The work of which this study is an account was carried out while the author was Deputy Leader of the British Ornithologists' Union Centenary Expedition to Ascension Island , from November 1957 to April 1959. The objects of the expedition were to investigate the general breeding biology of the resident tropical seabirds with a view to discovering how the timing of their breeding was controlled. In most temperate birds the controlling factors are changes in day-length, temperature, and availability of food; the particular interest of the eleven species at Ascension was that they were living in an environment with no seasonal change in day-length or climate, and apparently a uniform availability of food. The author was responsible for studies on three of these species, the White Booby Sula dactylatra, the Brown Booby Sula leucogaster, and the Fairy Tern Gygis alba. A few observations were also made on the ten or so pairs of the Redfooted Booby Sula sula which were present. The bulk of this study is an account of the comparative breeding biology of the White and Brown Boobies. The Fairy Tern is not closely comparable to them, and only those aspects of its biology relevant to the general problem (breeding, food, and moult) are dealt with, in an Appendix. The study is divided into nine sections, of which four deal with the breeding of the boobies, and three with other observations on the species' biology, vis, moult and food (both of which were found to have an important relation to the breeding biology), and behaviour, which had neither been fully described nor analysed before. Section I is introductory, the aims, scope, and methods of study being described, together with the habitat. Ascension Island lies roughly in the middle of the South Atlantic (8°S, 14°25'W). It is a peak of the Mid-Atlantic Ridge, triangular in shape, with sides of about eight miles, and rises from coastal plains to 2,800 ft in the middle. Its volcanic origin is clearly seen in the numerous extinct craters, ash-fielda, and lava-flows, which are little weathered by the uniformly warm and sunny climate and the continuous south-east Trade-winds. Vegetation is confined to the slopes above about l,000 ft. As a result of man's introduction of rats and cats, the seabirds are no longer found on the main island and, with the exception of the Wideawake Tern, are now confined to off-shore stacks and islets. The expedition's main work was therefore done on Boatswain-bird Island, a volcanic plug some 300 ft high and 400 yds, across, about 300 yds, off the south-east corner of Ascension. Only intermittent visits could be paid to this island, and the author spent about 130 days, spaced over 15 months, on it. Section II deals with the colonies and breeding seasons. There were 1200-1300 pairs of White Boobies breeding on Boatswain-bird Island, and one or two pairs elsewhere. 600-700 pairs of Brown Boobies bred at Ascension, of which about two-thirds were on Boatswain-bird Island and the reminder on small stacks. In both species there were clearly-marked peaks of laying, with intervening periods when the number of new clutches was very small. In the White Booty breeding appeared to occur annually (only one fun season was studied, but deductions were made about the preceding and following ones), in the Brown about every eight months (two full seasons were seen, and again deductions were made about others). In both species the time taken from laying of eggs to fledging of chicks was the same, six to seven months. Individuals of both species conformed to the breeding seasons of the population, and if out of phase for some reason, they had a longer or shorter "rest" period as necessary to bring them into phase again at the next season, these two discoveries at once suggested that external factors were modifying the birds' internal physiological cycles and controlling the time of breeding. What these factors might be is discussed later in the study, in the light of subsequent discoveries about the species' breeding biology. The two species differed not only in periodicity of casual cycle but also in the time of year at which laying took place. The periodicity was such, however, that every two years the Brown Boobies would lay at almost the same time as the White. The significance of this, and its possible relation to annual variation in oceanic conditions with their origin in the melting of the Antarctic ice, is discussed, together with published information about the species' breeding seasons in other parts of the world. Section III deals with clutch-size and incubation. Both species were found to lay two eggs, with very few exceptions, but only one chick was raised. Incubation is described, and the attentive spells at the nest analysed; the attentive spells of both species were found to be variable, those of the White Booby being about 48 hours and those of the Brown about 24 hours. This probably indicated a difference in the birds' feeding range (partly confirmed by a study of their food), important in the consideration of the two species' ecologlcal differences. Some desertions occurred during the study of attention spells, and the circumstances of these strongly indicated that the birds were experiencing difficulty in finding food, this view subsequently being supported by other events. In Section IV the feeding, care, and growth of the chick are described. Records of growth rates of both normal, and abnormal chicks were obtained, and these provided further evidence of the operation of a food shortage. Losses in weight and reductions of growth rate occurred in chicks of varying ages but at roughly the sane date, August and September 1958. The second chick of the clutch hatched about five days after the first and never lived more than two or three days. The curious circumstances of this are described the smaller chick was apparently expelled from the nest by the larger, and not starved to death as a result of the larger chick's more vigorous demands, as has been shown in some other species of birds. Experiments with twins were carried, out to investigate this situation further; the larger chick's ability to establish a supremacy was found to be so strong as to operate even when the difference in size between artificial twins was very small; and some parents were able to raise twin chicks at apparently the normal rate of growth for two weeks or more. Possible reasons for this striking behaviour amongst the chicks and its relevance to clutch size and breeding success are discussed. In Section V, breeding success is described. Both species had a low breeding success, and big losses of eggs and chicks of the White Booby occurred in August and September 1958, supporting the other evidence concerning shortage of food. In one area of the White Booty colony studied only 4.5% of the eggs laid gave rise to flying young, in another area the figure being 9%. In the Brown Booby 5% of the eggs laid gave rise to flying young in one season, while in the following season the figure was 13%; the difference here was probably due to shortage of food in the first season causing late deaths among chicks. Section VI deals mainly with moult in the White Booby. Less information was obtained about the Brown Booty but the procedure appeared to be the same as in the White; in view of the Brown Booby's shorter sexual cycle, however, more information than could be obtained would have been interesting. The sequence of primary moult was discovered when examining juvenile White Boobies which had returned to the island after a post-fledging dispersal. The change from juvenile to adult plumage took more than two years, the shedding and regrowth of the primaries, from the innermost outwards, occurring in three spaced concurrent cycles.

The study that I detail in the following thesis is a component of a three-part collaborative project to provide the U. S. National Park Service and Cape Cod National Seashore (CCNS) with data needed to inform management decisions for protection of the endangered northwest Atlantic Roseate Tern (ROST) during fall pre-migratory staging. This study was designed to address objectives related to hatch-year (HY) ROST behavior and survival in response to human and non-human activities and environmental variables at CCNS. Behavioral data showed that disturbance, specifically human and non-human activities, were related to increased HY ROST locomotion (flying and walking). We also found that environmental variables, including day of season and time of day were related to increased locomotion. Flock-level HY ROST begging behavior was decreased in the presence of human disturbance, but we did not see the same effect at the individual level. We found no evidence that the observed behavioral effect of disturbance resulted in decreased residency, recruitment, or staging duration of HY ROST at CCNS. Our work demonstrates that disturbance events around staging flocks have behavioral consequences, but it is unknown whether HY ROST behavioral responses to disturbances are great enough to impact survival after departure from CCNS. A conservative and proactive management strategy to minimize the potential for negative carryover effects on survival should limit ROST exposure to disturbance, particularly human activities, by exclosing staging sites between mid-July–mid-September to encompass the period of time when the highest number of ROST use CCNS. / Master of Science

Availability of suitable nesting habitat that is free of nest predators and provides access to adequate prey resources within commuting distance is a major factor limiting seabird populations. Caspian terns (Hydroprogne caspia) in western North America have shifted their breeding habitat from naturally occurring habitats in interior wetlands, lakes, and rivers to primarily human-created habitats in coastal bays and estuaries. This shift has brought Caspian terns into conflict with fisheries of conservation concern, in particular anadromous salmonids. Prior to the 2010 breeding season, three artificial islands were built in the Klamath Basin National Wildlife Refuge (NWR) Complex as alternative nesting habitat for Caspian terns currently nesting at the world's largest colony for the species, near the mouth of the Columbia River, Oregon. I investigated the efficacy of habitat creation (island building) and social attraction (decoys and recorded vocalizations) for establishing new breeding colonies in the Upper Klamath Basin, California. In 2010, approximately 258 pairs of Caspian terns attempted to nest on the new islands and raised an average of 0.65 fledglings/breeding pair; in 2011, 222 pairs attempted to nest and raised an average of 0.11 fledglings/breeding pair. Competition with California and ring-billed gulls (Larus californicus and L. delawarensis) for nesting space, gull predation on Caspian tern eggs and chicks, low water levels, and depredation by great horned owls (Bubo virginianus) were the primary factors limiting colony development and productivity, especially in 2011. The immediate response by Caspian terns to habitat creation and social attraction in the Upper Klamath Basin demonstrates that these can be effective restoration techniques to establish new breeding colonies where nesting habitat is a major limiting factor; however, continued management of other limiting factors (e.g., control of on-colony predators and competitors) will likely be necessary to promote the development of established, self-sustaining breeding colonies on these artificial islands. Efforts to conserve and restore seabird colonies can be compromised by low prey availability within foraging distance of the breeding colony. I used GPS telemetry to study the fine-scale foraging behavior of Caspian terns nesting at two newly established colonies and cluster analysis to discriminate behavioral states based on movement characteristics. Terns breeding at the Sheepy Lake colony spent less time at the colony (52% of the day) than terns breeding at the Tule Lake colony (74%). Caspian terns breeding at Sheepy Lake foraged more extensively than terns breeding at Tule Lake; the foraging trips of Sheepy Lake terns lasted longer (median = 186 min) and were longer-distance (27 km) compared to those of Tule Lake terns (55 min and 6 km, respectively). Between-colony differences in foraging behavior corresponded to 5% lower average body mass of breeding adults and significantly lower size-adjusted body mass of chicks at the Sheepy Lake colony compared to the Tule Lake colony. Proximity to high-quality foraging areas influenced the foraging behavior and parental care of breeding Caspian terns, which in turn had effects on nesting success. The successful use of GPS telemetry to study the fine-scale foraging behavior of Caspian terns represents a significant advance in our ability to investigate the foraging ecology of this species and other moderate-sized seabirds. / Graduation date: 2013

Made available in DSpace on 2014-12-17T14:16:35Z (GMT). No. of bitstreams: 1 JahamunnaAAB_DISSERT.pdf: 3202307 bytes, checksum: 3dba8e8a699fb43853402bc73b61686f (MD5) Previous issue date: 2012-02-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / O metotrexato (MTX) ? um f?rmaco amplamente utilizado no tratamento da psor?ase, mas o seu uso sist?mico ocasiona efeitos adversos. A administra??o cut?nea do f?rmaco proporciona o aumento de sua biodisponibilidade na regi?o da pele lesada. Para isso, ? fundamental que o f?rmaco apresente boa solubilidade na forma n?o ionizada para garantir a permea??o cut?nea. O presente estudo teve como objetivo a obten??o de complexos de inclus?o do MTX com a betaciclodextrina (-CD) e a associa??o com compostos hidrof?licos como a trietanolamina (TEA) e os pol?meros polietilenoglic?is (PEG 1500, 4000 e 10000; Polaxamer 407,hidroxipropilmetilcelulose (HPMC), polivinilpirrolidona (PVP) e ?lcool polivin?lico (PVA) para a obten??o de complexos tern?rios. Os estudos de solubilidade foram realizados utilizando os diagramas de solubilidade de fases. A associa??o da B-CD levou a forma??o de complexos do tipo linear com estequiometria 1:1M, com uma constante de associa??o de Kc= 1179,8 M-1 e o aumento na solubilidade aquosa foi de cerca de 15 vezes. Dentre os complexos multicomponentes, os melhores resultados foram obtidos com o uso da TEA e PVP. Os complexos em fase s?lida foram obtidos por liofiliza??o. A caracteriza??o f?sico qu?mica inclui a microscopia eletr?nica de varredura (MEV), difra??o de raios-X (DRX), infravermelho (IV), calorimetria explorat?ria diferencial (DSC), Termogavimetria (TG) an?lise quantitativa do f?rmaco e os ensaios de dissolu??o. Os resultados experimentais sugeriram a forma??o de complexos de inclus?o nos quais o f?rmaco est? disperso na forma amorfa. Os ensaios de dissolu??o comprovaram que tanto o complexo bin?rio -CD:MTX quantos os complexos tern?rios contendo os pol?meros hidrof?licos e a TEA levaram ao consider?vel aumento da velocidade de dissolu??o

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-25T22:57:37Z No. of bitstreams: 1 ArthurSergioAvelinoDeMedeiros_DISSERT.pdf: 3584160 bytes, checksum: 26597e2b07b420ab5217392c2e4409b8 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-27T22:30:41Z (GMT) No. of bitstreams: 1 ArthurSergioAvelinoDeMedeiros_DISSERT.pdf: 3584160 bytes, checksum: 26597e2b07b420ab5217392c2e4409b8 (MD5) / Made available in DSpace on 2016-04-27T22:30:41Z (GMT). No. of bitstreams: 1 ArthurSergioAvelinoDeMedeiros_DISSERT.pdf: 3584160 bytes, checksum: 26597e2b07b420ab5217392c2e4409b8 (MD5) Previous issue date: 2015-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A triancinolona (TRI) ? um importante corticoster?ide utilizado na terap?utica como anti-inflamat?rio e devido ? sua baixa solubilidade em ?gua, ? utilizada principalmente na forma de suspens?es injet?veis. A associa??o da triancinolona com ciclodextrinas e co-solventes foi realizada para solubilizar o f?rmaco e explicar as intera??es envolvidas. Os diagramas de solubilidade de fases mostraram que o f?rmaco foi solubilizado pelas ciclodextrinas atrav?s da forma??o de um complexo incrivelmente est?vel, com os melhores resultados obtidos com a aplica??o da randomil-metil-beta-ciclodextrina (RM?CD) (aumento de solubilidade de 161 vezes). O f?rmaco tamb?m foi solubilizado pelos co-solventes, com incremento de solubilidade de 1,4 e 6,7 vezes (trietanolamina, TEA, e N-metilpirrolidona, NMP, respectivamente). A aplica??o simult?nea dos dois solubilizantes ainda permitiu um aumento de solubilidade consider?vel, por?m diminuiu a quantidade final solubilizada e a afinidade entre f?rmaco e ciclodextrinas, o que permitiu uma maior quantidade de f?rmaco n?o complexado. Os estudos experimentais de resson?ncia magn?tica nuclear 2D-ROESY e te?ricos por modelagem molecular mostraram intera??es da TRI com as CDs por complexo de inclus?o, provavelmente entre a extremidade do anel A do f?rmaco e cavidade das CDs. Os complexos s?lidos bin?rios e tern?rios puderam ser obtidos por spray drying. Evid?ncias de forma??o de complexo em fase s?lida foram ainda mostradas atrav?s de FTIR, difra??o de raios-X e microscopia eletr?nica de varredura. Os estudos de dissolu??o mostraram que associa??es bin?rias e tern?rias apresentaram maior velocidade de dissolu??o em compara??o com o f?rmaco puro. Al?m disso, o complexo tern?rio TRI:RM?CD:TEA apresentou uma maior velocidade de dissolu??o do f?rmaco que o complexo bin?rio TRI:RM?CD. Portanto, devido ? maior solubilidade e velocidade de dissolu??o, os complexos bin?rios e tern?rios se apresentam como novos insumos com grande potencial para a aplica??o farmac?utica da triancinolona. / Triamcinolone is a relevant anti-inflammatory costicosteroid drug, used mainly by injectable suspensions due its poor water solubility. The association of triamcinolone with cyclodextrins and co-solvents (triethanolamine TEA and N-methylpirrolidone NMP) was held to solubilize the drug and explain the involved interactions. Phase-solubility diagrams showed that triamcinolone was solubilized forming incredible stable complexes with cyclodextrins, in which bests results were observed applying randomyl-methylated-beta-cyclodextrin (RM?CD) (161 fold on increased solubility). The co-solvents TEA and NMP also enhanced drug solubility 1.4 and 6.7 fold, respectively. The association of both co-solvents with CDs seems decreased complexation stability, but enables higher amount of uncomplexed drug. Experimental magnetic resonance 2D-ROESY and theoretical molecular modeling studies demonstrated TRI-CDs interactions and elucidated the structure of formed complex, which occurred due to the inclusion of ring A of TRI on CDs cavity. Physicochemical aspects of solid binary and ternary complexes prepared by spray drying were assessed by using FTIR, X-ray diffraction and SEM photographs. Dissolution studies showed that binary and ternary associations presented higher dissolution efficacy in detrimental to pure drug system. In addition, the ternary complex containing TEA and RM?CD allowed drug dissolution faster than binary complex with RM?CD. Therefore, given the higher solubility and drug dissolution rate, binary and ternary complexes are new raw materials with great potential for pharmaceuticals containing triamcinolone.

Following catastrophic exploitation throughout the North Atlantic, breeding seabird populations have begun to recover thanks to regulatory protection and restoration and management efforts. As bird populations increase, new challenges emerge, including overgrowth of vegetation that limits the open nesting habitat favored by most tern species. Though managers have used a variety of measures to reduce vegetation cover, these techniques have rarely been quantified or compared experimentally. During the summers of 2009 and 2010, I applied two different techniques, controlled burning and artificial weed barriers (muslin fabric and artificial turf) to experimental plots on Eastern Egg Rock and Outer Green Island, near-shore seabird nesting islands in mid-coastal Maine. I then monitored vegetation regrowth and use by nesting terns to assess the effectiveness of these techniques for opening and maintaining Common Tern nesting habitat during a full breeding season, comparing treated plots to vegetated control plots and existing tern nesting habitat. Burned areas did not remain open for the full nesting season, but regrew shortly after laying, leading to near-complete nest failure in these plots. Tern nest and fledging success was similar in weed barrier (1.37 chicks/pair) and untreated tern nesting habitat (1.38 chicks/pair) plots. Replacement of existing vegetation, tested at a limited scale on Outer Green Island, did not succeed. These three techniques represent only a small fraction of vegetation management techniques used throughout the North Atlantic region. Through literature review and consultation with North Atlantic colony managers, I collected information on vegetation management on 34 tern nesting islands between 33 and 55° N latitude and developed a summary of different vegetation control techniques used. I identified 14 technique types suitable for use in nesting colonies: i.e., that can be applied before and after (but not during) the nesting period of May-July, that do not cause destructive impacts to the surrounding ecosystem, and that involve materials and labor that can be transported to inaccessible offshore islands. Of these techniques, 8 created usable tern nesting habitat for a full breeding season, and the most successful techniques required constructing habitat over existing vegetation. The success of different methods depended heavily on the plant communities and soil types involved. In general, vegetation management options were more limited and less successful for elevated, rocky islands than for low, sandy islands. Often, techniques that successfully removed one species or group of species (i.e., perennial grasses) failed due to rapid colonization by other species (i.e., herbaceous annuals). This review of past and ongoing vegetation management techniques used on seabird nesting islands, including their costs, methods for application, and effectiveness, provides seabird managers a reference when evaluating current and future vegetation management programs.

The Gulf of Maine is a dynamic ecosystem with rapidly warming sea surface temperatures (SSTs), therefore it is vital to understand how species interactions vary over time and space. In chapter two, I quantify and compare dietary differences among four tern species, across seven islands in the region, over a 32-year period. Multivariate statistical analyses were employed to discern spatial and temporal differences in foraging ecology. Findings suggest there are significant differences between species and islands; however, only three prey species comprise the majority of chick diet for all terns and islands. The reliance on only a few prey items led to narrow foraging niches, potentially increasing their vulnerability to climate change, fisheries practices, or other localized disturbances. The third chapter characterizes long-term trends across nesting islands, describes within-season dietary phenology, and quantifies how warming SSTs may influence diet. Over time there was a declining trend in the occurrence of hake and increasing amounts of sand lance. In addition, hake and sand lance occur with higher frequency earlier in the season, while butterfish and “other fish” showed the opposite trend. Furthermore, results indicated that the within-season decline of hake occurs more rapidly in years with earlier spring thermal transition dates potentially indicating a phenological shift. Finally, warming SSTs were found to be negatively correlated with hake and positively correlated with the “other fish” prey group. Given projections of further warming in the region, understanding how the diet of these seabirds may be impacted in crucial to their conservation.

La recherche d’image est une thématique de recherche très active. Plusieurs approches permettant d'établir un lien entre les descripteurs de bas niveau et la sémantique ont été proposées. Parmi celles-là, nous citons la reconnaissance d'objets, les ontologies et le bouclage de pertinence. Cependant, leur limitation majeure est la haute dépendance d’une ressource externe et l'incapacité à combiner efficacement l'information visuelle et sémantique. Cette thèse propose un système basé sur un graphe de patrons, la sélection ciblée des descripteurs pour la phase en ligne et l'amélioration de la visualisation des résultats. L'idée est de (1) construire un graphe de patrons composé d'une ontologie modulaire et d'un modèle basé graphe pour l'organisation de l'information sémantique, (2) de construire un ensemble de collections de descripteurs pour guider la sélection des descripteurs à appliquer durant la recherche et (3) améliorer la visualisation des résultats en intégrant les relations sémantiques déduite du graphe de patrons.Durant la construction de graphe de patrons, les modules ontologiques associés à chaque domaine sont automatiquement construits. Le graphe de régions résume l'information visuelle en un format plus condensé et la classifie selon son domaine. Le graphe de patrons est déduit par composition de modules ontologiques. Notre système a été testé sur trois bases d’images. Les résultats obtenus montrent une amélioration au niveau du processus de recherche, une meilleure adaptation des descripteurs visuels utilisés aux domaines couverts et une meilleure visualisation des résultats qui diminue le niveau d’abstraction par rapport à leur logique de génération. / Image retrieval is a very active search area. Several image retrieval approaches that allow mapping between low-level features and high-level semantics have been proposed. Among these, one can cite object recognition, ontologies, and relevance feedback. However, their main limitation concern their high dependence on reliable external resources and lack of capacity to combine semantic and visual information.This thesis proposes a system based on a pattern graph combining semantic and visual features, relevant visual feature selection for image retrieval and improvement of results visualization. The idea is (1) build a pattern graph composed of a modular ontology and a graph-based model, (2) to build visual feature collections to guide feature selection during online retrieval phase and (3) improve the retrieval results visualization with the integration of semantic relations.During the pattern graph building, ontology modules associated to each domain are automatically built using textual corpuses and external resources. The region's graphs summarize the visual information in a condensed form and classify it given its semantics. The pattern graph is obtained using modules composition. In visual features collections building, association rules are used to deduce the best practices on visual features use for image retrieval. Finally, results visualization uses the rich information on images to improve the results presentation.Our system has been tested on three image databases. The results show an improvement in the research process, a better adaptation of the visual features to the domains and a richer visualization of the results.

Mémoire numérisée par la Direction des bibliothèques de l'Université de Montréal.

Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus) nest in large colonies on East Sand Island in the Columbia River estuary, the largest known colonies for the two species in the world. Both species of piscivorous colonial waterbirds have been identified as predators with a significant impact on the survival of juvenile salmonids (Oncorhynchus spp.) listed under the U.S. Endangered Species Act. To better understand and address issues related to seabird-fisheries interactions in the Columbia River estuary, I conducted studies related to the ecology, conservation, and management of these two species of piscivorous waterbirds. I evaluated the demographics and inter-colony movements of Caspian terns belonging to the Pacific Coast metapopulation, with special emphasis on two breeding colonies, one on East Sand Island in the Columbia River estuary and the other on Crescent Island in the mid-Columbia River, based on re-sightings of color-banded individuals. Apparent annual adult survival at both colonies was high, and age at first reproduction was greater than previously reported for the species. Colony site philopatry of breeding adults at both colonies was high; however, some individuals prospected for breeding colonies over much of the Pacific Coast region and moved to other colonies over distances of up to 3,000 km. Some terns from the large colony in the Columbia River estuary responded quickly to the availability of new colony sites as distant as 550 km from the estuary, and established successful breeding colonies within less than a year of the new sites becoming available. The Caspian tern colony on East Sand Island appears to be an important source colony for a number of smaller, less productive colonies distributed over an extensive area from the Salton Sea, California to the Copper River Delta, Alaska, an area with limited and ephemeral nesting opportunities. Environmental contaminants have been a conservation concern for wildlife in the Columbia River estuary, especially species that consume fish and are therefore likely to bioaccumulate persistent organic pollutants. I measured and compared levels of polychlorinated biphenyls (PCBs) in eggs and chicks of Caspian terns and doublecrested cormorants, as well as their primary prey fish types, at colonies on East Sand Island and farther up-river. Based on differences in tern and cormorant diet composition at the various study colonies, higher PCB levels in eggs and chicks were associated with diets dominated by resident freshwater and estuarine fishes. PCB levels in prey fish were positively correlated with lipid content; however, PCB levels in the livers of chicks were negatively correlated with chick fat scores, suggesting that chick fat reserves are a sink for ingested PCBs. Lower PCB levels in terns and cormorants from East Sand Island compared to colonies farther up-river reflected diets with a higher proportion of marine forage fishes at East Sand Island; marine forage fishes had lower average levels of PCBs than their resident freshwater and estuarine counterparts. In order to explore non-destructive techniques for managing nesting colonies of double-crested cormorants, I evaluated habitat enhancement and social attraction, two techniques that have proven effective for relocating Caspian tern colonies to sites where impacts on fish stocks of conservation concern would be minimal. Cormorants were attracted to nest and successfully raised young at test plots on East Sand Island and on islands in the estuary with a previous history of cormorant nesting or unsuccessful nesting attempts. On an island with no history of cormorant nesting or prospecting, however, no cormorants were attracted to nest. My results suggest that attraction of nesting cormorants using these techniques is dependent on the previous history of cormorant nesting or nesting attempts, the frequency and intensity of disturbance by potential predators, and the presence of breeding cormorants nearby. While habitat enhancement and social attraction have potential as methods for redistributing nesting cormorants away from areas where fish stocks of concern are highly susceptible to predation, successful establishment of new colonies using these techniques will likely require a focus on sites with a history of cormorant nesting. Findings from this dissertation raise some concerns over the management of Caspian tern and double-crested cormorant colonies on East Sand Island in order to redistribute parts of these colonies to alternative sites and mitigate the impact of those piscivorous colonial waterbirds on ESA-listed salmonids. East Sand Island has supported source colonies of piscivorous colonial waterbirds for many smaller colonies throughout the region and is close to an abundant and relatively uncontaminated food supply. Also, alternative colony sites that can substitute for East Sand Island are not readily apparent, especially for double-crested cormorants. Therefore, management of Caspian tern and double-crested cormorant colonies on East Sand Island to benefit Columbia Basin salmonids needs to proceed cautiously and reversibly because of the implications for the region-wide populations of these piscivorous colonial waterbirds. / Graduation date: 2012