Northern Goshawk breeding habitat was conceptualized and analyzed as a system composed of different sized components organized within a hierarchy. The organization of the hierarchy was asymmetric with smaller components nested within and subordinate to larger components. Components considered in the breeding habitat hierarchy of goshawks were nest tree, nest site, nest territory, foraging area, and landscape. Choice at any level within the hierarchy was contrasted with the next level in the hierarchy. Thus it was found that goshawks chose nest trees with a largerdbh (79.0 ± 4.4 cm) than the nest site average (43 ± 2.7 cm) (p=0.000036); the averagedbh of the nest site (43.2± 3.1 cm) was significantly larger than the territory (33.2± 1.9cm) (p=0.018). The nest territory when contrasted with random unoccupied locations in the landscape demonstrated a composition of a central site of trees with largedbh and fewer stems when compared with the surrounding forest. I hypothesize that this pattern reduces thepredation risk at the nest site. I investigated the nest site relative to the assumed foraging area (radius of 3000m; approximately 3000ha). Goshawks selected nest sites which were significantly further from young clear cuts (>10 ha). The average distance from a nest site to a recentclearcut greater than 10 ha was 1,350 m of the nest while for unoccupied sites the average distance was 770 m (p = 0.011). Finally, at the landscape level, areas of approximately 10,000 ha, goshawks on Vancouver Island were more abundant, had more nest sites, and had higher productivity per active nest in old growth forests (>120 years) than in either second growth (majority less than 80 years) or fragmented landscapes. The majority of goshawk prey, as determined though pellet analysis was red squirrel (69%). Red squirrels were equally abundant in second growth and old growth yet less abundant in fragmented landscapes. Despite similar abundance of their main prey item goshawks were not as abundant in second growth forests as in old growth forests. I conclude that the structure of second growth and fragmented landscape reduces the availability of key prey species and therefor the suitability of these landscape fpr goshawks is lower. / Graduate

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A range of behavioral strategies and sensory abilities allow animals to minimize costs involved in the search for food. Among the factors involved in the variation of foraging costs, the availability of resources represents a central role and it is recognized for modulating the animal home range. Some species of termites can exhibit characteristics that make the foraging process even more expensive. Species belonging to the genus Nasutitermes, for example, have an extra cost in foraging: in addition to build a network of tunnels to access resources, they have a large number of soldiers, a caste trophically dependent. In the present study: (i) we evaluated the foraging pattern in Nasutitermes aff. coxipoensis (Termitidae: Nasutitermitinae), including the searching strategy and the role of soldiers; and (ii) we analyzed whether colonies of this species responds to variations in the availability of food resources. Manipulative experiments were conducted in the field and in the laboratory to analyze the pattern of foraging in N. aff. coxipoensis. For this, 35 nests were transplanted into areas of dunes in Pirambu-SE. Seven plots were established in a continuous increament in the density of resources (sugarcane baits). Laboratory tests were conducted to examine the role of chemical signals (eg. trail pheromone) present in the sternal gland of workers and soldiers. During 10 consecutive days it was measured: the number of trails and tunnels, their total length, number of branches and the tunneling speed (cm/day). Data were analyzed using generalized linear models and mixed linear models. Nasutitermes aff. coxipoensis showed mainly nocturnal foraging. Soldiers were the first individuals to start the foraging, however, in established trails, the number of workers were always higher than soldiers. The number of active trails remained constant over the observation period, while the number of tunnels increased. In groups of soldiers and workers, the workers chose to follow the trail signals of soldiers. The number of trails, the total length and their branches decreased with increment of resource availability. The conversion of trails in tunnels increased in areas with higher resource density. Our results suggest that the costs involved in the production of soldiers in N. aff. coxipoensis seem to be compensated by their decisive role during the foraging process. Colonies of this species seem to optimize their foraging through a combined strategy of constructing trails and tunnels. In places with low resource availability, termites forage mainly on trails, avoiding to convert trails in tunnels. This strategy has not yet been reported in the literature. Thus, N. aff. coxipoensis presents strategies in order to optimize the foraging, minimizing costs involved in this process. These results can contribute to the key question about the evolution of termite foraging behavior, as well as to understand the mechanisms involved in the distribution patterns and structuring communities of these insects. / Uma gama de estratégias comportamentais e habilidades sensoriais permite aos animais minimizar os custos envolvidos na busca por alimento. Dentre os fatores envolvidos na variação dos custos de forrageio, a disponibilidade de recursos representa um papel central e é reconhecida por modular as áreas de uso dos animais. Algumas espécies de cupins exibem características que podem tornar o processo de forrageio ainda mais oneroso. Espécies do gênero Nasutitermes, por exemplo, apresentam gastos extras no forrageio, uma vez que além de construírem uma rede de túneis para acessar os recursos, ainda apresentam um elevado número de soldados, indivíduos troficamente dependentes. No presente estudo, avaliamos (i) o padrão de forrageio em Nasutitermes aff. coxipoensis (Termitidae: Nasutitermitinae), incluindo as estratégias de busca e o papel dos soldados; e (ii) analisamos se colônias desta espécie respondem à variação na disponibilidade de recursos. Experimentos manipulativos foram conduzidos em campo e em laboratório a fim de analisar o padrão de forrageio de N. aff. coxipoensis. Para isso, 35 ninhos foram transplantados em áreas de dunas, em Pirambu- SE. Foram estabelecidas sete parcelas em um contínuo de aumento da densidade de recursos (iscas de cana-de-açúcar). Testes em laboratório foram realizados a fim de analisar o papel dos sinais químicos (ex. feromônio de trilha) presente na glândula esternal de operários e soldados. Durante 10 dias consecutivos foram quantificados: o número de trilhas e de túneis, o comprimento total, o número de ramificações destes e a velocidade de construção dos túneis. Os dados foram analisados utilizando-se modelos lineares generalizados e modelos mistos. Nasutitermes aff. coxipoensis apresentou forrageio principalmente noturno. Soldados foram os primeiros indivíduos a iniciarem o forrageio, no entanto, em trilhas já estabelecidas, o número de operários foi sempre maior do que o de soldados. O número de trilhas ativas permaneceu constante ao longo do período de observação, enquanto o número de túneis aumentou de forma gradativa. Em grupos compostos por soldados e operários, os operários preferiram seguir os sinais de trilha dos soldados. O número de trilhas, o comprimento total e suas ramificações reduziram com o aumento da disponibilidade de recursos. A conversão de trilhas em túneis aumentou em locais com maior densidade de recursos. Nossos resultados sugerem que os custos envolvidos na produção de soldados de Nasutitermes aff. coxipoensis parecem ser compensados pelo seu papel decisivo no forrageio. Colônias desta espécie parecem otimizar o forrageio através de uma estratégia combinada de formação de trilhas e túneis. Em locais com baixa disponibilidade de recursos os cupins forrageiam preferencialmente em trilhas, evitando a conversão destas em túneis. Tal estratégia, ainda não foi relatada na literatura. Assim, N. aff. coxipoensis apresenta estratégias para otimização do forrageio, minimizando os custos envolvidos nesse processo. Os resultados deste estudo podem contribuir para a investigação de questões sobre evolução do comportamento de forrageio de cupins, assim como para desvendar os mecanismos envolvidos nos padrões de distribuição e estruturação de comunidades desses insetos.

Bumble bees (Bombus spp.: Apidae) are valuable pollinators of many crop and wildflower species. However, in some situations their potential is limited. Evaluation of, and management to improve bumble bee efficacy should include spatial information which is currently limited. Distance and direction determine the success of gene flow via pollen cross-over within and between plant populations at several scales. Studies of movement by bumble bees at large scales in semi-natural and intensively managed habitats are scarce. Few studies of bumble bee dispersal from the nest exist, particularly in relation to crops. At a small scale, directional rather than random movement between flowers has benefits for pollen flow. Results to date of directionality studies at small scales and their interpretation are inconsistent. The purpose of this thesis was to assess distances and directions moved by foraging bumble bees at a range of scales in two contrasting farm habitats in order to predict their pollination potential. A novel method was developed to mark automatically all the occupants of nests of bumble bees B. terrestris (L.) placed around a Lucerne seed crop Medicago sativa L. in New Zealand. Reobservation data from eight nests showed that of bumble bees which foraged within the crop, 81 % travelled ≤ 50 m and 56% ≤ 20 m from their nest. Results should be interpreted with extreme caution because fewer than 1 % of bumble bees marked at nests were reobserved in the crop. Because it was not established where the other 99% of the bumble bees went, foraging areas for nests could not be calculated as anticipated. Theories to explain the non-specificity of bumble bees to the crop include; resource depletion near nests, competition with honey bees in the crop, or an evolved strategy to disperse in order to minimise nest predation. Lucerne flowers contained a significantly lower concentration of sugar in nectar, and significantly fewer pollen grains than did those of purple loosestrife Lythrum salicaria L., a species on which bumble bees appeared to forage in preference Lucerne. The higher rewards offered by L. salicaria may have diverted bumble bees from the less-rewarding Lucerne crop. In a Norwegian meadow system, all foraging bouts by bumble bees B. lucorum (L.) within a patch of wood cranesbill flowers Geranium sylvaticum L. were random with respect to direction. This result is not consistent with predictions, based on optimal foraging theory, that movement should be directional to enable optimal pollen flow, and to avoid revisitation of just-emptied flowers by the pollinator. A medium-scale study of several bumble bee species moving between patches of northern wolfsbane Aconitum septentrionale Koelle in Norway revealed considerable loyalty by bumble bees to patches in which they were marked. In a different landscape-scale study (over 5 ha), several bumble bees exhibited a high degree of loyalty to areas in which they were marked (87% were reobserved ≤ 50 m from marking points). These restricted movement patterns are discussed in terms of potential pollen flow. Of 260 bumble bees marked, only five were recorded crossing between meadows, which could be a result of innate loyalty to small forage areas, an artefact of the sampling technique used, or forest boundaries acting as physical impediments to movement. In the future, spatial data of the type collected in this thesis will aid in the management of bumble bee populations to achieve both commercial and conservation goals. Spatial data can be applied to predict the optimal placement of artificially-reared nests, predict suitable isolation distances for pure seed crops, and aid in the positioning of supplementary forage sources and nest-site refuges.