Gut contents of 2,500 stonefly nymphs, comprising 10 species, from the Gunnison and Dolores Rivers, Colorado were examined from Dec., 1974-Oct., 1975. Perlidae species were carnivorous feeding primarily on chironomids, mayflies and caddisflies. Seasonal patterns of ingestion and preference varied among species and predator sizes and between rivers. Early instar polyphagous species utilized detritus in the fall, eventually shifting to carnivorous habits as they grew through winter-spring. Pteronarcids fed predominantly on detritus. Dietary overlap of predators was greatest in the Gunnison River, with subtle mechanisms such as prey species and size selectivity, temporal succession and seasonal shifts to detritus-plant material in some, providing reduction of competition. A more complete partitioning of prey resources was evident in the Dolores River.

Os objetivos do presente trabalho foram: estudar a estrutura, a distribuição e a variação sazonal da fauna hiperbêntica e simultaneamente avaliar os padrões de utilização do hiperbentos pelas espécies de peixes (jovens) e entender qual a importância da comunidade hiperbêntica na trofodinâmica da região estuarino-Iagunar de Cananéia. As coletas foram realizadas mensalmente com um \"refro beam-trawl\" modificado para o hiperbentos, tarrafa e rede de espera para os peixes, durante o período de outubro/83 a setembro/84 , em quatro locais do sublitoral (Arrozal, Batata I , Trincheira e Cardoso). As comunidades de peixes e de hiperbentos não mostraram padrões de distribuição espacial distintos nas quatro localidades. Tanto a comunidade de peixes como a hiperbêntica apresentaram variações sazonais com algumas diferenças; os peixes atingiram sua abundância máxima na primavera, 28,260/0-, no verão 24,26%, no outono 27,38% e no inverno 19,58%. A comunidade hiperbêntica variou de 30,04% na primavera, 19,81% no verão, 23,78% no outono e 26,37% no inverno; a riqueza específica e a abundância foram praticamente constantes durante o período de estudo e a estação mais rica foi a primavera. Os taxa do hiperbentos mais abundantes foram: Mysidacea, Bivalvia, Gastropoda, Copepoda, Caridea, Chaetognatha e Brachyura mostraram variação sazonal, sendo Mysidacea o mais abundante na primavera, Bivalvia no verão, Polychaeta no outono e Gastropoda e Polychaeta no inverno. A afinidade entre os espectros alimentares das espécies de peixe permitiu reunir os mesmos em 5 grupos diurnos e 2 noturnos. Os peixes do grupo I diurno, de amplo espectro alimentar, 20 itens, exploraram em 3 estações, exceto no verão, os taxa mais abundantes da comunidade hiperbêntica. Os peixes do grupo I noturno, também com espectro de 20 itens semelhante ao correspondente diurno, mas diferindo na constância de ingestão de Mollusca e a não exploração de Brachyura. Todos os outros grupos (II-V diurnos e \" noturno) tiveram espectros mais estreitos, entre 2 a 10 itens, com alguns itens básicos específicos. Os peixes jovens de Cananéia se caracterizaram por uma flexibilidade sazonal na exploração dos itens mais importantes do hiperbentos; partilha de diversos itens em comum, mas explorando em maior ou menor grau esse item; habilidade em explorar picos sazonais do hiperbentos e a onivoria de espécies dos grupos III-IV diurno e 11 noturno. A importância da comunidade hiperbêntica na alimentação desses peixes ficou evidente e confirmando, entretanto que deve-se ainda aprofundar este tipo de estudo, principalmente melhorando os aparelhos de coleta, para amostras com maior eficiência essa fauna tão específica como é a hiperbêntica. / During the period August 1983 to September 1984 monthly modified beam-trawl samples of hyperbenthos were collected simultaneously with cast and set nets samples of fishes at four sites of Cananéia lagoon estuarine region. The objectives of this study were to examine the structure, spatial distribution and seasonal variation of the hyperbenthos and evaluate the significance of this fauna on the diet of juvenile fishes inhabiting the sublittoral of Cananéia. Fish and hyperbenthic communites did not present distinct patterns of distribution but both seasonal variations in abundance. Fishes reached their largest abundance in Spring, 28.26%, in Summer 24,26%, in Autumn 27.38% and 19.58% in Winter. Hyperbenthos abundance varied from 30.04% in Spring to 19.81% in Summer, 23.78% in Autumn and 26.37% in Winter. Mysidacea, Bivalvia, Gastropoda, Copepoda, Caridea, Chaetognatha and Brachyura were the most abundant hyperbenthic taxon. The variation of predominant components was seasonal, Mysidacea in Spring, Bivalvia in Summer, Polychaeta in Autumn, Gastropoda and Polychaeta in Winter. The similarity verified among fish diets allowed to join fishes to 5 diurnal and 2 nocturnal groups. Fishes of group I (diurnal and nocturnal) revealed a wide similar feeding spectrum but the nocturnal group was distinguished for invariably ingesting Mollusca and not eating Brachyura. The other groups had a diet with fewer number of items, from 2 to 10, but each one showed a specific basic food item. The young fishes of Cananéia estuarine region may be characterized by their seasonal fIexibility of feeding habits, by sharing a common pool of food resources but exploiting each item with different intensity and by the omnivory of species of groups III-IV diurna and 11 nocturne. The role of hyperbenthos in the diet of juvenille fish species was recognized in Cananéia system. However, additional studies are required to explain the dynamics of hyperbenthos and the way resources are utilized by fish. Further investigation based on more effective gears of sampling near-bottom fauna - the hyperbenthos are needed to fully explain the role of hyperbenthos in the trophic ecology of Cananéia.

Os objetivos do presente trabalho foram: estudar a estrutura, a distribuição e a variação sazonal da fauna hiperbêntica e simultaneamente avaliar os padrões de utilização do hiperbentos pelas espécies de peixes (jovens) e entender qual a importância da comunidade hiperbêntica na trofodinâmica da região estuarino-Iagunar de Cananéia. As coletas foram realizadas mensalmente com um \"refro beam-trawl\" modificado para o hiperbentos, tarrafa e rede de espera para os peixes, durante o período de outubro/83 a setembro/84 , em quatro locais do sublitoral (Arrozal, Batata I , Trincheira e Cardoso). As comunidades de peixes e de hiperbentos não mostraram padrões de distribuição espacial distintos nas quatro localidades. Tanto a comunidade de peixes como a hiperbêntica apresentaram variações sazonais com algumas diferenças; os peixes atingiram sua abundância máxima na primavera, 28,260/0-, no verão 24,26%, no outono 27,38% e no inverno 19,58%. A comunidade hiperbêntica variou de 30,04% na primavera, 19,81% no verão, 23,78% no outono e 26,37% no inverno; a riqueza específica e a abundância foram praticamente constantes durante o período de estudo e a estação mais rica foi a primavera. Os taxa do hiperbentos mais abundantes foram: Mysidacea, Bivalvia, Gastropoda, Copepoda, Caridea, Chaetognatha e Brachyura mostraram variação sazonal, sendo Mysidacea o mais abundante na primavera, Bivalvia no verão, Polychaeta no outono e Gastropoda e Polychaeta no inverno. A afinidade entre os espectros alimentares das espécies de peixe permitiu reunir os mesmos em 5 grupos diurnos e 2 noturnos. Os peixes do grupo I diurno, de amplo espectro alimentar, 20 itens, exploraram em 3 estações, exceto no verão, os taxa mais abundantes da comunidade hiperbêntica. Os peixes do grupo I noturno, também com espectro de 20 itens semelhante ao correspondente diurno, mas diferindo na constância de ingestão de Mollusca e a não exploração de Brachyura. Todos os outros grupos (II-V diurnos e \" noturno) tiveram espectros mais estreitos, entre 2 a 10 itens, com alguns itens básicos específicos. Os peixes jovens de Cananéia se caracterizaram por uma flexibilidade sazonal na exploração dos itens mais importantes do hiperbentos; partilha de diversos itens em comum, mas explorando em maior ou menor grau esse item; habilidade em explorar picos sazonais do hiperbentos e a onivoria de espécies dos grupos III-IV diurno e 11 noturno. A importância da comunidade hiperbêntica na alimentação desses peixes ficou evidente e confirmando, entretanto que deve-se ainda aprofundar este tipo de estudo, principalmente melhorando os aparelhos de coleta, para amostras com maior eficiência essa fauna tão específica como é a hiperbêntica. / During the period August 1983 to September 1984 monthly modified beam-trawl samples of hyperbenthos were collected simultaneously with cast and set nets samples of fishes at four sites of Cananéia lagoon estuarine region. The objectives of this study were to examine the structure, spatial distribution and seasonal variation of the hyperbenthos and evaluate the significance of this fauna on the diet of juvenile fishes inhabiting the sublittoral of Cananéia. Fish and hyperbenthic communites did not present distinct patterns of distribution but both seasonal variations in abundance. Fishes reached their largest abundance in Spring, 28.26%, in Summer 24,26%, in Autumn 27.38% and 19.58% in Winter. Hyperbenthos abundance varied from 30.04% in Spring to 19.81% in Summer, 23.78% in Autumn and 26.37% in Winter. Mysidacea, Bivalvia, Gastropoda, Copepoda, Caridea, Chaetognatha and Brachyura were the most abundant hyperbenthic taxon. The variation of predominant components was seasonal, Mysidacea in Spring, Bivalvia in Summer, Polychaeta in Autumn, Gastropoda and Polychaeta in Winter. The similarity verified among fish diets allowed to join fishes to 5 diurnal and 2 nocturnal groups. Fishes of group I (diurnal and nocturnal) revealed a wide similar feeding spectrum but the nocturnal group was distinguished for invariably ingesting Mollusca and not eating Brachyura. The other groups had a diet with fewer number of items, from 2 to 10, but each one showed a specific basic food item. The young fishes of Cananéia estuarine region may be characterized by their seasonal fIexibility of feeding habits, by sharing a common pool of food resources but exploiting each item with different intensity and by the omnivory of species of groups III-IV diurna and 11 nocturne. The role of hyperbenthos in the diet of juvenille fish species was recognized in Cananéia system. However, additional studies are required to explain the dynamics of hyperbenthos and the way resources are utilized by fish. Further investigation based on more effective gears of sampling near-bottom fauna - the hyperbenthos are needed to fully explain the role of hyperbenthos in the trophic ecology of Cananéia.

Esta dissertação analisa os conteúdos e interesses presentes no processo de construção da noção de segurança alimentar da comunidade quilombola Maçambique, localizada no município de Canguçu, do estado do Rio Grande do Sul, a partir das ações de intervenções dos mediadores sociais, vinculados ao quadro de funcionários da empresa de assistência técnica e extensão rural - EMATER e do Centro de Apoio ao Pequeno Agricultor-CAPA. Parte-se do pressuposto de que esta elaboração oculta uma disputa entre estas duas instituições, em torno dos referenciais da “nova orientação” para as ações de Assistência Técnica e Extensão Rural no Brasil. Busca-se, a partir de dados empíricos, analisar as condições e estratégias de acesso aos alimentos pelos agricultores, que contribui para a formação simbólica deste referencial incentivada pelos mediadores sociais. Para isto, utiliza-se o conceito de arena, grupos estratégicos e mediação. Trata-se, portanto, de trazer para o centro da análise os conflitos, interesses e conteúdos presentes e um processo vivo de formação desta idéia, a partir da percepção dos diferentes agentes envolvidos. Nesse sentido, procurou-se identificar os saberes e práticas alimentares dos agricultores quilombolas, a partir de uma abordagem antropológica e social. São algumas dimensões empíricas que foram consideradas para o desenvolvimento das análises aqui postas. Assim, identificou-se que as estratégias usadas pelos agricultores na obtenção dos alimentos estão vinculadas a uma rede social, sustentada em princípios de reciprocidade, configurando uma relação didática. Também verificou-se diferentes conteúdos e interesses nas atuações dos mediadores neste processo, ocorrendo uma disputa em torno da percepção da segurança alimentar dentro da comunidade, polarizando duas teses: tecnificação versus exotização por parte dos mediadores. Chega-se a conclusão que estas duas orientações geram uma violência simbólica; além de uma relação de dominação entre mediadores e mediados. / This dissertation, analyzes the contents and interests present in the concept of alimentary safety, as a process of construction in a community quilombola Maçambique, localize in county of Canguçu, on the state of Rio Grande of South, base on work and interventions of the social mediators that belong to the group of workers of the company of attendance technique and extension rural-EMATER and to the Center of Support to Small Farmer-CAPA. It starts with the presupposition that this elaboration, hides one dispute among these two establishments, around of ideas about “the new orientation” for the actions of Attendance Technique and Extension Rural to the Brazil. It looks for, to begin, from empirical data, to analyze the conditions and strategies of accessing the foods by the farmers, which contribute for the formation of symbolic referent, motivate by the social mediators. For this, I use the arena concept of the groups strategic and mediation. So, it’s necessary to bring to the center of the analysis the conflicts, interests and contents present in one system, alive, on formation of that knowledge, to start with the perception of this different agents involved. On this sense, it wants to identify the knowledge and uses alimentary by the quilombolas farmers’, from one anthropological and social approach. They are some of the empirical dimensions that were taking into account for the developments of the analyses considered here. So, it recognizes that the strategies used by the farmers for obtained the foods; it’s connected to one social net, sustained in foundations of reciprocities, which configured one ‘diática’ relationship. Also it verified different contents and interests on the actuations of mediators’ on this process, occurring one dispute around the perception of alimentary safety inside the community that polarize two theses: technicality versus exoticism from the mediators. I arrived to the conclusion that this two guidance’s generate a symbolic violence, beyond one relationship of domination among mediators and mediated.

Elk (Cervus elaphus) and mule deer (Odocoileus hemionus) density and foraging behavior were monitored in conjunction with disturbance by livestock (cattle and sheep) from 1991 to 1993 at Deseret Land and Livestock property near Woodruff, Utah. Elk and deer densities declined by as much as 92% in response to introduction of livestock, while associated areas where livestock were absent did not show this response. Biting rates and bite sizes were estimated and used to determine instantaneous intake rate. These measures were similar between pastures with cattle present or absent in 1992 but differed in 1993 for bite rate and marginally so for instantaneous intake rate. Bite rate and bite size but not instantaneous intake rate showed significant differences among years when the data for both treatments were combined. My results indicated that livestock locally displaced wild ungulates but displacement occurred only while the livestock were present. Differences in elk foraging behavior were greater between years than between treatments, and instantaneous intake rate alone was viewed as an inaccurate indicator of potential reductions in fitness.

The behavioral ecology of the American Wigeon (Anas americana) was studied over its annual cycle in western Canada between 1974 and 1978. The objective of this work was to examine the cross-seasonal interactions of the biology and behavior of the wigeon as they underlie the evolution of its mating system. The wigeon was more herbivorous than any other dabbling duck studied so far and spent a considerable amount of time feeding in upland habitats. Vegetation was important in the diet year round but particularly from late summer through the winter. Plant seeds were a rich source of protein and carbohydrate early in the spring. During breeding stages animal foods were selected by wigeons, particularly females. Wigeons usually did not feed on small crustaceans and gastropods but selected larger aquatic insect foods. Relative to other Anas soecies, the wigeon has a goose-like bill whose structure facilitates feeding on upland and aquatic vegetation. With the evolution of this specialization, efficient surface-straining of small foods has been sacrificed. To increase food digestibility, wigeons altered gizzard grit composition and organ sizes. Through these mechanisms I have demonstrated how wigeons have been able to increase the efficiency of digestion.

The Meiolania platyceps is an extinct Meiolaniid turtle which resided in the Southern Hemispheres Gondwanaland regions. The specimen used for this project was from the Pleistocene and found on Lord Howe Island, Australia. The aim of the project was to study the neck vertebrae in order to determinethe feeding ecology of the species, whether it preferred finding food of the ground or from higher vegetation. Through the neck range of motion, information about the relationships of the species should also be found, this since both taxonomic suborders of turtles, the cryptodira and he pleurodira have very distinctive patterns of movement for retracting the head. To determine this, the method of photogrammetry was used to develop 3D models of the vertebrae that could be manipulated in order to determine range of motion of the neck. The neck was discovered to match neither the movement pattern of the cryptodira or the pleurodira but is more likely a form of stem turtle or stem crypodira. Regarding the feeding patterns the results proved more conclusive. The neck mobility seems to strongly favor feeding from the ground. Since the Meiolania platyceps remnants have been found on islands and dated to Pleistocene time, which was the time leading up to the latest iceage, these ground level eating habits would most likely favor a diet of grass or similar. / Meiolania platyceps är en utdöd Meiolaniid sköldpadda som levde på södra halvklotets Gondwanaland regioner. Skelettet som används för detta projekt var från pleistocen tid och hittades på Lord Howe Island i Australien. Syftet med projektet var att studera halskotorna för att avgöra ätmönstret för arten, huruvida födointag kom från marken eller från högre vegetation. Genom nackens rörlighet kommer även mer information om artens släktskap kunna fås eftersom båda underarterna av sköldpadda har tydliga rörelsemönster för att dra tillbaka huvudet under skalet. För att fastställa detta användes metoden fotogrammetri för att utveckla 3D-modeller av kotor som kunde manipuleras för att fastställa halsens rörlighet. Baserat på halsens rörelseförmåga verkar arten inte passa in på varken cryptodira eller pleurodira utan det är troligare att arten är en form av stam sköldpadda eller en stam cryptodira. För födovanorna var dock studien mer konklusiv. Nackens rörlighet verkar tydligt tyda på att arten föredrog att få sin föda från på eller nära marknivå. Då Meiolania platyceps återfunnits på öar och skeletten daterats till pleistocen tid, som var upptakten till den senaste istiden, känns det troligt att markätande födovanor tyder på en kosthållning som främst bestod av gräs eller dylikt.

The behavioral ecology of the American Wigeon (Anas americana) was studied over its annual cycle in western Canada between 1974 and 1978. The objective of this work was to examine the cross-seasonal interactions of the biology and behavior of the wigeon as they underlie the evolution of its mating system. The wigeon was more herbivorous than any other dabbling duck studied so far and spent a considerable amount of time feeding in upland habitats. Vegetation was important in the diet year round but particularly from late summer through the winter. Plant seeds were a rich source of protein and carbohydrate early in the spring. During breeding stages animal foods were selected by wigeons, particularly females. Wigeons usually did not feed on small crustaceans and gastropods but selected larger aquatic insect foods. Relative to other Anas soecies, the wigeon has a goose-like bill whose structure facilitates feeding on upland and aquatic vegetation. With the evolution of this specialization, efficient surface-straining of small foods has been sacrificed. To increase food digestibility, wigeons altered gizzard grit composition and organ sizes. Through these mechanisms I have demonstrated how wigeons have been able to increase the efficiency of digestion.

Diss. (sammanfattning) Skara : Sveriges lantbruksuniversitet, 2008. / Härtill 4 uppsatser.

Diss. (sammanfattning) Skara : Sveriges lantbruksuniv., 2002. / Härtill 4 uppsatser.