ABSTRACT
Abstract Introduction: The Wood Thrush is a migratory bird that has experienced dramatic declines in its populations in recent decades. This species overwinters in forest fragments with intermediate levels of habitat modification in Central America. However, more studies detailing the use of remnant forests through time are needed to elucidate the threats this species faces in the wintering grounds. Objective: To understand the effects of environmental and forest structure variables on the occupancy of Wood Thrush in Northern Costa Rica. Methods: The study area was the Área de Conservación Guanacaste (ACG), located in Northern Costa Rica, in December 2016, and during the 2018-2019 migration season. We estimated Wood Thrush occupancy and detection probability in four locations of ACG (dry forest, cloud forest, and two locations in the wet forest) using single-season occupancy models. We also estimated Wood Thrush occupancy and probability of persistence in different months in three vegetation types (open area, secondary forest, and old-growth forest) in the wet forest of ACG using a multi-season occupancy model approach. Results: Wood Thrush occupancy was best described by precipitation in the four locations of the ACG; the probability of occupancy increased with precipitation. The average occupancy of Wood Thrushes varied with vegetation type: open area with shrubs and forest edge (0.69 ± 0.09), secondary forest (0.46 ± 0.1), and old-growth forest (0.61 ± 0.1). Wood Thrush probability of persistence responded partially to changes in precipitation, with an unexpected increase in persistence when the rainfall continued decreasing in the season. Conclusion: Wood Thrush occupancy was best predicted by changes in precipitation considering a larger spatial scale. Its probability of persistence partially varied with precipitation. An increase in persistence closer to Spring migration might be explained by the start of the breeding season of resident birds, potentially reducing territorial conflicts and conserving energy before migration. The long-term protection of wet forests in Northern Costa Rica is of paramount importance for the conservation of Wood Thrushes in their wintering grounds.
Resumen Introducción: El Zorzal del Bosque es un ave migratoria que ha experimentado caídas dramáticas en sus poblaciones en las últimas décadas. Esta especie pasa el invierno en fragmentos de bosque con niveles intermedios de modificación de hábitat en Centroamérica. Sin embargo, se necesitan más estudios que detallen el uso de los bosques remanentes a lo largo del tiempo para dilucidar las amenazas que enfrenta esta especie en las zonas de invernada. Objetivo: Comprender los efectos de variables ambientales y de estructura del bosque en la ocurrencia del Zorzal del Bosque en el Norte de Costa Rica. Métodos: El área de estudio fue el Área de Conservación Guanacaste (ACG), ubicada en el Norte de Costa Rica, en diciembre de 2016, y en la temporada migratoria 2018-2019. Estimamos la ocurrencia y la probabilidad de detección del Zorzal del Bosque en cuatro ubicaciones de ACG (bosque seco, bosque nuboso y dos ubicaciones en el bosque húmedo) utilizando modelos de ocurrencia de una sola temporada. También estimamos la ocurrencia del Zorzal del Bosque y la probabilidad de persistencia en diferentes meses en tres tipos de vegetación (área abierta, bosque secundario y bosque primario) en el bosque húmedo de ACG utilizando un enfoque de modelo de ocurrencia multi-estacional. Resultados: La ocurrencia del Zorzal del Bosque estuvo mejor descrita por la precipitación en las cuatro localidades del ACG; la probabilidad de ocurrencia aumentó con las precipitaciones. La ocurrencia media de zorzales varió con el tipo de vegetación: área abierta con arbustos y borde de bosque (0.69 ± 0.09), bosque secundario (0.46 ± 0.1) y bosque primario (0.61 ± 0.1). La probabilidad de persistencia del zorzal respondió parcialmente a cambios en la precipitación, con un aumento inesperado en la persistencia cuando las precipitaciones continuaron disminuyendo en la temporada. Conclusión: La ocurrecia del Zorzal del Bosque varió con la precipitación considerando una escala espacial mayor. Su probabilidad de persistencia varió parcialmente con la precipitación. Un aumento en la persistencia más cerca de la migración de primavera podría explicarse por el inicio de la temporada de reproducción de las aves residentes, lo que podría reducir los conflictos territoriales y conservar energía antes de la migración. La protección a largo plazo de los bosques húmedos en el norte de Costa Rica es de suma importancia para la conservación de los Zorzales del Bosque en sus zonas de invernada.
Subject(s)
Animals , Animal Migration , Passeriformes , Seasons , Costa RicaABSTRACT
Resumen Introducción: El humedal costero Poza de La Arenilla (HCPA), Callao, Perú, es un hábitat importante para el descanso y reposo de aves acuáticas, entre ellas la familia Laridae. Sin embargo, el humedal está sufriendo una degradación crítica debido al desarrollo de actividades antropogénicas. Objetivo: Evaluar la distribución espacio-temporal de las aves acuáticas de la familia Laridae reportadas en HCPA según la temporada del año entre 2013 y 2018. Métodos: Se realizaron muestreos quincenales en 11 zonas delimitadas de HCPA de enero 2013 a diciembre 2018, durante la mañana y la tarde, mediante el método de recuento total. Resultados: Se registraron 12 especies de la familia Laridae. Leucophaeus pipixcan fue la especie de mayor dominancia en la mayoría de las zonas estudiadas y su presencia se destaca en verano y primavera. Las especies con mayor distribución en el humedal son L. pipixcan, Larus dominicanus y Larus belcheri, que se registraron en todas las zonas estudiadas. La mayor abundancia total promedio de especies se registró en verano y la menor en invierno. Se observó un aumento gradual de la abundancia promedio de aves, siendo estos aumentos notables entre primavera y verano de un año a otro. Además, se observó una disminución de la riqueza global de los láridos durante el periodo evaluado. Se observó un patrón de variación estacional del índice de diversidad de Shannon-Weaver (H') similar de un año a otro, debido a que los láridos son aves migratorias, y una tendencia a la disminución del índice con el paso del tiempo. Conclusiones: El HCPA desempeña un papel fundamental para la avifauna acuática de la región. Se ha registrado la presencia de cinco especies migratorias y siete residentes de esta familia, las cuales muestran preferencias espaciales en diferentes zonas del humedal. A pesar de que se observa una disminución en la riqueza global de las especies en el tiempo, la abundancia promedio de aves aumenta.
Abstract Introduction: The coastal wetland Poza de La Arenilla (HCPA), located in Callao (Peru), is an important resting and roosting habitat for aquatic birds, including the family Laridae. However, the wetland is suffering critical degradation due to the development of anthropogenic activities. Objective: To evaluate the spatiotemporal distribution of aquatic birds of the family Laridae reported at HCPA seasonally during the period 2013-2018. Methods: Biweekly sampling was carried out in 11 delimited zones in HCPA between January 2013 and December 2018, during morning and afternoon hours using the total count method. Results: A total of 12 species of Laridae birds were recorded. Leucophaeus pipixcan is the most dominant species in most of the studied zones and its presence is highlighted in summer and spring. The species with the greatest distribution in the wetland was L. pipixcan, Larus dominicanus, and Larus belcheri, which were reported in all the zones studied. The highest average total abundance of species was recorded in summer, while the lowest in winter. A gradual increase in the average abundance of aquatic birds was observed, with these increases being noticeable between the springs and summers from one year to the following. Also, overall richness of the larids was observed to decrease throughout the period evaluated. A similar seasonal variation pattern of the Shannon diversity index (H') was observed from one year to the following, due the fact that Laridae are migratory, and a tendency for the index to decrease with the passage of time. Conclusions: The HCPA plays a key role for the aquatic birds of the region. The presence of five migratory and seven resident species of Laridae has been recorded, which show spatial preferences in different areas of the wetland. Despite a decrease in overall species richness over time, the average abundance of Laridae birds is increasing.
Subject(s)
Animals , Animal Migration/classification , Charadriiformes/classification , Wetlands , PeruABSTRACT
Abstract Estuaries are used by waterbirds as foraging, resting and nesting sites, serving also as shelter for migratory birds. The dynamics of this avifauna in an aquatic environment may be associated with the differences of time of day, tide height, temperature, wind speed and use of the site by different species. This study had the objective of evaluating behavioral aspects of aquatic birds, relating the influence of environmental variables with their activities. Bird counts were performed at the mouth of two important rivers of the state of Santa Catarina, Brazil, during two-hour intervals throughout the day in monthly samplings between June (2015) and May (2016). A total of 44 species were recorded, ten of which were migratory. The most recorded behaviors were foraging and resting. The Kruskal-Wallis analysis indicated no significant difference in behavior between the sampling intervals. The Bray-Curtis similarity test resulted in three groups: 1) - species that foraged most of the time; 2) - species that rested most of the time; and 3) - same time in both activities. The Indicator Species Analysis showed that 17 species were associated with only one microhabitat and 15 species with more than one. The Canonical Correlation Analysis indicated that only tide height, temperature and rainfall variables were correlated with the behaviors performed and only the resting activity was positively correlated with all variables. This may be associated with thermoregulation and the ability of some species to stay in midlitoral at high tide. The results demonstrate that different waterbird species used the studied areas in different ways. Thus, the heterogeneity of microhabitats in an aquatic environment of extreme importance for the coexistence and maintenance of the diversity of waterbirds.
Resumo Estuários são utilizados por aves aquáticas como locais de forrageio, descanso e nidificação, servindo, também, como pontos de parada para aves migratórias. A dinâmica dessa avifauna em um ambiente pode estar associada a diferenças entre horários do dia, altura da maré, temperatura, velocidade do vento e uso do local. Esse trabalho teve o objetivo de avaliar aspectos comportamentais de aves aquáticas, relacionando a influência de variáveis ambientais com suas atividades. Amostragens mensais foram realizadas na foz de dois importantes rios do Estado de Santa Catarina, Brasil, entre junho de 2015 e maio de 2016, em intervalos de duas horas no decorrer do dia. Um total de 44 espécies foram registradas, dez das quais foram migratórias. Os comportamentos mais observados foram forrageio e descanso. A análise de Kruskall-Wallis não indicou diferenças significativas no comportamento entre os horários de amostragem. O teste de similaridade Bray-Curtis resultou em três agrupamentos: 1) - espécies que forragearam na maior parte do tempo; 2) - espécies que descansaram na maior parte do tempo; e 3) - mesma quantidade de tempo em ambas atividades. A Análise de Espécies Indicadoras mostrou que 17 espécies estiveram associadas com apenas um microhabitat e 15 espécies com mais de um. A Análise de Correlação Canônica indicou que apenas as variáveis maré, temperatura e precipitação foram significativamente correlacionadas com os comportamentos demonstrados e apenas a atividade de descanso foi positivamente correlacionada com as todas as variáveis. Isso pode estar associado com a termorregulação e com a habilidade de algumas espécies de permanecer no mediolitoral durante a maré cheia. Os resultados demonstram que diferentes espécies de aves aquáticas utilizaram as áreas estudadas de diferentes maneiras. Assim, a heterogeneidade de microhabitats em um ambiente aquático é de extrema importância para a coexistência e a manutenção da diversidade de aves.
Subject(s)
Animals , Birds , Rivers , Brazil , EstuariesABSTRACT
ABSTRACT: Wild animals are hosts and reservoirs to many infectious agents, often unknown to the Scientific Community, which leads to serious health implications for natural and domestic environments. We conducted this research with the objective of diagnosing the occurrence of parasites of medical and veterinary interest in "coleirinhos" captured in the eastern region of the state of Acre, Brazil. We captured the specimens in August and September of 2017 using ornithological nets at the margins of Caeté river. We visually inspected the birds to evaluate the ectoparasites. Subsequently, we collected blood through a brachial vein puncture and rested the individuals in a cloth bag for 30 minutes to collect feces, after which we released them. Results of the visual inspection to detect and identify the ectoparasites were negative. Blood samples revealed the protozoan Haemoproteus sp., and the feces revealed cysts of Entamoeba histolytica and E. coli, oocysts of coccidia and eggs of Davaineidae. Coccidia was the most prevalent (69.2%) and abundant (34.15%) parasite reported. Parasites diagnosed in this study can promote the emergence of secondary infections in S. caerulescens individuals or other animals that are contaminated with these etiological agents, since, when migrating through different biomes of South America, other animal species can come into contact with these agents.
RESUMO: Os animais silvestres são hospedeiros e reservatórios de vários agentes infecciosos, muitas vezes desconhecidos para a comunidade científica, o que leva a sérias implicações na saúde dos ambientes naturais e domésticos. Esta pesquisa teve como objetivo diagnosticar a ocorrência de parasitos de interesse médico e veterinário em "coleirinhos" capturados no leste do Estado do Acre, Brasil. Os espécimes foram capturados nos meses de agosto e setembro de 2017 em redes ornitológicas as margens do Rio Caeté. Para a pesquisa de ectoparasitos, as aves foram inspecionadas visualmente. Após a inspeção, o sangue foi coletado por meio de punção da veia braquial e para coletas das fezes os indivíduos foram postos em descanso em saco de pano por 30min e depois foram soltos na natureza. As fezes, quando presentes, foram coletadas e acondicionadas em recipientes de plástico estéreis. A inspeção visual dos espécimes para detectar e identificar ectoparasitos resultou negativo. Nas amostras sanguíneas foi identificado o protozoário Haemoproteus sp.. Nas fezes foram encontrados os seguintes endoparasitos: cisto de Entamoeba histolytica e E. coli, oocisto de coccídeos e ovos de Davaineidae. Coccideos foram os endoparasitos mais prevalentes (69,2%) e os mais abundantes (34,15%). Os parasitos diagnosticados neste estudo podem propiciar o aparecimento de infecções secundárias nos indivíduos de S. caerulescens ou em outros animais que venham se contaminar com esses agentes etiológicos, pois com a migração dos mesmos, por diferentes biomas da América do Sul outras espécies de animais podem se infectar com esses agentes.
ABSTRACT
Abstract Estuaries are used by waterbirds as foraging, resting and nesting sites, serving also as shelter for migratory birds. The dynamics of this avifauna in an aquatic environment may be associated with the differences of time of day, tide height, temperature, wind speed and use of the site by different species. This study had the objective of evaluating behavioral aspects of aquatic birds, relating the influence of environmental variables with their activities. Bird counts were performed at the mouth of two important rivers of the state of Santa Catarina, Brazil, during two-hour intervals throughout the day in monthly samplings between June (2015) and May (2016). A total of 44 species were recorded, ten of which were migratory. The most recorded behaviors were foraging and resting. The Kruskal-Wallis analysis indicated no significant difference in behavior between the sampling intervals. The Bray-Curtis similarity test resulted in three groups: 1) - species that foraged most of the time; 2) - species that rested most of the time; and 3) - same time in both activities. The Indicator Species Analysis showed that 17 species were associated with only one microhabitat and 15 species with more than one. The Canonical Correlation Analysis indicated that only tide height, temperature and rainfall variables were correlated with the behaviors performed and only the resting activity was positively correlated with all variables. This may be associated with thermoregulation and the ability of some species to stay in midlitoral at high tide. The results demonstrate that different waterbird species used the studied areas in different ways. Thus, the heterogeneity of microhabitats in an aquatic environment of extreme importance for the coexistence and maintenance of the diversity of waterbirds.
Resumo Estuários são utilizados por aves aquáticas como locais de forrageio, descanso e nidificação, servindo, também, como pontos de parada para aves migratórias. A dinâmica dessa avifauna em um ambiente pode estar associada a diferenças entre horários do dia, altura da maré, temperatura, velocidade do vento e uso do local. Esse trabalho teve o objetivo de avaliar aspectos comportamentais de aves aquáticas, relacionando a influência de variáveis ambientais com suas atividades. Amostragens mensais foram realizadas na foz de dois importantes rios do Estado de Santa Catarina, Brasil, entre junho de 2015 e maio de 2016, em intervalos de duas horas no decorrer do dia. Um total de 44 espécies foram registradas, dez das quais foram migratórias. Os comportamentos mais observados foram forrageio e descanso. A análise de Kruskall-Wallis não indicou diferenças significativas no comportamento entre os horários de amostragem. O teste de similaridade Bray-Curtis resultou em três agrupamentos: 1) - espécies que forragearam na maior parte do tempo; 2) - espécies que descansaram na maior parte do tempo; e 3) - mesma quantidade de tempo em ambas atividades. A Análise de Espécies Indicadoras mostrou que 17 espécies estiveram associadas com apenas um microhabitat e 15 espécies com mais de um. A Análise de Correlação Canônica indicou que apenas as variáveis maré, temperatura e precipitação foram significativamente correlacionadas com os comportamentos demonstrados e apenas a atividade de descanso foi positivamente correlacionada com as todas as variáveis. Isso pode estar associado com a termorregulação e com a habilidade de algumas espécies de permanecer no mediolitoral durante a maré cheia. Os resultados demonstram que diferentes espécies de aves aquáticas utilizaram as áreas estudadas de diferentes maneiras. Assim, a heterogeneidade de microhabitats em um ambiente aquático é de extrema importância para a coexistência e a manutenção da diversidade de aves.
ABSTRACT
Haemosporidian parasites in the genus Plasmodium were recently detected through molecular screening in the Galapagos Penguin (Spheniscus mendiculus). We summarized results of an archipelago-wide screen of 3726 endemic birds representing 22 species for Plasmodium spp. through a combination of molecular and microscopy techniques. Three additional Plasmodium lineages were present in Galapagos. Lineage A-infected penguins, Yellow Warblers (Setophaga petechia aureola), and one Medium Ground Finch (Geospiza fortis) and was detected at multiple sites in multiple years [corrected]. The other 3 lineages were each detected at one site and at one time; apparently, they were transient infections of parasites not established on the archipelago. No gametocytes were found in blood smears of infected individuals; thus, endemic Galapagos birds may be dead-end hosts for these Plasmodium lineages. Determining when and how parasites and pathogens arrive in Galapagos is key to developing conservation strategies to prevent and mitigate the effects of introduced diseases. To assess the potential for Plasmodium parasites to arrive via migratory birds, we analyzed blood samples from 438 North American breeding Bobolinks (Dolichonyx oryzivorus), the only songbird that regularly migrates through Galapagos. Two of the ephemeral Plasmodium lineages (B and C) found in Galapagos birds matched parasite sequences from Bobolinks. Although this is not confirmation that Bobolinks are responsible for introducing these lineages, evidence points to higher potential arrival rates of avian pathogens than previously thought. Linajes Múltiples de Parásitos de Malaria Aviar (Plasmodium) en las Islas Galápagos y Evidencia de su Arribo por Medio de Aves Migratorias.
Subject(s)
Animal Migration , Birds/parasitology , Conservation of Natural Resources , Plasmodium/classification , Animals , DNA, Protozoan/chemistry , Ecuador , Introduced Species , Phylogeny , Plasmodium/genetics , Plasmodium/isolation & purificationABSTRACT
Resident and migratory shorebirds inhabit different kinds of wetlands such as lagoons, rivers and seashores among others. In recent years, these areas have been importantly affected by urban, agriculture and touristic activities, such as the Barra de Navidad lagoon, for which little information is available to support conservation programs. The aim of this work was to describe shorebirds temporal and spatial distribution in Barra de Navidad lagoon during three non-breeding seasons (1999-2000, 2006-2007 and 2008-2009). For this, monthly censuses were performed from November-April with the purpose of registering all the shorebirds species. We were able to identify 19 shorebirds species (three residents and 16 winter visitors), of which Charadrius wilsonia, Limosa fedoa and Tringa semipalmata were the most abundant. The greater number of species was registered for November, December and March of the first and third seasons. The greater number of individuals was registered when birds were feeding during low tides, mainly in December, January and February of the first and third seasons. At low tide, there was a great number of species and individuals in zone C. This area had muddy substrates that were exposed during low tides and were used to feed. Barra de Navidad lagoon provided suitable habitats for feeding and resting for resident and migratory birds. Twelve of the 19 species were considered as priority within the Mexican bird conservation strategy. However, these habitats are threatened by human activities performed in the nearby areas of the lagoon that may have negative consequences for the distribution, abundance and conservation of these species.
Hay un escaso conocimiento de las aves playeras en los humedales costeros de Jalisco, y en particular en la laguna Barra de Navidad. El presente trabajo contribuye al conocimiento de este grupo de aves y describe su distribución temporal y espacial en la laguna Barra de Navidad durante tres temporadas no reproductivas (1999-2000, 2006-2007 y 2008-2009). Se realizaron censos mensuales de noviembre-abril en las tres temporadas con el fin de registrar todas las especies de aves playeras. Se identificaron 19 especies (tres residentes y 16 visitantes de invierno), de las cuales Charadrius wilsonia, Limosa fedoa y Tringa semipalmata presentaron la mayor abundancia. Doce especies son consideradas como prioritarias en la “Estrategia para la Conservación y Manejo de las Aves Playeras y su Hábitat en México”. El mayor número de especies fue registrado en noviembre, diciembre y marzo en la primera y tercera temporada. El mayor número de individuos fue registrado alimentándose en marea baja, principalmente en diciembre, enero y febrero de la primera y tercera temporada. En marea baja hubo un mayor número de especies e individuos alimentándose en la zona C. Esta zona se caracterizó por tener sustratos lodosos expuestos durante marea baja y que fueron aprovechados por las aves para alimentarse. La laguna Barra de Navidad proporcionó hábitats de alimentación y descanso para las aves residentes y migratorias. Sin embargo, estos hábitats se ven amenazados por las actividades humanas realizadas dentro de la laguna, que sin duda tendrán consecuencias negativas para la distribución y abundancia de las aves playeras.
Subject(s)
Animals , Humans , Animal Migration/physiology , Birds/physiology , Ecosystem , Feeding Behavior/physiology , Birds/classification , Human Activities , Mexico , Population Density , Population Dynamics , Seasons , Space-Time ClusteringABSTRACT
El municipio Jesús Menéndez de la provincia Las Tunas, constituye un área biológica y ecológica de riesgo para la introducción del Virus del Nilo Occidental, por lo que se realizó un estudio descriptivo con el objetivo de identificar la presencia de aves migratorias, así como de sus lugares de asentamiento por ser áreas de riesgo; para ello se realizó una encuesta y un censo, obteniendo resultados positivos sobre el asentamiento de varias especies de aves migratorias procedentes de Norteamérica. Estos resultados permitieron realizar la estratificación de las áreas de introducción para el Virus del Nilo Occidental (AU)
Jesus Menéndez municipality in Las Tunas province constitutes a biological and ecological area of risk for the introduction of the West Nile Virus (WNO); that is why a descriptive study with the objective of identifying the existence of migratory birds as well as and their rest areas was done; a survey was applied and several species of migrant birds from North America showed positive. The results made possible the stratification of areas for the introduction of the West Nile Virus (AU)
Subject(s)
Animals , Birds , West Nile virus , Zoonoses , EpidemiologyABSTRACT
Distribution of aquatic birds in oxidation lagoons of La Paz city in South Baja California, Mexico. Taxonomic composition, spatial and temporal distribution of aquatic birds in oxidation lagoons (LO) of La Paz city in south Baja California, Mexico, were determined during 24 censuses realized in two-week intervals (April/98-March/99). There are five lagoons of 5 Ha each and 17 ha of terrains constantly flooded that serve as feeding areas for cattle and birds. One hundred twenty three species were observed, 75 of which were aquatic birds. A total of 46 041 observations were made (average 1 918 birds/census). Richness and abundance of aquatic birds were influenced mainly by migration of anatids and sandpipers. The first group had the greatest abundance due to its affinity towards fresh water bodies. The terrains were the favorite sites of dabbling ducks (Anas) and sandpipers. In contrast, two of the most abundant species (Oxyura jamaicensis, 12.5 % of all species, and Fulica americana, 8.8 %) restricted their presence to the oxidation lagoons. LO presented a bird structure of its own and atypical, according to the dryness of the region. Rev. Biol. Trop. 55 (2): 617-626. Epub 2007 June, 29.
Se determinó la composición taxonómica y la distribución espacial y temporal de aves acuáticas de las lagunas de oxidación (LO), de la ciudad de La Paz, Baja California Sur, México, durante 24 censos quincenales (abril/98marzo/99). Se trata de cinco lagunas, de cinco ha cada una y 17 ha de terrenos aledaños constantemente inundados que sirven como zona de alimentación para el ganado y las aves. Se observaron 123 especies de aves, de las cuales 75 fueron acuáticas. En total se realizaron 46 041 registros (promedio= 1 918 aves/censo). La riqueza y la abundancia estuvieron influenciadas por la migración, principalmente de anátidos y playeros, los primeros fueron el grupo más abundante, debido a su afinidad por cuerpos dulceacuícolas. Los terrenos aledaños fueron los preferidos por los patos vadeadores (Anas) y por los playeros. En contraste, dos de las especies más abundantes (Oxyura jamaicensis 12.5 % del total y Fulica americana 8.8 %), restringieron su presencia al espejo de agua. LO presentó un componente aviar propio y atípico, dada la aridez de la región.
