these human land-uses on the habitat, this would facilitate the preparation of management recommendations which would improve the chances of survival of primate habitats without compromising the welfare of indigenous people. Using 3 sets of aerial photographs and a geographic information system, information on land-use changes over time has been generated. A 3 month field work generated information on agriculture, forest uses and other relevant socio-economic information. Results from the study indicate that: (i) human population has increased by more than two-folds between 1969 and 1991; (ii) this has not corresponded to a net increase in forest area decrease or farm area increase; (iii) there has been a net increase in area under forest and decrease in area under agriculture; (iv) spatial and temporal changes in forest area explain colobus population crash observed between 1975 and 1985, (v) indigenous farmers interviewed prefer a compromise, where they are allowed controlled access to land within the reserve. They showed a keen knowledge of conservation costs and benefits and cause-effect processes between humans and the environment. Management recommendations advocate measures that encourage indigenous people to be partners in conservation.

This diploma thesis dealt with the influence of relative weir height of rectangular broad-crested weir on discharge coefficient. Based on the level measurement in front of weir for different heights of the weir P and discharges were determined values of discharge coefficient according h/P. These values were compared with the results of measurements and relationships, which are mentioned in the professional literature. In conclusion were derived new relationships that can be used to calculate the discharge coefficient relative to the overflow head.

The thesis deals with possibilities of numerical modelling of an overflow over selected types of auxiliary spillways and then the possibilities are verified in particular localities. In thesis, there is carried out the determination of capacity of selected spillways by using several methods: the calculation of the overflow equation, one-dimensional and two-dimensional numerical models and physical model. The author created parametric analysis to each single method. Parametric analysis represent various hydraulic conditions. Subsequently, there is possible to express the effect of parametric analysis. The author makes a comparison of water levels received by mentioned methods set out under the specific hydraulic conditions by calibration of each model with the physical model. Finally, author recommends values of all coefficients which have an impact on results of numerical modelling of the flow over selected types of weirs mostly using like auxiliary spillways.

Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.