Canada is the second highest producer of hydroelectric energy in the world. Nearly 50 of the hydroelectric reservoirs in the country have a capacity larger than 1 billion m3. Despite the great number and extent of hydropower developments in Canada and around the world, relatively little is known about how dams and their operations influence terrestrial and semi-aquatic wildlife. Reservoirs at northern latitudes are characterized by large fluctuations in water level, which create modified shorelines called drawdown zones. To evaluate the impact of these disturbances on amphibians and reptiles, I conducted visual encounter surveys at two sites in the drawdown zone of Kinbasket Reservoir, near Valemount, B.C. From April to August of 2010 and 2011, I documented the habitat use, reproductive phenology, and body condition of two amphibian species (Anaxyrus boreas and Rana luteiventris) as well as the growth, movements, diet, and distribution of one species of garter snake (Thamnophis sirtalis). At two sites in the drawdown zone, A. boreas and R. luteiventris were present for the duration of the summer and utilized several ponds for reproduction. The presence and abundance of Rana luteiventris eggs were generally associated with ponds that had higher mean temperatures, higher mean pH, and the presence of fish. In 2010, there was sufficient time for amphibian breeding and metamorphosis to occur before the reservoir inundated the drawdown zone, but low precipitation levels in that year led to desiccation of many breeding ponds. In 2011, high rainfall and snowmelt led to early inundation of breeding ponds, and thousands of tadpoles were presumably swept into the reservoir. Gravid Thamnophis sirtalis were found at just one of two sites in the drawdown zone, but both sites were frequented by foraging individuals of this species. Anaxyrus boreas appears to be the primary prey of T. sirtalis in the drawdown zone. An improved understanding of how the amphibians and reptiles at Kinbasket Reservoir have persisted in this highly disturbed environment may be vital to their conservation — the activation of a new generating unit at Mica Dam in 2014 will alter the pattern and timing of reservoir inundation for the first time since it was constructed 40 years previously. / Graduate

Habitat fragmentation potentiates biodiversity loss worldwide. Species preservation requires an integrated understanding of wildlife-habitat relationships; however, responses to habitat fragmentation may vary considerably as a function of the species ecological flexibility and the unique attributes of each fragment habitat. In this dissertation, I explore the behavioural and health ecology of an ecologically flexible primate, the ringtailed lemur (Lemur catta), occupying forest fragments in south-central Madagascar that differ in isolation, degree of anthropogenic pressure, and L. catta food resource structure. Anja Special Reserve is a 34 ha rocky-outcrop forest fragment that is highly isolated from other forests containing L. catta. L. catta in this reserve have access to abundant food and water resources year-round due to the introduction of non-native fruit trees and the construction of an artificial lake adjacent the reserve, which support a population density of L. catta (6.6 lemurs/ha) that is higher than at any other site in which the species has been studied. In comparison, the Tsaranoro Valley forest is a 53 ha rocky-outcrop forest fragment that is surrounded by a matrix of grassy savannah and a few anthropogenic crops. While land clearing is pronounced in the valley, a few fragments remain within range for L. catta dispersal. L. catta in this fragment have limited access to introduced or anthropogenic resources and the population density (1.13 lemurs/ha) is one-sixth that at Anja. During the late dry season of 2010 and mid- to late-wet season of 2011, I collected continuous time focal animal data to examine behavioural patterns related to habitat use (ranging, matrix use, terrestriality), activity budgets, and feeding ecology of L. catta in each fragment. In addition, I examined two health parameters, stress and endoparasitism, through the collection of fecal samples from focal individuals. I compared these variables between and within populations to examine the potential impacts of habitat fragmentation on an ecologically adaptable primate. L. catta at Anja depended on smaller home range areas and a focused diet consisting largely of introduced food resources, and correspondingly exhibited lower energy expenditure, while spending more time engaging in rest and social acitivities when compared with the Tsaranoro lemurs. In comparison, L. catta at Tsaranoro occupied large home ranges, traveled greater distances to forage in the matrix habitat surrounding the fragment, and exhibited a more broad-based dietary strategy that contained few introduced or anthropogenic resources. From a health perspective, L. catta at Anja exhibited higher stress levels throughout the study period, while L. catta at Tsaranoro exhibited a greater prevalence of endoparasites, which may be reflective of differences in the social pressures and ranging patterns of L. catta between the two fragments, respectively. These results illustrate differences in the quality of the habitats and the potential fitness consequences that the L. catta populations must cope with, with important implications regarding the long-term suitability of these fragments for sustaining these populations. Such information is integral when assessing the viability of wildlife populations in degraded landscapes and should be a primary consideration for wildlife managers in biodiversity conservation. / Graduate / 0327 / 0329 / denisegabrie@gmail.com

In this thesis, I describe the behavioural ecology of an Australian passerine, the Southern Emuwren Stipiturus malachurus (Maluridae). The southern emu-wren is threatened in several parts of its range, and yet information on the species’ breeding biology, habitat use and mating system is lacking. These data are fundamental to effective conservation management. My research investigated the breeding behaviour and habitat ecology of a population of southern emu-wrens in Portland, Victoria, Australia, over three breeding seasons (2000/01, 2001/02 and 2002/03). also collected data pertaining to habitat use from populations located in Anglesea and Lower Glenelg National Park (Victoria, Australia). Southern emu-wrens commonly formed socially monogamous pair bonds, although cooperative breeding was observed for the first time in this species, where male offspring within several families delayed breeding to help raise younger siblings. Successful nests produced 1.8 fledglings on average, however, a nest had only a 56% chance of success during incubation and nestling phases. Nest failure was mainly attributed to depredation and snakes were identified as major nest predators. The slow breeding rate of the southern emu-wren is typical of a small passerine in the Southern Hemisphere. Nevertheless, adult mortality was unusually high. In one breeding season the adult population was reduced by 50%. The population recovered when individuals dispersed from the adjacent coastal heathland to fill territory vacancies. This highlights the vulnerability of populations to local catastrophe, and potential extinction if spatial separation of populations exceeds the species’ dispersal capacity.

A study of the aquatic invertebrate communities from two locations (Location 1 and Location 2) within the Matapouri catchment in Northland, New Zealand, was conducted to assess community structure in differing local-scale habitats. Four data collection methods were utilised generating 33,058 adult or larval invertebrates. The sampling methods comprised benthic kick-sampling, sticky trapping, light trapping, and emergence trapping. For the sticky trapping and light trapping, sampling was carried out at three different sites (Sites 1–3) within each location. The sites were situated within three habitat types; native forest, native forest-fringe, and raupo wetland. Emergence trapping also commenced within the three sites, at both locations, but was discontinued after two months, due to the equipment being destroyed by consecutive flooding events (method described in Appendix 1). Benthic sampling was carried out within the Forest and Forest-fringe habitats. Benthic sampling, sticky trapping, and light trapping were carried out following a monthly schedule between June and November 2005. Conductivity, pH, and water temperature measurements were taken concurrently with benthic sampling on a monthly basis, while water velocity and substrate measurements were taken once to assist in habitat characterisation. Overall, 71 taxa were recorded by benthic sampling over the six month period, with a mean of approximately 30 taxa per site per month. In comparison with similar studies elsewhere in New Zealand, a figure of around 30 taxa per sample was high. The benthic macroinvertebrate fauna at all sites was dominated by Trichoptera (19 taxa), Diptera (16 taxa) and Ephemeroptera (10 taxa). This pattern of diversity is similar to that reported in other New Zealand studies. However, in contrast to previous studies, the leptophlebiid mayfly genus Deleatidium was not numerically dominant over the rest of the community, and other leptophlebiid genera (Acanthophlebia, Atalophlebioides, Mauiulus and Zephlebia) were equally represented, possibly reflecting niche partitioning between the groups. The genus Nesameletus was not recorded at any site, despite being one of the core mayfly species in New Zealand streams. The rare mayfly Isothraulus abditus was recorded at one of the forest locations. There are no published records of this species from Northland. Although acknowledged as another of the core New Zealand benthic taxa, the hydropsychid caddisfly Aoteapsyche was not recorded during the study. However, another hydropsychid, Orthopsyche, was commonly recorded, and these may be filling a similar niche to the Aoteapsyche genus. In contrast to the Trichoptera, Diptera, and Ephemeroptera, the Plecoptera fauna was relatively depauperate, probably reflecting the warmer climate of the region and lack of temperature-buffered spring-fed streams. Surprisingly, Zelandobius, a core New Zealand genus, was absent but is regularly recorded in Northland. A species of conservation interest, Spaniocercoides watti, currently recognised as a Northland endemic, was recorded in low numbers. There were no apparent trends in diversity or abundance of benthic invertebrates over time. Also, there were no significant differences in species diversity between the two locations. However, in many cases, taxa were more abundant at Location 2. This may have been due to steeper gradients at Location 2, and the consequent effects on substrate size and streambed stability, as all other physical factors appeared similar between locations. Although several significant differences of individual benthic taxa were recorded, no broad effect of habitat (sites) on species diversity was observable. However, at Location 2, abundances were significantly higher at Site 3 (Forest) compared to Site 2 (Forest-fringe). The reasons were uncertain, but may be attributed to higher retention of allochthonous organic materials, trapped by in-stream cover and larger substrates. Investigations of adult stages by sticky traps supported benthic results recording community compositions and abundances dominated by Trichoptera and Diptera. Plecoptera were poorly represented. Location 2 recorded higher abundances of taxa, particularly Ephemeroptera and Plecoptera. Investigations of adult stages by light traps however did not produce any statistically significant differences in abundances between sites, between locations, or between sites across locations, and it is believed to be due to limited sampling replication combined with some biases of light trapping. This study indicates that the aquatic invertebrate community at Matapouri is diverse but also reasonably representative. Several rare or uncommon insects inhabit the catchment. It is therefore important that Iwi and the local Landcare Group, who invited and supported this research, together with the Department of Conservation, continue their efforts in protecting these areas. The resident fauna have the capacity to restock areas downstream, which are intended to be improved and restored through sediment control and riparian management.

A study of the aquatic invertebrate communities from two locations (Location 1 and Location 2) within the Matapouri catchment in Northland, New Zealand, was conducted to assess community structure in differing local-scale habitats. Four data collection methods were utilised generating 33,058 adult or larval invertebrates. The sampling methods comprised benthic kick-sampling, sticky trapping, light trapping, and emergence trapping. For the sticky trapping and light trapping, sampling was carried out at three different sites (Sites 1–3) within each location. The sites were situated within three habitat types; native forest, native forest-fringe, and raupo wetland. Emergence trapping also commenced within the three sites, at both locations, but was discontinued after two months, due to the equipment being destroyed by consecutive flooding events (method described in Appendix 1). Benthic sampling was carried out within the Forest and Forest-fringe habitats. Benthic sampling, sticky trapping, and light trapping were carried out following a monthly schedule between June and November 2005. Conductivity, pH, and water temperature measurements were taken concurrently with benthic sampling on a monthly basis, while water velocity and substrate measurements were taken once to assist in habitat characterisation. Overall, 71 taxa were recorded by benthic sampling over the six month period, with a mean of approximately 30 taxa per site per month. In comparison with similar studies elsewhere in New Zealand, a figure of around 30 taxa per sample was high. The benthic macroinvertebrate fauna at all sites was dominated by Trichoptera (19 taxa), Diptera (16 taxa) and Ephemeroptera (10 taxa). This pattern of diversity is similar to that reported in other New Zealand studies. However, in contrast to previous studies, the leptophlebiid mayfly genus Deleatidium was not numerically dominant over the rest of the community, and other leptophlebiid genera (Acanthophlebia, Atalophlebioides, Mauiulus and Zephlebia) were equally represented, possibly reflecting niche partitioning between the groups. The genus Nesameletus was not recorded at any site, despite being one of the core mayfly species in New Zealand streams. The rare mayfly Isothraulus abditus was recorded at one of the forest locations. There are no published records of this species from Northland. Although acknowledged as another of the core New Zealand benthic taxa, the hydropsychid caddisfly Aoteapsyche was not recorded during the study. However, another hydropsychid, Orthopsyche, was commonly recorded, and these may be filling a similar niche to the Aoteapsyche genus. In contrast to the Trichoptera, Diptera, and Ephemeroptera, the Plecoptera fauna was relatively depauperate, probably reflecting the warmer climate of the region and lack of temperature-buffered spring-fed streams. Surprisingly, Zelandobius, a core New Zealand genus, was absent but is regularly recorded in Northland. A species of conservation interest, Spaniocercoides watti, currently recognised as a Northland endemic, was recorded in low numbers. There were no apparent trends in diversity or abundance of benthic invertebrates over time. Also, there were no significant differences in species diversity between the two locations. However, in many cases, taxa were more abundant at Location 2. This may have been due to steeper gradients at Location 2, and the consequent effects on substrate size and streambed stability, as all other physical factors appeared similar between locations. Although several significant differences of individual benthic taxa were recorded, no broad effect of habitat (sites) on species diversity was observable. However, at Location 2, abundances were significantly higher at Site 3 (Forest) compared to Site 2 (Forest-fringe). The reasons were uncertain, but may be attributed to higher retention of allochthonous organic materials, trapped by in-stream cover and larger substrates. Investigations of adult stages by sticky traps supported benthic results recording community compositions and abundances dominated by Trichoptera and Diptera. Plecoptera were poorly represented. Location 2 recorded higher abundances of taxa, particularly Ephemeroptera and Plecoptera. Investigations of adult stages by light traps however did not produce any statistically significant differences in abundances between sites, between locations, or between sites across locations, and it is believed to be due to limited sampling replication combined with some biases of light trapping. This study indicates that the aquatic invertebrate community at Matapouri is diverse but also reasonably representative. Several rare or uncommon insects inhabit the catchment. It is therefore important that Iwi and the local Landcare Group, who invited and supported this research, together with the Department of Conservation, continue their efforts in protecting these areas. The resident fauna have the capacity to restock areas downstream, which are intended to be improved and restored through sediment control and riparian management.

A construção de Usinas Hidrelétricas (UHE) altera o regime hídrico natural do rio através da transformação de um ambiente lótico para lêntico (reservatório), podendo prejudicar o movimento dos peixes migradores. Portanto, o conhecimento dos movimentos e distribuição destes organismos em reservatórios é importante para o manejo de peixes migradores. Entretanto, não existem estudos que avaliem as diferenças sazonais nos deslocamentos e distribuição de peixes migradores neotropicais em pequenos reservatórios. Este estudo objetivou caracterizar os padrões de deslocamento e distribuição, bem como a relação com as variáveis ambientais e biométricas de Salminus brasiliensis usando a biotelemetria. O estudo foi desenvolvido entre janeiro e dezembro de 2012, na barragem Monjolinho (UHE Monjolinho), rio Passo Fundo (tributário do alto rio Uruguai, Brasil). Os indivíduos foram capturados, marcados a jusante e soltos a 900 metros a montante do eixo da barragem. Os dados foram coletados mensalmente através de rastreamentos móveis realizados de barco. Estações fixas (uma a jusante e outra a montante do reservatório) detectavam os sinais dos peixes marcados com os transmissores individualmente codificados. Mais da metade dos peixes (N = 15) conseguiram se deslocar para montante do reservatório. Dois indivíduos realizaram movimento descendente, 10 meses pós-soltura. Um indivíduo apresentou velocidade máxima de 2,4 km/h. Os maiores deslocamentos foram na época da atividade reprodutiva, entretanto os deslocamentos não mostraram um padrão claramente sazonal. A distribuição e área de vida apresentaram um padrão sazonal: no verão e primavera os indivíduos localizavam-se em ambientes distantes da barragem, no outono e inverno os indivíduos localizavam-se em trechos mais próximos da barragem. Os deslocamentos e a área de vida linear apresentaram forte relação com a vazão e precipitação. A distribuição foi influenciada pela temperatura, vazão, precipitação e nível de água. O monitoramento pela biotelemetria para espécies migradoras ameaçadas pela construção de hidrelétricas pode ser considerado em futuros esforços de conservação, como, por exemplo, nas indicações de áreas prioritárias para a fiscalização intensiva da pesca dos peixes migradores de alto valor comercial em reservatórios neotropicais. / The construction of hydropower plants (UHE) alters the natural flow dynamics of rivers by transforming them from lontic to lentic environments (reservoirs), and by hampering the movement of migratory fishes. Therefore, knowing the movements and distribution of organisms in reservoirs is important for the management of migratory fish species. However, there are no studies evaluating differences in seasonal movements and distribution of neotropical migratory fishes in small reservoirs. This study aimed to characterize the displacement and distribution patterns, and their relations with environmental variables of Salminus brasiliensis using biotelemetry. The study was conducted between January and December 2012, at Monjolinho Dam (UHE Monjolinho), in the Passo Fundo river (tributary of the upper Uruguay river). Individual fishes were captured and marked downstream from the Monjolinho dam and released 900 meters upstream of dam axis. Data were monthly collected by mobile tracking from a small boat. Fixed stations (one downstream the dam and other at upstream from the upper reservoir) detected signals from fish marked with individually encoded transmitters. More than half fishes (N = 15) were able to move upstream the reservoir. Two individuals were detected downstream the dam 10 months after released. One individual had maximum speed of 2.4 km /h (64.8 km/day). The largest displacements were in the period of reproductive activity, but movements did not show a clear seasonal pattern. Distribution in the reservoir and linear home range showed a seasonal pattern: in summer and spring individuals were located far from the dam, while in fall and winter they were located close to the dam. The displacement and linear home range showed a strong relationship with inflow and precipitation. The distribution was influenced by temperature, inflow, precipitation and water level. Biotelemetry monitoring of migratory species that are threatened by hydropower plants can be considered in future conservation efforts, for example, to assess priority areas for intensive monitoring of the fishing of migratory species.

Rehabilitation of sturgeon populations requires an understanding of sturgeon autecology during all life stages, especially during early life when high mortality occurs. To begin to understand sturgeon early-life history I determined river of origin on a multi-basin scale (i.e., potential rivers of origin). I then determined habitat needs and early life demographics on a more localized scale (i.e., specific river). Trace elements differ between river reaches of the central US and may be used to determine origin of age-0 sturgeon. My trace element analyses suggested that age-0 sturgeon captured in the Middle Mississippi River, which extends from the confluence of the Missouri River downstream to the confluence of the Ohio River, drifted from as far upstream as the Gavins Point Dam on the Missouri River (> 1200 km), while other individuals originated locally in the Middle Mississippi River. On a more refined scale of habitats, I used trawling to identify habitat features used. Age-0 Scaphirhynchus sturgeon catch rates were highest around artificial structures (i.e., wing dikes) and island areas while main channel habitat comprised the lowest catch rates. Within these habitats, young sturgeon frequently occupied low velocities (i.e., ~0.1), moderate depths (i.e., 2 to 5 m), and sand substrate. Although determination of river of origin and specific habitats used are imperative for restoration, sturgeon populations are likely regulated by factors within habitats that affect early-life dynamics. Mean sturgeon growth rates ranged from 1.42-1.50 mm/d over the four years but did not differ among years. Individuals hatched over a 25 to 50-d period and peak hatch dates were between 10- 20 May during all years. Hatching coincided with optimum spawning temperatures of 17-20oC and a rise in river stage. Abundance was positively related to river stage, with longer durations of high water related increasing abundance. Mortality of age-0 sturgeon increased with the number of days where water temperature exceeded 28 oC. In the end this study has set benchmarks for understanding factors affecting the early-life ecology of Scaphirhynchus sturgeon.

Os peixes podem migrar até milhares de quilômetros, buscando completar seu ciclo de vida. A migração de peixes presta importantes serviços aos ecossistemas aquáticos, como: dispersão de sementes, ciclagem de nutrientes e transferência de energia entre ambientes com alta produtividade e ambientes com baixa produtividade, exercendo assim papel fundamental nas redes tróficas de rios tropicais. Os ecossistemas aquáticos tropicais estão situados geralmente em países em desenvolvimento, que passam por rápida industrialização e aonde uma das principais fontes de energia elétrica vem da construção de usinas hidrelétricas, implicando no barramento e fragmentação do habitat de peixes migratórios. Por isso, os peixes migratórios estão sujeitos não somente aos impactos da pesca, mas também a degradação e a perda de conectividade entre os habitats utilizados. Países tropicais possuem pouco conhecimento ecológico sobre a migração de peixes, dificultando a aplicação de políticas de manejo e conservação. Por outro lado, pescadores artesanais possuem conhecimento detalhado sobre a ecologia dos peixes que pescam, sendo que esse conhecimento local pode servir como base para políticas de manejo pesqueiro e conservação. O objetivo deste trabalho é avaliar o conhecimento ecológico de pescadores sobre a migração de peixes ao longo de um rio tropical, o Rio Tapajós, um dos principais afluentes do Rio Amazonas, no Brasil. Ao todo, 273 pescadores foram entrevistados individualmente utilizando-se de questionários padronizados, ao longo de quatro trechos de rio: Baixo (entre Santarém e Belterra), Baixo-médio (entre Belterra e Aveiros), Médio (Itaituba) e Alto Tapajós (Jacareacanga). Neste estudo são analisadas e discutidas algumas hipóteses sobre a migração e movimentação de quatro espécies de peixes reconhecidamente migratórios: Filhote ou Piraíba (Brachyplatystoma filamentosum) Mapará (Hypophthalmus marginatus), Jaraqui (Semaprochilodus spp.) e Matrinxã (Brycon spp.), além de três peixes não considerados como sendo migratórios: Tucunaré (Cichla spp.), Pescada (Plagioscium squamosissimus) e Caratinga (Geophagus surinamensis). Segundo a maioria dos pescadores entrevistados, o Filhote migra rio acima e apresenta tamanhos maiores em trechos superiores (médio e alto) do rio, uma evidência de que a espécie utiliza estes habitats rio acima para desova. O Jaraqui e a Matrinxã apresentam padrões similares segundo os pescadores: migração longitudinal seguida de migração lateral. Entretanto, os pescadores mencionaram que Jaraqui, o peixe mais capturado em todos os trechos do rio dentre os peixes estudados, realiza migração a jusante durante a seca nos trechos Baixo e Baixo-médio Tapajós, indicando que a espécie retorna ao Rio Amazonas, provavelmente para desovar, diferentemente dos trechos Médio e Alto Tapajós onde não é citada migração a jusante, levantando a hipótese de que sejam populações com padrões migratórios distintos. O Mapará não foi citado no trecho superior do rio (Alto) e a migração lateral foi o principal movimento indicado pelos pescadores nos demais trechos ao longo do rio. Os resultados deste estudo têm implicações importantes para a conservação dos peixes. A construção de barragens vi nos trechos superiores do Rio Tapajós representa uma ameaça aos peixes migradores estudados, como o Filhote, o Jaraqui e a Matrinxã. Portanto é fundamental que estas informações sejam consideradas no planejamento energético e desenvolvimento da Amazônia. Recomenda-se investigar mais sobre a migração dos peixes no Rio Tapajós, para se discutir futuras estratégias de manejo e conversação. / Fish can migrate up to thousands of kilometers, seeking to complete their life cycle. The migration of fish provides important services to aquatic ecosystems, such as seed dispersal, nutrient cycling and energy transfer between high-productivity environments and low-productivity environments, thus playing a key role in the food webs of tropical rivers. Tropical aquatic ecosystems are often located in developing countries that undergo rapid industrialization and where a major source of electricity comes from the construction of hydroelectric power plants, which results in the impounding and fragmentation of habitat for migratory fish. Therefore, migratory fish are subject not only to the impacts of fishing, but also to the degradation and loss of connectivity between the habitats used. Tropical countries have little ecological knowledge about fish migration, hampering the implementation of management and conservation policies. On the other hand, artisanal fishermen have detailed knowledge about the ecology of fishes they catch, and such local knowledge can be used as the basis for fisheries management and conservation policies. The objective of this study is to assess the ecological knowledge of fishermen on fish migration along a tropical river, the Tapajós River, a major affluent of the Amazon River, in Brazil. Altogether, 273 fishermen were interviewed individually using a structured questionnaire along four stretches of the river: Low (between Santarém and Belterra), Low-medium (between Belterra and Aveiros), Medium (Itaituba) and Upper Tapajós (Jacareacanga). This study analyzed and discussed some hypotheses about the migration and movement of four known species of migratory fish: Filhote or Piraíba (Brachyplatystoma filamentosum), Mapará (Hypophthalmus marginatus), Jaraqui (Semaprochilodus spp.) and Matrinxã (Brycon spp.), as well as three species of fish considered as non-migratory: Tucunaré (Cichla spp.), Pescada (Plagioscium squamosissimus) and Caratinga (Geophagus surinamensis). According to most fishermen, Filhote migrates upstream and features larger sizes in the upper parts of the river (Medium and Upper Tapajós), an evidence that the species use these habitats upstream for spawning. The Jaraqui and Matrinxã have similar patterns according to the fishermen: longitudinal migration followed by vii lateral migration. However, the fishermen mentioned that Jaraqui, which is the fish most commonly caught among the fish studied along the river stretches, performs downstream migration during the draughts in Low and Low-Medium Tapajós, indicating that the species returns to the Amazon River, presumably to spawn, differently from the Medium and Upper Tapajós stretches, where downstream migration is not mentioned, raising the possibility that these are populations with distinct migration patterns. The Mapará was not mentioned in the upper part of the river (Upper) and the lateral migration was the main movement indicated by fishermen in the other stretches along the river. The results of this study have important implications for the fish conservation. The construction of dams in the upper parts of the Tapajós River is a threat to the migratory fish studied, such as the Filhote, the Jaraqui and the Matrinxã. Therefore, it is essential that the aforementioned information be considered in energy planning and development of the Amazon. It is recommended to further investigate the migration of fish in the Tapajós River in order to discuss future management and conversation strategies.

Mink (Mustela vison) are an important species because they occur at a high trophic level, they are considered a potential indicator species for environmental contaminants, and they are a popular target species among fur trappers. Despite the importance of mink, their ecology in North America is not well understood. I sampled 59 of 60 Hudson River tributaries with 2 scent stations randomly established along each tributary for 2 10-day monitoring periods to evaluate presence/absence of mink via remote camera photographs and tracks. When sampling was completed, I quantified microhabitat characteristics at 84 randomly selected scent stations. Statistical tests for microhabitat did not indicate a difference among variables selected for analysis between scent stations where mink visits were detected and those where mink visits were not detected. I also analyzed all scent stations for macrohabitat characteristics related to human disturbance, using 150 m circular buffers in ArcGIS 9.2. Although the percent cover of human disturbance was 7.0% greater at scent stations where mink were not detected, the difference was not significant and may therefore indicate that mink may have a tolerance for moderate human disturbances. I also evaluated the performances of 2 types of remote cameras (Moultrie Game Cameras: MGC I–40 and MGC 200) in detecting mink visits at scent stations as well as comparing remote camera detections of mink visits with observations of tracks. The MGC I–40 cameras detected a significantly greater number of mink visits (n = 50) compared to the MGC 200 cameras (n = 3). Detection of mink at scent stations was also significantly greater using the remote cameras compared with observations of mink tracks. Mink were also live–trapped and implanted with subcutaneous radiotransmitters. There were 13 mink captures (0.31 mink/100 trap–nights) with radiotransmitters being implanted in 12 (11 males and 1 female) mink. Overall 166 den sites were located with a mean of 15.9 den sites/mink. Microhabitat analysis of 33 used den sites and 33 unused potentially available den sites (UPADs) indicated that shoreline cover was significantly greater at used den sites. Macrohabitat analysis using 150 m circular buffers surrounding 76 used den sites and 76 unused potentially available sites (UPASs) indicated that human disturbance was 3.3% greater at the UPASs than at used den sites, but this difference was not significant. This may further suggest that mink may have a tolerance for moderate human disturbances. Den site structures most often used by mink included brushpiles or logjams (21.1%) and bank burrows (17.5%). The use of den site structures appeared to be largely based on shoreline cover and availability. The mean linear home range of male mink was 6.6 km (SE = 0.6, range 3.2 – 8.4 km), which was similar to the female's home range of 6.5 km. Ten mink home ranges encompassed portions of both the Hudson River and its tributaries accounting for a mean of 2.8 and 4.4 km, respectively. Mean daily movement distances of mink along shorelines was 659 m (SE = 42, range 0 – 3,087 m) and was significantly greater along tributaries than along the Hudson River.

A construção de Usinas Hidrelétricas (UHE) altera o regime hídrico natural do rio através da transformação de um ambiente lótico para lêntico (reservatório), podendo prejudicar o movimento dos peixes migradores. Portanto, o conhecimento dos movimentos e distribuição destes organismos em reservatórios é importante para o manejo de peixes migradores. Entretanto, não existem estudos que avaliem as diferenças sazonais nos deslocamentos e distribuição de peixes migradores neotropicais em pequenos reservatórios. Este estudo objetivou caracterizar os padrões de deslocamento e distribuição, bem como a relação com as variáveis ambientais e biométricas de Salminus brasiliensis usando a biotelemetria. O estudo foi desenvolvido entre janeiro e dezembro de 2012, na barragem Monjolinho (UHE Monjolinho), rio Passo Fundo (tributário do alto rio Uruguai, Brasil). Os indivíduos foram capturados, marcados a jusante e soltos a 900 metros a montante do eixo da barragem. Os dados foram coletados mensalmente através de rastreamentos móveis realizados de barco. Estações fixas (uma a jusante e outra a montante do reservatório) detectavam os sinais dos peixes marcados com os transmissores individualmente codificados. Mais da metade dos peixes (N = 15) conseguiram se deslocar para montante do reservatório. Dois indivíduos realizaram movimento descendente, 10 meses pós-soltura. Um indivíduo apresentou velocidade máxima de 2,4 km/h. Os maiores deslocamentos foram na época da atividade reprodutiva, entretanto os deslocamentos não mostraram um padrão claramente sazonal. A distribuição e área de vida apresentaram um padrão sazonal: no verão e primavera os indivíduos localizavam-se em ambientes distantes da barragem, no outono e inverno os indivíduos localizavam-se em trechos mais próximos da barragem. Os deslocamentos e a área de vida linear apresentaram forte relação com a vazão e precipitação. A distribuição foi influenciada pela temperatura, vazão, precipitação e nível de água. O monitoramento pela biotelemetria para espécies migradoras ameaçadas pela construção de hidrelétricas pode ser considerado em futuros esforços de conservação, como, por exemplo, nas indicações de áreas prioritárias para a fiscalização intensiva da pesca dos peixes migradores de alto valor comercial em reservatórios neotropicais. / The construction of hydropower plants (UHE) alters the natural flow dynamics of rivers by transforming them from lontic to lentic environments (reservoirs), and by hampering the movement of migratory fishes. Therefore, knowing the movements and distribution of organisms in reservoirs is important for the management of migratory fish species. However, there are no studies evaluating differences in seasonal movements and distribution of neotropical migratory fishes in small reservoirs. This study aimed to characterize the displacement and distribution patterns, and their relations with environmental variables of Salminus brasiliensis using biotelemetry. The study was conducted between January and December 2012, at Monjolinho Dam (UHE Monjolinho), in the Passo Fundo river (tributary of the upper Uruguay river). Individual fishes were captured and marked downstream from the Monjolinho dam and released 900 meters upstream of dam axis. Data were monthly collected by mobile tracking from a small boat. Fixed stations (one downstream the dam and other at upstream from the upper reservoir) detected signals from fish marked with individually encoded transmitters. More than half fishes (N = 15) were able to move upstream the reservoir. Two individuals were detected downstream the dam 10 months after released. One individual had maximum speed of 2.4 km /h (64.8 km/day). The largest displacements were in the period of reproductive activity, but movements did not show a clear seasonal pattern. Distribution in the reservoir and linear home range showed a seasonal pattern: in summer and spring individuals were located far from the dam, while in fall and winter they were located close to the dam. The displacement and linear home range showed a strong relationship with inflow and precipitation. The distribution was influenced by temperature, inflow, precipitation and water level. Biotelemetry monitoring of migratory species that are threatened by hydropower plants can be considered in future conservation efforts, for example, to assess priority areas for intensive monitoring of the fishing of migratory species.