A study in the Lower North Island located Parenephrops planifrons (koura) at 73 sites out of 104 sites visited (appendix 1). There was a significant difference in habitat variables between the sites which had koura present and those where they were absent. Examples of sites are shown in Appendix 3. Habitat variables important for classifying koura habitat included riparian cover, predators, winter equilibrium temperature and presence of in-stream habitat in the form of vegetation, litter cover and the stream sequence composition. Regression trees built could accurately describe the data but the kappa statistic was low.

Nest success of dabbling ducks in the Prairie Pothole region of North America has been declining for the past 40 years in parallel with declines in duck populations. Low nest success seems to result from the combination of an extremely fragmented breeding ground in a human-dominated landscape with an abundant and expanding ii community of generalist nest predators. Studies that examined variables associated with nest vulnerability to predation have produced contradictory results, likely because of simplistic approaches, lack of spatio-temporal replication, use of artificial nests , and the effect of confounding variables. I attempted to clarify the equivocal findings of previous studies by using multiple regression to simultaneously examine the effect of several variables purportedly related to nest predation risk. I collected data on >1,800 dabbling duck nests and associated variables for 16 habitat patches (14 managed for duck production) during two nesting seasons in North Dakota. At the habitat patch level, early and late in each breeding season, I studied the relationship of nest success and upland area, nest density, predator abundance and richness, abundance of alternative prey for predators, and visual and physical obstruction provided by the vegetation . At the spatial scale of the nest and its neighborhood, I examined the likelihood of nest predation in association to nest initiation date, year, distance from nest to a wetland and to an edge, vegetation type at the nest, visual obstruction and heterogeneity of the vegetation around the nest, duck nest species , predator abundance, and presence/absence of 5 carnivorous predators at the nest habitat patch. Nest success was generally low and highly variable in time, and among and within habitat patches. I found no relationship between nest success and any of the variables measured at the patch scale. At the nest level, only initiation date, distance to water, visual obstruction, predator abundance, and duck species had an effect. High variability in the data and the lack of patterns in the relationship of nest predation and the predictor variables precluded me from building a predictive model that explains nest success. Nest success could not be predicted, predation was incidental and risk was high, and there were no safe nest sites for hens to choose in a landscape swamped by nest predators . Nests were located randomly; therefore, there were no clues predators could use to enhance their success in finding nests.

Puisque l’altération des habitats d’eau douce augmente, il devient critique d’identifier les composantes de l’habitat qui influencent les métriques de la productivité des pêcheries. Nous avons comparé la contribution relative de trois types de variables d’habitat à l’explication de la variance de métriques d’abondance, de biomasse et de richesse à l’aide de modèles d’habitat de poissons, et avons identifié les variables d’habitat les plus efficaces à expliquer ces variations. Au cours des étés 2012 et 2013, les communautés de poissons de 43 sites littoraux ont été échantillonnées dans le Lac du Bonnet, un réservoir dans le Sud-est du Manitoba (Canada). Sept scénarios d’échantillonnage, différant par l’engin de pêche, l’année et le moment de la journée, ont été utilisés pour estimer l’abondance, la biomasse et la richesse à chaque site, toutes espèces confondues. Trois types de variables d’habitat ont été évalués: des variables locales (à l’intérieur du site), des variables latérales (caractérisation de la berge) et des variables contextuelles (position relative à des attributs du paysage). Les variables d’habitat locales et contextuelles expliquaient en moyenne un total de 44 % (R2 ajusté) de la variation des métriques de la productivité des pêcheries, alors que les variables d’habitat latérales expliquaient seulement 2 % de la variation. Les variables les plus souvent significatives sont la couverture de macrophytes, la distance aux tributaires d’une largeur ≥ 50 m et la distance aux marais d’une superficie ≥ 100 000 m2, ce qui suggère que ces variables sont les plus efficaces à expliquer la variation des métriques de la productivité des pêcheries dans la zone littorale des réservoirs. / As freshwater fisheries become increasingly prone to habitat alteration, it is critical we identify the components of habitat that greatly influence fisheries productivity metrics. Using fish habitat modeling, we compared relative contributions of three types of habitat variables to explain variation in abundance, biomass and richness metrics, and identified habitat variables most effective at explaining these variations. During the summers of 2012 and 2013, fish communities in 43 littoral sites were sampled from Lac du Bonnet, a reservoir in southeastern Manitoba (Canada). Seven different sampling scenarios, consisting of different sampling methods, years and time periods, were used to measure relative abundance, biomass and richness metrics for all species combined per site. Three types of habitat variables were measured: local (i.e. within site), lateral (i.e. shore characterization) and contextual (i.e. position relative to landscape attributes) variables. Together local and contextual habitat variables explained on average 44% R2adj of the variation across fisheries productivity metrics, while only 2% R2adj of the variation was explained by lateral habitat variables. Specifically, macrophyte coverage, distance to tributaries ≥ 50 m wide, and distance to marshes ≥ 100,000 m2 ranked most significant across metrics, suggesting these habitat variables may be most effective at explaining variation in fisheries productivity metrics in the littoral zone of reservoirs.

Alterations caused by the edge effects in a fragment have direct influence over the fauna and can determine the composition and distribution of the small non-flying mammals assemblage in a landscape. This study had as aim of analyzing the edge effect over the structure of a small mammal assemblege and the circumjacent environment in a decidual forest fragment located in the southern limit of the Atlantic Forest, in the center state of Rio Grande do Sul. Five field phases were carried out, with an effort of 6360 trap-night, and 1060 pitfall-night, totalizing 78 captured individuals (99 captures), belonging to four species of rodents and two species of marsupials. The success of capture of live traps was 1.2% and of pitfall traps was of 2.3%. Rodents were responsible for 97.4% of all captures and marsupials, 2.6%. In pitfall traps, it was observed high abundance of rodents in the interior in relation to the edge. The Analysis of Multivariada Variance by Randomization showed that there is no significant difference in the composition of species in relation to distances of the edge, despite the Analysis of Principal Components has evidenced some trends, grouping the species in accordance to the distances where they had occurred more frequently. Thus, the assemblege of small mammals was dominated by a species of rodent, Oligoryzomys nigripes, which represented 73% of all captures, appearing in all distances of the edge, but mostly in the forest interior. On the other hand, marsupials appeared only in the interior of the fragment, being A. montensis registered from 130 m from the edge, seeming to prefer habitats with denser forest cover. By using MANOVA, and on the basis of the biotic and abiotic factors analyzed along the edge gradient, it was possible to establish different distances of penetration of the edge that had varied from 10 to 160 meters. The Congruence Analysis showed that environmental variables which best explained the distribution of small mammas in the gradient was the feeding resources, lianas, trees and canopy cover. Thus, species of small mammals seem to use the modified environment in accordance to their adaptations to the available micro-habitats in the gradient edge-interior, having a noticeable edge effect in the study area. / Alterações causadas pelos efeitos de borda em um fragmento têm influência direta sobre a fauna e podem determinar a composição e distribuição da assembléia de pequenos mamíferos em uma paisagem. Este estudo teve como objetivo analisar o efeito de borda sobre a riqueza e abundância de pequenos mamíferos e o ambiente circunjacente em um fragmento de Floresta Estacional Decidual localizado no limite sul da Floresta Atlântica, no centro do Rio Grande do Sul. Foram realizadas cinco fases de campo, com esforço amostral de 6360 armadilhas-noite, e 1060 armadilhas de quedanoite, totalizando 78 indivíduos capturados (99 capturas), pertencentes a quatro espécies de roedores e duas de marsupiais. O sucesso de captura para as armadilhas de metal foi de 1,2% e para as armadilhas de queda foi de 2,3%. Os roedores representaram 97,4% das capturas e os marsupiais 2,6%. Nas armadilhas de queda, observou-se maior riqueza e abundância de roedores no interior em relação à borda. A Análise de Variância Multivariada via Aleatorização mostrou que não houve diferença significativa na composição de espécies em relação às distancias da borda ainda que a Análise de Componentes Principais tenha evidenciado algumas tendências agrupando as espécies de acordo com as distâncias onde elas ocorreram com maior freqüência. Assim, a assembléia de pequenos mamíferos esteve dominada por uma espécie de roedor, Oligoryzomys nigripes, que representou 73% do total de capturas, aparecendo em todas distâncias da borda, embora com uma tendência a ser mais florestal. Por outro lado, os marsupiais apareceram apenas no interior do fragmento, ao passo que A. montensis foi registrado a partir de 130 m do início da borda parecendo preferir ambientes com cobertura florestal mais densa. Com base nos fatores bióticos e abióticos que foram usados para estimar o término da borda e início do interior do fragmento foi possível estabelecer, através da MANOVA, diferentes distâncias de penetração da borda que variaram de 10 a 160 metros. A análise de congruência mostrou que as variáveis ambientais que melhor explicaram a distribuição dos animais no gradiente foram os recursos alimentares, lianas, árvores e cobertura do dossel. Assim, as espécies de pequenos mamíferos parecem utilizar o ambiente alterado de acordo com suas adaptações aos micro-hábitats disponíveis no gradiente bordainterior.