Abstract The Puna ibis Plegadis ridgwayi, is a species of Threskiornithidae that inhabits Andean wetlands and makes altitudinal migrations to the coast. Data from us, GBIF, bibliographic information and the Neotropical Waterbird Census (1992 to 2015) show that this species occurs in Ecuador, Peru, Bolivia, Argentina, and Chile, with a core area in Peru and Bolivia. It is most abundant in the latter two countries, with seven and three localities with more than 1% of the biogeographic population, respectively. They are found from 0 to 5000 m altitude (with peaks at 3000 to 4500 m and 0 to 500 m). The highest incidence of records is in southern and central Peru. There are high values of environmental availability in part of the high Andean zone from Ecuador to northern Chile and northwestern Argentina, as well as the coast of central and northern Peru. The expansion of the distribution towards the Peruvian north and coast may be due to environmental availability and the deterioration of its Andean habitat. In four coastal wetlands in central Peru, up to 818 ibises were recorded in 2006, the vast majority in Pantanos de Villa and Paraíso. The number of coastal migrants seems to be related to the intensity of droughts in the highlands of central Peru. The abundance of ibis in the high Andean Lake of Junín shows a historical decline, with emphasis after the 2004-2005 drought. This distributional expansion requires investigation of possible hybridisation with the other formerly allopatric species of the genus.

Resumen El ibis de la puna Plegadis ridgwayi, es una especie de Threskiornithidae que habita humedales andinos y realiza migraciones altitudinales hacia la costa. Datos propios, de GBIF, información bibliográfica y del Censo Neotropical de Aves Acuáticas (1992 a 2015) muestran que el ibis de la puna Plegadis ridgwayi se distribuye en Ecuador, Perú, Bolivia, Argentina y Chile, con las mayores densidades poblacionales en Perú y Bolivia en siete y tres localidades respectivamente, que acumulan más del 1% de la población biogeográfica. Se encuentran de 0 a 5000 m de altitud, con las mayores densidades entre 3000 a 4500 m y 0 a 500 m. La mayor incidencia de registros ocurre al sur y centro del Perú, así como costa del centro y norte del Perú. La ampliación de la distribución hacia el norte y costa peruana puede deberse a la disponibilidad ambiental y al deterioro de su hábitat andino. En cuatro humedales costeros del centro del Perú se registraron hasta 818 ibis en 2006, la gran mayoría en Pantanos de Villa y Paraíso. El número de migrantes costeros parece relacionado a la intensidad de sequías en la sierra del Perú central. La abundancia de ibis en el lago altoandino de Junín muestra una disminución histórica, con énfasis después de la sequía de 2004-2005. La expansión distribucional requiere investigar la posible hibridación con las otras especies del género antes alopátridas.

Abstract: We present a list of 253 bird species of the community of La Guásima (LG), a Priority Area for Conservation by Conanp since 2005, situated on the Pacific slope, in the municipality of Concordia, Sinaloa, based on exploratory field trips between 2003 and 2015 and the literature. Of these species, 110 (43.5%) are winter visitors, 58 present some type of endemism and 34 are in danger. Since the tropical dry forest constitutes the dominant vegetation in LG, it was decided to carry out monthly counts along 3 transects of variable length, from January 2009 to January 2010, to document the temporal distribution of richness and abundance, relative abundance and mean flock size of the birds associated with this kind of vegetation. A total of 141 species were observed in the forest. Species richness was highest during autumn and winter due to the presence of neotropical migrants while the 2 intertropical visitors, Myiodynastes luteiventris and Vireo flavoviridis had a noticeable influence on abundance from May to August. The latter and 7 other species were considered dominant. A total of 15 species were gregarious, forming flocks of between 5 and 17 individuals on average. Additional information is provided for accidental species and species at risk.

Resumen: Se elaboró una lista de 253 especies de aves que habitan en la comunidad de La Guásima (LG), Región Prioritaria para la Conservación por la Conanp desde 2005, ubicada en la vertiente del Pacífico, en el municipio de Concordia, Sinaloa, con base en recorridos exploratorios entre 2003 y 2015, así como en la literatura. De estas especies, 110 (43.5%) son visitantes de invierno, 58 presentan algún tipo de endemismo y 34 están en alguna categoría de riesgo. Debido a que la selva tropical seca constituye la vegetación dominante en LG, se decidió realizar conteos mensuales de todas las aves avistadas en 3 transectos de longitud variable de febrero de 2009 a enero de 2010, para documentar la variación temporal de riqueza y abundancia, abundancia relativa y tamaño promedio de parvada de las aves asociadas a dicha vegetación. Se avistaron 141 especies en total en la STS. Sobresale una riqueza alta durante otoño e invierno por la presencia de las migrantes neotropicales, mientras que las 2 visitantes intertropicales Myiodynastes luteiventris y Vireo flavoviridis tuvieron una influencia notoria en la abundancia de mayo a agosto. Esta última especie, junto con 7 especies más, constituyeron las especies dominantes. Un total de 15 especies fueron gregarias formando parvadas de entre 5 y 17 individuos en promedio. Se aporta información sobre algunas especies sobresalientes, tanto accidentales como en riesgo.

ResumenCuba tiene la mayor diversidad de avifauna del Caribe y un alto número de especies amenazadas, siendo el comercio ilegal una de las grandes amenazas. Esto es particularmente preocupante en las islas neotropicales porque las aves son capturadas para el mercado ilegal nacional e internacional. Se identificaron las especies de aves silvestres cautivas como mascotas en 10 localidades de ambientes urbanos y rurales de la región central de Cuba y se determinó la riqueza y abundancia entre agosto-noviembre 2014 y juniooctubre 2015. Se realizó un censo y un muestreo aleatorio en las áreas rurales y urbanas respectivamente. Al menos 24 especies y 973 individuos de seis órdenes y 11 familias estuvieron cautivos. El orden mejor representado fue: Passeriformes (13 especies), seguido de Accipitriformes (cuatro especies). Las familias mejor representadas fueron: Thraupidae (3.3 ± 0.33) y Cardinalidae (2.6 ± 0.45) y las localidades Patria (17), Morón (13) y Bolivia (13) de la zona urbana tuvieron la mayor riqueza. La riqueza de residentes (5.80 ± 0.68) fue mayor que la de endémicos (1.70 ± 0.30) y migratorios (2.70 ± 0.52). La riqueza de endémicos (2.5 ± 0.29) y residentes (7.75 ± 0.63) fue mayor en la zona urbana. Hubo más especies cautivas de Preocupación Menor (6.20 ± 1.02). En la zona rural predominó la categoría En Peligro (12.5 %). El 46 % de las especies se clasificaron con tendencia al decrecimiento, 33.3 % al aumento y 20.8 % a la estabilidad. Las especies más frecuentes fueron: Passerina cyanea, Melopyrrha nigra, Tiaris olivaceus y Passerina ciris. La abundancia de especies con tendencia al decrecimiento (63.4 ± 22.13) fue mayor a las que tienden a la estabilidad (14.8 ± 9.9). El tráfico existente conducirá a las extinciones de especies, fundamentalmente psitácidos y rapaces, y pone en riesgo varios servicios ecológicos. El comercio ilegal debe enfrentarse como un problema ambiental, económico y social. Se planteó una estrategia para controlar este comercio insostenible.

AbstractThe island of Cuba has the greatest diversity of birds in the Caribbean, and at the same time, a large number of endangered species. Illegal trade is one of major threats in Neotropical islands, because birds are captured for domestic and international illegal market. This study was undertaken with the aim to characterize the domestic market, in which captive wild birds are used as pets in the central region of Cuba. For this, a census and random survey to identify, and describe wild bird richness and abundance in 10 localities of urban and rural environments, was undertaken from August to November 2014, and from June to October 2015. Our results detected that at least 24 species and 973 individuals from six orders and 11 families were captive. The best represented order was Passeriformes (13 species), followed by Accipitriformes (four species). The best-represented families were Thraupidae (3.3 ± 0.33) and Cardinalidae (2.6 ± 0.45). Besides, the localities of Patria (17), Morón (13) and Bolivia (13) in the urban area had the highest richness. The richness of residents (5.80 ± 0.68) was higher than the endemics (1.70 ± 0.30) and migrants (2.70 ± 0.52), while the richness of endemics (2.5 ± 0.29) and residents (7.75 ± 0.63) was higher in urban areas. There were more captive species with Least Concern category (6.20 ± 1.02), but the Endangered category predominated in rural areas (12.5 %). The most common species were Passerina cyanea, Melopyrrha nigra, Tiaris olivaceus and Passerina ciris. A total of 46 % of the species were classified with a tendency to decrease, 33.3 % to increase and 20.8 % to stability. The abundance of species with a tendency to decrease (63.4 ± 22.13) was higher than those that tend to stability (14.8 ± 9.9). The actual traffic will lead to species extinction, mainly parrots and raptors, threatening several ecological services. Illegal trade should be addressed as an environmental, economic and social problem. Strategy for controlling this unsustainable trade was proposed. Rev. Biol. Trop. 65 (3): 962-974. Epub 2017 September 01.

Mechanical removal of shrublands is a recent management practice adopted in the semi-arid steppes of Magallanes. This involves partially removing the shrub cover in strips, in order to improve the access of sheep and facilitate the production of forage biomass. Although this procedure affects thousands of hectares, very little is known about the ecological effects that could determine changes in the vegetation and associated fauna. We studied the integrated effect of the motorized control of Romerillo (Chilliotrichum diffusum [G. Fort.] Kuntze) shrubland on composition, structure and functional diversity, by comparing different removal intensities: a) without shrub removal, b) intermediate removal, c) high removal of shrub coverage. We evaluated plant diversity by means of intercept-point transects, and bird abundance using point station census. The information was analyzed with univariate (Kruskal-Wallis), and multivariate procedures (e.g. MRPP, Indval, RLQ, Fourth-Corner), in order to correlate habitat structure with the composition and functional traits of bird assemblages. Bird abundance and species richness decreased significantly when shrub removal was high, but not in the case of intermediate removal. We found species-specific responses, associated with all treatments, and loss of bird assemblage identity, after shrub removal. Four species were detected as indicators of natural shrublands (Austral Canastero, Patagonian Sierra Finch, House Wren, Austral Thrush), while only one was associated with removal (Correndera Pipit). Insectivore birds, Neotropical migrants and foliage nesting birds were positively associated with Romerillo coverage, while omnivores, ground nesting, ground feeders and resident birds were associated with graminoids plants when shrubs were removed. Romerillo shrubs seem to provide a key structure for a positive association with the functional traits of specialist birds, in contrast with removed shrub sites, where abundance of other open land specialists were greater.

La remoción mecánica de matorrales, es una práctica agropecuaria reciente en la estepa semi-árida de Magallanes, que consiste en la remoción parcial de franjas de matorrales para mejorar el acceso del ganado e incrementar la producción de biomasa forrajera. Aunque esta práctica afecta miles de hectáreas, se sabe muy poco sobre los efectos ecológicos asociados que determinan cambios en la vegetación y la fauna dependiente. Investigamos el efecto integrado del control mecánico en la composición, estructura y diversidad funcional de aves del matorral dominado por Romerillo (Chilliotrichum diffusum [G. Fort.] Kuntze), mediante la comparación entre diferentes intensidades de remoción: a) sin remoción, b) remoción intermedia, c) remoción alta. Se evaluó la diversidad de plantas mediante puntos de intercepto, así como la abundancia de aves con parcelas de radio fijo. La información fue analizada mediante procedimientos univariados (Kruskal-Wallis) y multivariados (e.g. MRPP, Indval, RLQ, Fourth-Corner), para relacionar la estructura del hábitat con la composición, estructura y rasgos funcionales de los ensambles de aves. La abundancia y riqueza de aves disminuyeron significativamente cuando la remoción fue alta, no así con remoción intermedia. Se encontraron respuestas especie-específicas asociadas a los tratamientos, indicando pérdida de identidad del ensamble de aves en ambas situaciones con remoción. Cuatro especies de aves fueron detectadas como indicadoras del matorral sin remoción (Canastero del sur, Cometocino patagónico, Chercán, Zorzal), mientras que sólo una especie fue asociada a los matorrales removidos (Bailarín chico). Las aves insectívoras, migrantes Neotropicales y nidificantes de follaje estuvieron positivamente asociadas a la cobertura del Romerillo, mientras que los omnívoros, nidificantes del suelo, forrajeras del suelo y residentes se asociaron positivamente con la cobertura de graminoides, donde el Romerillo se removió. El matorral parece proporcionar estructuras claves para la asociación positiva con rasgos funcionales y especialistas dependientes de arbustos, a diferencia de los sitios con control mecánico, donde otros especialistas de ambientes abiertos, tienen mayores abundancias.

La región de la Sierra Madre Oriental (SMO) en el estado de San Luis Potosí en México es considerada un sitio de relevancia para la conservación de la avifauna a nivel nacional. Por lo anterior, el objetivo de este estudio fue analizar la distribución geográfica de las aves en la zona para identificar las áreas con mayor concentración de la riqueza y evaluar su estado actual de conservación para fundamentar la necesidad de incrementar la superficie dedicada a las áreas naturales protegidas en el futuro. Se recolectó información proveniente de diversas bases de datos de colecciones y museos, además de realizar trabajo de campo en el periodo de enero 2009 a Mayo 2011. Se modelaron las distribuciones potenciales para 284 especies con el programa GARP y se elaboró un mapa de consenso para determinar la ubicación espacial de las áreas con condiciones ambientales para soportar el mayor número de especies. Finalmente, se evaluó la representatividad de las zonas dedicadas a la conservación para las aves. Se registraron 357 especies, de las cuales el 71.4% son residentes permanentes, 19% son migratorias de invierno y 3.9% residentes de verano. Del total, 41 especies son endémicas y 48 se encuentran en alguna categoría de riesgo; la mayor concentración de especies se presentó en las coberturas de bosques de encino, bosques mesófilos y selvas medianas y bajas caducifolias, en un intervalo altitudinal entre 100-1 500m con una más alta cantidad de nichos en la parte centro y hacia el sur y este de la región. Sólo el 10% de las zonas con alto potencial de número de especies está incluido como área de importancia para la conservación de las aves y el 3% del total de áreas potenciales está bajo alguna categoría estatal de protección; sin embargo, ninguna de las áreas tiene un plan de manejo que esté siendo aplicado y monitoreado. La información generada es importante para el desarrollo de propuestas de conservación para las aves en la región.

The Sierra Madre Oriental region in the mexican state of San Luis Potosí is a relevant place for bird conservation at a country level. Therefore the main goal of this study was to analyze the geographic patterns of distribution and the conservation current state of the birds, to support the needs to expand the conservation areas in the future. Data was collected from various databases of zoological museums and collections, and field sampling methods conducted from January 2009 to May 2011. Potential distributions were modeled for 284 species using GARP software and then a map was developed to determine areas with favorable environmental characteristics for the distribution of species richness. Finally, the importance of conservation areas for the potential distribution of birds in the region was evaluated. A total of 359 species were recorded of which 71.4% are permanent residents, 19% are winter migrants and 4% are summer residents. From this total, 41 species were endemic, 47 were species at risk and 149 were neotropical migrants. The largest species richness correspond to oak forests, cloud forests, and tropical moist forests located at altitudes from 100m to 1 500m. Their potential distribution was concentrated towards the center and Southeast of the study area. Only 10% of areas with a high potential conservation was included in areas of priority for bird conservation (AICA) and just 3% of all potential areas were under some governmental category of protection. However, no conservation area has a management plan currently applied and monitored. The information generated is important for the development of management proposals for birds conservation in the region.

El papel de los paisajes rurales para la conservación de la biodiversidad adquiere cada vez más importancia debido a los cambios y reducción en los hábitats naturales. Es necesario, por tanto, caracterizar la biodiversidad en paisajes rurales e identificar herramientas que promuevan su conservación. Con el apoyo de la Iniciativa Darwin para la Preservación de las Especies, se caracterizó la avifauna presente en 80 fincas cafeteras en los municipios de Manizales y Palestina, Caldas. El muestreo de las aves se realizó por medio de recorridos libres dentro de cada finca. Para cada especie, se evaluó su abundancia, se determinó el gremio alimenticio y de hábitat al que pertenecían y se estimó su índice de vulnerabilidad. En los dos municipios, se observaron 100 especies de aves: 11 migratorias boreales y 89 residentes. En los dos municipios estuvieron presentes 68 especies, y 24 especies se registraron solamente en Palestina y 8 sólo en Manizales. La comunidad de aves incluyó una alta proporción de especies de zonas abiertas, pocas especies con abundancias altas y muchas con abundancias bajas, pocos especialistas, una gran mayoría de especies con vulnerabilidades bajas y una ausencia de especies de vulnerabilidades altas. Los resultados de este estudio pueden ser utilizados para identificar los elementos del paisaje rural que tienen mayor valor y donde deben enfocarse los esfuerzos de conservación.

The contribution of agricultural lands to biodiversity conservation has acquired special importance, due to transformations and reductions of natural habitats. There is a need to study biodiversity in agricultural areas in order to identify tools that promote biodiversity conservation. With the support of Darwin Initiative for the Preservation of Species, we characterized the avifauna in 80 coffee farms of Manizales and Palestina municipalities, in Caldas, Colombia. Birds were recorded during free walks along pathways in each farm. For each species, we determined its abundance, trophic and habitat guilds, and vulnerability index. We recorded a total of 100 species in both municipalities: 11 were Neotropical migrants and 89 were resident species. Sixty-eight species were present in both municipalities, whereas 24 were recorded only in Palestina and 8 were recorded only in Manizales. The bird community included a large proportion of species from open areas, a few species with high abundance and a large percentage were species with low abundance. In addition, we found very few specialized birds, and a great majority were species with low vulnerability index. Species with the highest vulnerability index were completely absent. The results of our study can be used to identify the habitats of the rural landscapes that have more value, and where the conservation efforts should be focused.

No hemisfério norte, o censo de aves é fundamental para gerar informações que auxiliam na compreensão de tendências populacionais. Tais censos, devido à marcada sazonalidade deste hemisfério, são realizados durante dois momentos distintos: na estação reprodutiva (aves residentes) e no inverno (quando as aves migratórias deixam determinadas regiões). Na região neotropical, porém, dependendo da localidade, as aves podem se reproduzir durante qualquer ou vários períodos do ano; podem ou não migrar, e aquelas que o fazem podem apresentar um padrão assincrônico. Em contraste com o hemisfério norte, tendências populacionais são desconhecidas, bem como o impacto das taxas rápidas de urbanização e desmatamento, que também são pouco monitoradas. Para melhor entender padrões temporais de riqueza e abundância de aves, e avaliar como um censo similar pode ser implementado na América tropical, foram utilizados pontos de escuta ao longo de 12 meses em uma localidade no Estado de São Paulo, sudeste do Brasil. Os censos ocorreram duas vezes por dia (manhãs/tardes) em uma floresta semidecidual ao longo de transecções com 10 pontos (20 pontos por dia) distantes 200 m entre si e com raio de detecção limitado em 100 m. Ambas as riquezas e abundâncias de aves foram maiores durante as manhãs, mas as curvas de acumulação sugerem que os censos vespertinos com maior esforço amostral podem fornecer resultados similares aos censos matutinos. Riqueza e abundância das aves não variam de acordo com estações (i.e., sem padrão aparente entre reprodução e migração), enquanto espécies exclusivas foram encontradas todos os meses e relativamente poucas espécies (20%) foram registradas em todos os meses do ano. Durante este ano, 84% de todas as aves florestais da área estudada foram registradas. Sugerimos que a metodologia de pontos de escuta pode ser utilizada à semelhança dos censos do hemisfério norte. Recomendamos ainda que o esforço amostral em transecções deva incluir ao menos 20 pontos, e que o início da contagem das aves deva ser sazonal, utilizando o período de migração das espécies austrais (e os seis meses seguintes) para coordenar pontos de escuta. Por último, sugerimos que os censos no Brasil e até mesmo na América Latina podem ajudar no entendimento de tendências populacionais, mas também demandam maior esforço do que o observado em latitudes temperadas, devido à maior riqueza de espécies e diferenças nas dinâmicas de reprodução e migração. Por meio do uso de censos de aves coordenados poderá ser desenvolvida uma técnica para os trópicos que irá gerar informações que permitam acompanhar tendências populacionais, com benefícios para a conservação das aves, similarmente aos censos realizados em países do hemisfério norte.

In the northern hemisphere, bird counts have been fundamental in gathering data to understand population trends. Due to the seasonality of the northern hemisphere, counts take place during two clearly defined moments in time: the breeding season (resident birds) and winter (after migration). Depending on location, Neotropical birds may breed at any time of year, may or may not migrate, and those patterns are not necessarily synchronous among species. Also in contrast to the northern hemisphere, population trends and the impact of rapid urbanization and deforestation are unknown and unmonitored. Throughout one year, we used point counts to better understand temporal patterns of bird species richness and relative abundance in the state of São Paulo, southeastern Brazil, to examine how to implement similar bird counts in tropical America. We counted birds twice each day on 10 point transects (20 points day‑1), separated by 200 m, with a 100 m limited detection radius in a semideciduous tropical forest. Both species richness and bird abundance were greater in the morning, but accumulation curves suggest that longer-duration afternoon counts would reach the same total species as in morning counts. Species richness and bird abundance did not vary seasonally and unique species were counted every month; relatively few species (20%) were present in all months. Most (84%) known forest species in the area were encountered. We suggest that point counts can work here as they do in the northern hemisphere. We recommend that transects include at least 20 points and that the simplest timing of bird counts would also be seasonal, using timing of migration of austral migrants (and six months later) to coordinate counts. We propose that bird counts in Brazil, and elsewhere in Latin America, would provide data to help understand population trends, but would require greater effort than in temperate latitudes due to greater species richness and different dynamics of reproduction and migration. With collaboration among ornithologists and coordinated bird surveys, we may develop a technique for the tropics that would yield information for population trends and conservation of birds, similar to counts in temperate latitudes.

A composição e abundância da ictiofauna da escada de peixes da barragem de Ourinhos, a mais nova hidrelétrica (fechada em 2005) na sequência de barragens construídas no rio Paranapanema, foram avaliadas três vezes em um ciclo diário, em três períodos de coleta, dois no verão e um no inverno de 2008-2009. A escada foi fechada e esvaziada e os peixes coletados e identificados, antes da devolução da maior parte deles a jusante. A ictiofauna da escada foi comparada à do reservatório de Ourinhos, coletada na mesma época. Vinte e sete espécies e 4862 indivíduos foram coletados na escada. Pimelodus maculatus foi a única espécie migradora coletada, mas em número baixo na escada, onde predominaram espécies sedentárias pequenas. As espécies mais abundantes foram as sedentárias Apareiodon affinis, Bryconamericus stramineus, Astyanax fasciatus e Parodon nasus. Observações feitas na janela da escada revelaram que os peixes realizavam movimentos ascendentes e descendentes. A escada de peixes é um microhabitat habitado por uma abundante associação de organismos bentônicos que é provavelmente usada como recurso alimentar pela ictiofauna na escada. A similaridade entre a ictiofauna no reservatório de Ourinhos e na escada é baixa (26%). A riqueza de espécies migradoras no trecho entre os reservatórios a montante (Chavantes) e a jusante (Salto Grande), antes do fechamento da barragem de Ourinhos (23 espécies) foi reduzida para 16 e 12 espécies, respectivamente em Salto Grande e Ourinhos, depois do fechamento da barragem, e a apenas uma espécie na escada

The composition and abundance of the fish assemblage were evaluated in the fish ladder of Ourinhos Dam, the newest dam (closed in 2005) in the cascade of dams constructed on the Paranapanema River. Samplings were carried out three times on a diel cycle, in three sampling periods, two in the warm season and one in the cold season of 2008 - 2009. The ladder was closed and emptied and the entire fish assemblage was sampled and identified. Most individuals were released alive downstream of the dam. The assemblage found in the ladder was compared with the fish fauna sampled in the reservoir and in downstream sites, in the same period. Twenty seven species and a total of 4682 individuals were caught in the ladder. Pimelodus maculatus was the only migratory species, which was caught in low number in the ladder (0.04% of the total captured), where small sedentary species predominated. The most abundant species were the non-migratory Apareiodon affinis, Bryconamericus stramineus, Astyanax fasciatus and Parodon nasus. Individuals observed in the ladder's window were moving up- and down the passage. The fish ladder is a microhabitat inhabited by an abundant association of benthic organisms that is probably used as a food resource for the fish assemblage in the ladder. The similarity between the fish fauna in the ladder and that of the Ourinhos Reservoir was low (26%). The species richness of migrants in the stretch between the uspstream reservoir (Chavantes) and the downstream one (Salto Grande), before the Ourinhos dam closure (23 species) was reduced to 16 and 12 species in Salto Grande and Ourinhos reservoirs, respectively, after the dam closure, and to a single species in the ladder.

Este artigo apresenta resultados da avaliação de passagem de peixes na escada localizada na Usina Hidrelétrica Engenheiro Sérgio Motta - CESP (rio Paraná, Porto Primavera, Brasil). A avaliação foi concebida para quantificar a entrada e proporções de passagem de quatro espécies de peixes migradores de longa distância: Brycon orbignyanus (piracanjuba), Piaractus mesopotamicus (pacu), Prochilodus lineatus (curimba) e Rhinelepis aspera (cascudo-preto). As proporções de encontrar e entrar na escada variaram de 7,4% (Prochilodus lineatus) para 55,4% (Piaractus mesopotamicus). A proporção de passagem através da escada variou de 31% (R. aspera) a 100% (Prochilodus lineatus). Os peixes que foram marcados e soltos no interior da escada apresentaram taxas maiores de falha do que aqueles que entraram voluntariamente. O tempo médio para passar variou de 1,48 horas (Prochilodus lineatus) para 178,9 horas (R. aspera). A taxa de falha foi maior no extremo inferior da passagem para peixes. Embora alguns indivíduos de todas as espécies passaram com sucesso, desafios significantes permanecem para restaurar a conectividade do alto rio Paraná.

This paper presents results of a fishway evaluation performed at the Engenheiro Sérgio Motta Hydroelectric Power Plant (known as Porto Primavera) - CESP, Paraná River, Brazil. The evaluation was designed to quantify entry and passage proportions of 4 long-distance migratory fish species: Brycon orbignyanus (piracanjuba), Piaractus mesopotamicus (pacu), Prochilodus lineatus (curimba), and Rhinelepis aspera (cascudo-preto). Proportions finding and entering the fishway differed between species, ranged from 7.4 % (Prochilodus lineatus) to 55.4% (Piaractus mesopotamicus). Also, proportion passing was different between species, ranged from 31% (R. aspera) to 100% (Prochilodus lineatus). Fish that were marked and released within the fishway had greater failure rates than those that entered volitionally. Total time to pass ranged from 1.48 hours (Prochilodus lineatus) to 178.9 hours (R. aspera). Failure rates were greatest in the lower end of the fishway. Although some individuals of all species passed successfully, significant challenges remain to restoring connectivity of the upper Paraná River.

Mais de 450 barragens foram construídas no alto rio Paraná, Brasil, nos últimos 40 anos. A regulação dos rios por barragens é considerada um dos fatores primários de redução da diversidade de peixes e depleção de espécies migratórias. Em contraste, somente duas grandes barragens foram construídas nos trechos mais inferiores da bacia do rio da Prata. No momento, há uma grande preocupação acerca do impacto dos represamentos sobre espécies que se constituem a base da pesca comercial e esportiva na bacia. Este artigo aborda o desempenho das passagens de peixes das barragens de Yacyreta e Salto Grande, monstrando que as mesmas falham na transferência de grandes quantidades de espécies migratórias para os trechos a montante. A barragem de Yacyreta tem dois elevadores com problemas importantes de projeto. Como resultado, a eficiência na passagem das espécies-alvo é menor do que 2%. A diversidade das espécies transferidas é baixa, uma vez que 85% dos espécimes dominantes nos elevadores foram representadas por uma espécie de Pimelodidae (Pimelodus maculatus) e duas de Doradidae (Oxydoras kneri e Rhinodoras dorbignyi). A passagem de grandes espécies alvo migratórias raramente compreende até 5% do número de peixes no sistema de passagem. A barragem de Salto Grande tem duas passagens do tipo eclusas de Borland linstaladas, cuja performance varia consideravelmente dependendo da operação da casa de força e dos vertedouros, bem como da elevação de nível no canal de fuga. A maioria dos espécimes que passam pertencem a uma pequena espécie de Pimelodidae (Parapimelodus valenciennis) e a uma espécie de Engraulidae (Lycengraulis grossidens). Um novo direcionamento no desenho de passagens de peixes é necessário para a preservação das espécies migratórias em rios Sul Americanos. Informações integradas de geomorfologia (habitat), atratores de natureza hidrodinâmica detectável pelos peixes para selecionar as rotas de migração ascendentes e descendentes, capacidade natatória dos peixes e estudos detalhados de populações são necessárias.

Over 450 dams have been constructed in the upper Paraná River basin in Brazil during the past 40 years. River regulation by these dams is considered a primary factor in the reduction of fish diversity and depletion of migratory species. In contrast to the upper Paraná Basin, only two large dams (both with upstream fish passage) have been constructed in the lower La Plata River basin. Fishery managers in the lower basin are concerned that existing and planned dams will further deplete populations of migratory fish species that constitute important recreational and commercial fisheries as has occurred in the upper basin. We assessed the sustainability of fisheries in the lower basin in the face of increased river regulation by using literature information to describe the efficiency of the fish passage systems used to mitigate river regulation impacts on fisheries. Our analysis shows that fish passage systems at both lower basin dams, Yacyreta and Salto Grande, fail to transfer sufficient numbers of upstream migrants to sustain populations of migratory species. Fish passage efficiency of target species in the fish elevators at Yacyreta is less than 2%. Fish diversity in the fish elevators is low because about 85% of the fish belong to only three non-migratory species (Pimelodus maculatus, Oxydoras kneri and Rhinodoras dorbignyi). Large migratory species targeted for passage rarely comprise even 5 % of the fish number in the passage system. The two Borland locks at Salto Grande Dam cannot dependably pass large numbers of migratory species because passage efficiency is dependent upon interactions of powerhouse and spillway operation with tailrace elevations. Most species in the Borland system were either a small catfish (Parapimelodus valenciennis) or a engraulid (Lycengraulis grossidens). Again, the targeted migratory species were not abundant in the passage system. We conclude that existing fish passage technology in the lower basin is inadequate and that improved fish passage designs are required to conserve migratory species. These designs must be based on integrated information from geomorphology (habitat), natural fish behavior, fish swimming capabilities, and detailed population studies.