Astacologic survey took place in ÚN Lipno and was conducted in time from 2012 till 2013. For the actual mapping of the occurrence of spiny-cheek crayfish, the locations of total 17 places were detected. These monitoring areas were carried out in two ways for collecting the samples. The trapping of all individuals was achieved with special instruments, like pots or traps by hands or with the help of nets. For the caught specimens of spiny-cheek crayfish, which were determined by sex, the length of carapace was measured and as well if possible, the postorbital carapace length was taken. Throughout the whole monitoring, 228 individuals of spiny-cheek crayfish were caught in the amount of 107 (47%) females (CL = 21.5 ? 7.3 mm) and 121 (53%) males (CL = 20.1 ? 5 mm). Another aim of this work was to demonstrate that crayfish figure in fish food menu. Catches of fish were carried out in two ways, using fishing rods or into the clutches. The stomachs and intestines contents were analyzed at caught fish samples. If the condition of the contents of stomachs or intestines were allowed, it was also identified, what kind of food it was. For our annual issues, were included mainly species of piscivor fish. Spiny-cheek crayfish were identified in the stomachs of two species of fish, namely perch and pike.

Signal crayfish (Pacifastacus leniusculus) is important invasive species in European freshwaters. Its influence on other freshwater organisms is well known from the literature, as well as direct and indirect impact on fish assemblages. This work was focused on the experimental evaluation of non-indigenous signal crayfish as a predator of salmonids compared to indigenous noble crayfish (Astacus astacus). Moreover, the possible importance of young-of-the-year signal crayfish as a prey for salmonids was assessed. There were carried out experiments using eggs and hatchings of grayling (Thymallus thymallus) as a prey for adult and subadult specimens of both, signal and noble crayfish. Next experiment used young-of-the-year signal crayfish as a prey for young-of-the-year of brown trout (Salmo trutta). Results showed that the danger of signal crayfish for grayling eggs is slightly higher. However, detected differences were surprisingly lower and in the majority of parameters even insignificant. In the case of grayling hatchings, was not detected any significant difference at all. The abilities of both tested species to prey on eggs and hatchings are therefore very similar, comparable. Even so, the effect of signal crayfish can be importantly higher in natural conditions because of its more dense populations, higher growth rate and fast maturation. In accordance to our findings, it is evident that brown trout has no so high effect of crayfish juveniles compared with crayfish effect on salmonids early developmental stages. Crayfish are therefore more likely able to limit salmonids than conversely.

La chasse – comme la prédation naturelle - induit des réponses comportementales par les individus chassés qui cherchent ainsi à éviter ou à reduire le risque. Il est en particulier fréquent d'observer un changement dans leur utilisation de l'espace, mais l'articulation et les déterminants des réponses aux différentes échelles spatiales restent mal compris. De même, s'il a été suggéré que ces modifications comportementales pouvaient affecter en cascade la végétation, cela reste à tester. Pour combler ces lacunes, j'ai, (1) étudié, dans un paysage agricole du sud de la France, une population chassée de chevreuils et leur utilisation des milieux ouverts risqués et des couverts boisés, au cours de périodes de risque contrasté ; (2) testé, sur une population canadienne de cerfs à queue noire dépourvue de prédateurs et exempte de chasse, l'influence d'une chasse expérimentale sur le comportement des animaux et sur la végétation. J'ai montré que les chevreuils répondaient à une augmentation du risque à plusieurs échelles spatiales. Ils réduisaient leur utilisation des habitats risqués, et dans certains cas se rapprochaient des couverts, de jour ces deux réponses étant couplées au niveau individuel. Le gradient paysager d'ouverture du milieu contraignait cependant les niveaux de réponses observées et les stratégies individuelles. Au Canada, j'ai observé un évitement de la zone chassée par les cerfs les plus sensibles à la présence humaine, corrélé à une diminution de l'abroutissement pour deux des quatre espèces de plantes étudiées. J'ai intégré ces résultats dans une discussion sur l'utilisation de la chasse pour gérer les populations d'herbivores et leurs impacts sur la végétation. / Hunting – similarly to natural predation – induces behavioural responses of hunted individuals which aims at avoiding or reducing risk. Particularly, changes in space use are frequently observed, but the articulation and determinants of these changes at multiple spatial scales are still poorly understood. Also, although it has been suggested that these changes might cascade on the vegetation, this remains to be tested. To fill these gaps, I (1) studied a hunted roe deer population living in an agricultural landscape in southern France where roe deer can find open risky habitats and woody covers; and (2) tested black-tailed deer behavioural response to an experimental hunt in a predator- and hunting-free population in the Haïda-Gwaii archipelago (BC, Canada). I also investigated the possible cascading effects on the vegetation. I showed that roe deer responded to increased hunting pressure at multiple scales, reducing their use of the risky habitats and, in specific situations, their distance to the nearest cover. At day-time those two responses were coupled at the individual level. Generally, landscape openness constrained individual responses and strategies. In the hunting-for-fear experiment conducted on Haida Gwaii, I found that only the deer less-tolerant to human disturbance avoided the hunting area. A simultaneous reduction in browsing pressure on two out of the four plant species monitored was found however. I integrated these results in a general discussion on the possible role of hunting as a tool to manage abundant deer populations and their impacts on the vegetation.

A predação de sementes, juntamente com a dispersão, é um dos principais fatores determinantes no recrutamento de novos indivíduos. Espécies de plantas que oscilam na produção de frutos e sementes podem influenciar os predadores e dispersores, alterando a resposta destes em anos de baixa ou alta oferta de recursos. A araucária (Araucaria angustifolia) é o principal elemento da Floresta Ombrófila Mista e as suas sementes, os pinhões, além de amplamente consumidas pela fauna, são uma importante fonte de renda para muitas famílias. Dentre os animais, os roedores são os principais predadores dessas sementes. O objetivo de nosso estudo foi avaliar a relação entre a abundância dos roedores, a disponibilidade de frutos zoocóricos e de sementes da araucária. Avaliamos também se a disponibilidade de sementes influencia nas taxas de remoção e dispersão da araucária. Realizamos o estudo em oito áreas (quatro nativas e quatro de plantação com araucária) na Floresta Nacional de São Francisco de Paula, nordeste do Rio Grande do Sul. Amostramos os roedores durante cinco noites consecutivas em cada estação do ano (abr/outono, jul/inverno, out/primavera e jan/verão). Para avaliar a produção, acompanhamos mensalmente, entre jan/06 a jan/07, todos os indivíduos frutificando ao longo de duas transecções em cada área. Avaliamos também a predação e dispersão de sementes da araucária entre os meses de mai/06 a ago/06. Nossos resultados demonstraram que as sementes da araucária são um importante recurso nas áreas, principalmente no inverno, período em que houve uma queda acentuada na disponibilidade de outros frutos no solo. A abundância dos roedores variou entre as estações do ano, sendo maior no inverno e menor no verão. A remoção de sementes variou entre as áreas nativas e plantadas e entre os meses. Encontramos uma menor remoção nas áreas plantadas, locais de maior disponibilidade de pinhões no solo. A sobrevivência das sementes também foi maior nessas áreas. Nossos resultados indicaram um padrão de predação variando de acordo com a densidade, com uma correlação negativa entre a produção de sementes e a remoção. Nos locais de maior abundância de roedores e maior disponibilidade de sementes encontramos uma menor taxa de remoção, sugerindo uma possível saciação dos predadores. Essa estratégia pode ter conseqüências para o recrutamento e conservação da araucária, bem como para a dinâmica de predação e dispersão, caso não ocorra um manejo dos impactos associados a essa formação, como por exemplo, a coleta das sementes para comercialização e a presença de gado nas áreas. / Seed predation, as well as dispersion, is one of the determinant factors involved in the recruitments of new plant individuals. Plant species that oscillate in their fruit and seed production may influence their seed predators and dispersers, changing their responses in years with high or low resource offer. Araucaria angustifolia is the main element of the Araucaria Forest. Its seeds are largely consumed by the fauna as well as by people, being an important income source for many families. Among the animals that feed upon this seed, the rodents are the main predators. The aim of this study was to evaluate the relation between rodent abundance and fruit availability as well as Araucaria angustifolia seed availability. We also evaluated if the seed production influences the rate of predation and dispersion of araucaria seeds. We conducted the study in the National Forest of São Francisco de Paula, in Rio Grande do Sul state, southern Brazil. In this area, eight forested study sites were selected, four of them were covered by native vegetation (Mixed Ombrophilous Forest) and four were planted with Araucaria. We sampled the rodents at each site during five consecutive nights in each season (autumn, winter, spring, summer). To evaluate the amount of fruit production, we recorded all fruiting individuals of two transects of each area once a month between Jan/06 and Jan/07. We also evaluated the araucaria seed predation and dispersion between May/06 and Aug/06. Our results showed that Araucaria seeds are an important resource in the area, mainly in winter, on which availability of other fruits on the ground was lower. The rodent abundance changed between seasons, being higher during the winter and summer. Seed removal changed between native and planted sites as well as along months. We found low removal rates in planted areas, where overall seed availability on the ground was higher. Seed survival rate was also higher in these areas. Our results indicated a pattern of seed predation changing according to seed density, with a negative correlation between seed production and removal. In areas with higher rodent abundance, we detected lower removal rates, which suggests predator satiation. Such strategy might have consequences for recruitment and conservation of A. angustifolia, as well as for the predation and dispersion dynamic, in case of inadequate management of this species. Additional impacts on seed numbers, such as seed harvest for commercialization and the presence of cattle should be considered in management projects.

x, 62 leaves : ill. ; 29 cm Notes Typescript Thesis (M.S.)--University of Oregon, 1987 Includes vita and abstract Bibliography: leaves 54-62 Another copy on microfilm is located in Archives

The composition and preferences of depth levels and habitats of pelagic fingerling was studied in the canyon-shaped Vír Reservoir during years 2009-2011. The perch (Perca fluviatilis) fingerling was dominant in all three years. The density of fingerling was above the mean in years 2009 and 2010. It was as many as 278 individuals in 100m3(mean is 52 individuals in 100m3). A marked fall on 1,9 individual in 100m3 was registered in 2011. Perch fingerling was mainly observed in metalimnion during the day and also at night, where concentration of oxygen was very low. The highest density of perch fingerling was observed in the middle part within longitudinal profile. A significant difference was found in food composition among the years with high density and low density of fingerling. A predation of carp (Cyprinus carpio) and bream (Abramis brama) was proved during the years with high density of fingerling.

The aim of this thesis was to find out the extent of the predation of the Eurasian Reed Warbler (Acrocephalus scirpaceus) during the laying period in the South Bohemian Region. The survey was done by means of artificial nests containing fake eggs. Additional goal of the thesis was to evaluate the factors that can influence the predation according to measured nest parameters, such as the distance of the artificial nest from free water surface, the depth of water below the nest and the distance from the nearest tree.

Predation and prey responses to predators in aquatic environment are reviewed with emphasis on non-lethal effect of predators on prey life history, antipredator behavior and related mechanisms. The review focuses on dragonfly larvae and other groups of prey with complex life histories, mainly anurans. The review is complemented by laboratory experiments examining the effects of varied food availability and predation risk on a selected species of dragonfly, Sympetrum vulgatum.

Orientador: Prof. Dr. Gustavo Muniz Dias / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Evolução e Diversidade, 2017. / A maioria dos organismos que habitam costões rochosos possui ciclos de vida com uma fase larval planctônica e uma fase adulta bentônica. Uma vez que a larva é liberada na coluna de água, esta pode ser transportada para regiões afastadas da costa ou se fixar próximo à sua fonte de origem. Para organismos incrustantes, a transição do ambiente pelágico para o bentônico ocorre através do assentamento e recrutamento larval, período em que os organismos recém-metamorfoseados se fixam nos substrato e estão altamente sujeitos ao estresse tanto biótico quanto abiótico. Por esse motivo, o período entre o estágio larval e o estabelecimento dos adultos é considerado crucial para a diversidade e estruturação das comunidades incrustantes. No litoral norte do Estado de São Paulo, a Baía do Araçá é uma enseada, constantemente exposta a ações antrópicas, estando ameaçada pela expansão eminente do Porto de São Sebastião. Uma vez que a baía engloba um gradiente de condições físicas da sua entrada até o seu interior é esperado que os impactos da expansão do porto sejam diferentes entre as regiões da Baía do Araçá. Desta forma, objetivo deste estudo foi avaliar como os processos físicos e biológicos afetam o assentamento e recrutamento na comunidade bentônica de organismos sésseis da franja do infralitoral na Baía do Araçá e avaliar se diferenças nesses processos ao longo do gradiente formado da entrada para o interior da baía e ao longo do ano resultam em comunidades incrustantes distintas. Avaliamos ainda os efeitos dos fatores abióticos e biológicos, na diversidade e estruturação de comunidades de recrutas da franja do infralitoral. Em geral, os fatores que mais contribuíram para diferenças entre as regiões estudadas foram a concentração de clorofila e turbidez, que influenciaram a dinâmica de assentamento e recrutamento. Já a disponibilidade larval de uma forma geral foi influenciada principalmente pelo oxigênio dissolvido na água do mar variando muito ao longo do período estudado e entre as regiões. Larvas de poliquetos foram mais abundantes no interior da baía no verão. Tanto assentados quanto recrutas de ascídias e briozoários foram mais abundantes na entrada da baía, enquanto organismos solitários como poliquetos foram mais abundantes no interior da baía. A influência da predação não diferenciou as duas regiões, mas ocorreu em uma escala menor, dentro de cada região, podendo ter colaborado para moldar a comunidade e diminuir a riqueza e a dominância da ascídia Didemnum psammatodes. A disponibilidade larval não foi um bom preditor do assentamento, nem do recrutamento na comunidade, sugerindo que processos pósassentamento mediados principalmente por fatores abióticos, também contribuem para a formação de comunidades distintas entre as regiões. Concluímos que os estágios iniciais de desenvolvimento das comunidades da franja do infralitoral e os fatores que as estruturam diferem ao longo do gradiente da entrada para o interior da Baia do Araçá. Essa heterogeneidade espacial pode explicar a alta diversidade já registrada na região. A eventual degradação de parte da Baía do Araçá causada pela expansão do Porto de São Sebastião poderá causar em perda de biodiversidade. / Most organisms that inhabit rocky shores have life cycles with a planktonic larval stage and a benthic adult phase. Once the larva is released into the water column, it can be transported to regions far from the coast or to settle close to its source. For fouling organisms, the transition from the pelagic to the benthic environment occurs through and larval settlement and recruitment, a period in which newly metamorphosed organisms attach to the substrate and are highly subject to both biotic and abiotic stress. For this reason, the period between the larval stage and the establishment of adults is considered crucial for the diversity and structuring of the fouling communities. On the north coast of the state of São Paulo, the Araçá Bay is constantly exposed to anthropic actions, being threatened by the eminent expansion of the Port of São Sebastião. Since the bay encompasses a gradient of physical conditions from its entrance until its interior, it is expected that the impacts of the expansion of the port are different between the regions of Baía do Araçá. Thus, the objective of this study was to evaluate how physical and biological processes affect the settlement and recruitment in the benthic community of sessile organisms of the infralitoral fringe in Baía do Araçá and to evaluate if differences in these processes along the gradient formed from the entrance to the interior of the bay and throughout the year result in distinct fouling communities. We also evaluated the effects of physical and biological factors, on the diversity and structure of communities of recruits in the infralittoral fringe. In general, the factors that contribute the most to differences between the studied regions were concentration of chlorophyll and turbidity, which influenced the dynamics of settlement and recruitment. The overall larval availability was mainly influenced by dissolved oxygen in sea water varying greatly over the studied period and between regions. Larvae of polychaete were more abundant in the interior of the bay in summer. Both settlers and recruits of ascidians and bryozoans were more abundant at the entrance to the bay, while solitary organisms as polychaetes were more abundant within the bay. The influence of predation did not differentiate the two regions, but occurred on a smaller scale within each region, and may have collaborated to shape the community and diminish the richness and dominance of the ascidian Didemnum psammatodes. Larval availability was not a good predictor of settlement or recruitment in the community, suggesting that post-settlement processes mediated primarily by abiotic factors also contribute to the formation of distinct communities. We conclude that the initial stages of community development at the infralitoral fringe and the structuring factors are different along the gradient of the entrance to the bottom. Such spatial heterogeneity in the scale of the bay may define the high diversity recorded at the Araçá bay. Therefore, the eventual degradation of part of the Araçá Bay caused by the eventual expansion of the Port of São Sebastião will necessarily imply loss of biodiversity.

Made available in DSpace on 2014-12-02T11:16:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-11Bitstream added on 2014-12-02T11:21:33Z : No. of bitstreams: 1 000799124_20151101.pdf: 111843 bytes, checksum: 2c6e3c190259c848ea94b2f4803d4d76 (MD5) Bitstreams deleted on 2015-11-03T14:39:16Z: 000799124_20151101.pdf,. Added 1 bitstream(s) on 2015-11-03T14:40:17Z : No. of bitstreams: 1 000799124.pdf: 1194967 bytes, checksum: c142b75364ce6451c42c56e71008f2ee (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / É amplamente sabido que os subsídios alóctones entram nas teias alimentares receptoras participando diretamente da dinâmica dos consumidores e indiretamente sobre as interações predador-presa. No entanto, este conhecimento se baseia em estudos feitos em florestas temperadas e por conseguinte ainda há lacunas no conhecimento dos sistemas tropicais, onde a abundância e variedade das presas é maior. Neste trabalho, buscamos descrever o efeito dos insetos aquáticos emergentes sobre a dinâmica predador-presa das teias alimentares terrestres presentes em zonas ripárias de uma floresta tropical. Para testar este efeito, utilizamos um desenho experimental de blocos aleatorizados. Deste modo, manipulamos a emergencia de insetos adultos de um riacho, utilizando um tratamento de exclusão com uma cobertura plástica sobre o riacho e um tratamento de controle, onde permitimos a emergência natural dos insetos para a terra. Amostramos os insetos aquáticos emergentes com armadilhas adesivas e os artrópodes terrestres (predadores, fitófagos, onívoros, detritívoros) usando diversos métodos. A abundância de insetos aquáticos emergentes foi cinco vezes menor no tratamento de exclusão do que no tratramento de controle, mas como esperado, não houve diferenças nas abundâncias de insetos alados terrestres entre os tratamentos; insetos terrestres foram três vezes mais abundantes que os insetos aquáticos emergentes. PERMANOVA revelou que a abundância de predadores terrestres foi afetada pelo tratamento de exclusão de subsídios, mas não a biomassa. No entanto, análises univariadas mostraram que apenas 11,5% dos taxons de predadores (Anyphaenidae, Araneidae e Theridiidae) diminuíram sua abundância no tratamento de exclusão e o 7,7% deles (Araneidae e Theridiidae) diminuíram sua biomassa na exclusão. A abundância dos fitófagos, detritívoros e onívoros não foi afetada pela exclusão de subsídios, mas a biomassa dos fitófagos ... / It is widely known that input of allochthonous subsidies in recipient food webs directly participate in the dynamics of consumers and indirectly on predator-prey interactions. However, this knowledge is based on studies from temperate forests, thus there is still a gap in the knowledge of tropical systems where the abundance and diversity of terrestrial prey is high. In this study, we investigate the effects of emergent aquatic insects on predator-prey dynamics of tropical terrestrial food webs. To test this effect, we excluded allochthonous aquatic insects using greenhouse type exclosures, and allowed emergence of insects through unmanipulated stream reaches using a randomized design. Emergent aquatic insects and terrestrial flying insects were collected through sticky traps. Terrestrial arthropods in shrubs and ground were collected manually in nocturnal and diurnal surveys, and were classified in predators, phytophages, detritivores and omnivores. The abundance of aquatic insects was five times lower in exclosures than control, but there was no effect of treatment on abundance of terrestrial fly insects; abundance of terrestrial insects were three times more abundant that aquatic insects. PERMANOVA revealed that abundance of terrestrial predators, but not their biomass, was affected by exclosure treatment. Univariate analysis show that only 11.5% of predatory taxa (Anyphaenidae, Araneidae and Theridiidae) decreased its abundance in exclosure treatment and only 7.7% of them (Araneidae and Theridiidae) decreased its biomass. Abundance of phytophages, detritivores and omnivores was not affected by treatments, but the biomass of phytophages increased six times in exclosure treatment. Despite the abundance and biomass of only few predators were affected by exclosure, we observed that predators overall derived more than 80% of N and C of aquatic prey. Our results demonstrate that allochthonous subsidies participate on terrestrial food web ...