Using Acoustic and Physiological Characteristics for Ecological Approaches of Birds in a Fragmented Landscape in Central Amazonia

In Amazon, the construction of hydroelectric dams is a growing factor in the biodiversity loss. In such environments, fragments acts as true islands, presenting low species richness on small islands. Consequently, tools that can monitor changes in communities are becoming increasingly important. In the first chapter, we evaluated the performance of seven acoustic indices (biodiversity indices based on the soundscapes analysis) in forest islands within an anthropogenic archipelago of central Amazonia, to address the following questions: (1) is there a relationship between bird richness and acoustic indices? (2) what is the relationship between soundscape patterns and landscape features such as island size? (3) how do soundscapes change throughout the day in islands of different sizes? and finally; (4) how do birds and cicadas use their acoustic space on islands of different sizes? In fragmented environments it is also necessary uncover the physiological mechanisms underlying the success of organisms living in disturbed habitats. In the second chapter, we use the corticosterone levels present in bird feathers as a measure of physiological stress, assessing whether corticosterone levels reflect the effects of landscape fragmentation related to the island size. For the first chapter, 12 islands and two areas of continuous forest were sampled. Using two autonomous recorders per area, one-minute recordings were made at five-minute intervals, for 24 hours, for three consecutive days. The acoustic indices exhibited different patterns, with marked changes between day and night. Our results show that five indices (acoustic complexity, acoustic diversity, acoustic entropy, median of the amplitude envelope and spectral flatness) reflect the species richness in each area. When we correlate the acoustic indices with island size, only the acoustic entropy index had significant results, presenting higher values with increasing area size. For the second chapter, we captured birds in 13 islands of varying size and in two continuous forests and analysed feather corticosterone levels of 265 individuals from eight different species. Our findings did not support the hypothesis that corticosterone varies in relation to island size, except for Hypocnemis cantator, which presented the predicted pattern: decreasing feather corticosterone levels with increasing island size. Overall, we conclude that even in a highly diverse environment, such as tropical forests, acoustic indices provide an excellent complementary tool for biodiversity assessment when provided with a ground-truthed database. Further studies are necessary to assess the reliability of corticosterone levels as a physiological measurement of stress and to determine which parameters are useful to understand how insularization caused by human activities may influence the resistance of avian populations to habitat disturbances.Na Amazônia, a construção de usinas hidrelétricas é uma ação que amplia a perda de biodiversidade. Nesses ambientes, fragmentos funcionam como ilhas verdadeiras, apresentando uma baixa riqueza de espécies em ilhas pequenas. Dessa maneira, ferramentas que possam monitorar mudanças nas comunidades estão se tornando cada vez mais importantes. No primeiro capítulo, avaliamos o desempenho de sete índices acústicos (índices de biodiversidade baseados na análise da paisagem acústica) em um ambiente fragmentado na Amazônia central, para acessar: (1) a relação entre riqueza de aves e índices acústicos; (2) os padrões da paisagem acústica associadas ao tamanho da ilha e (3) para caracterizar os padrões das paisagens acústicas nas ilhas ao longo de 24h. Em ambientes fragmentados também é necessário entender os mecanismos fisiológicos fundamentais ao sucesso dos organismos que vivem nesses ambientes. No segundo capítulo, usamos os níveis de corticosterona presentes nas penas das aves como uma medida dos indicadores fisiológicos de estresse, avaliando se os níveis de corticosterona refletem os efeitos da fragmentação do ambiente relacionados ao tamanho da ilha. No primeiro capítulo, foram amostradas 12 ilhas e duas áreas de floresta contínua. Utilizando dois gravadores autônomos por área, foram feitas gravações de um minuto com intervalos de cinco minutos, durante 24 horas, por três dias consecutivos. Os índices acústicos exibiram diferentes padrões, com mudanças marcantes entre dia e noite. Nossos resultados mostram que cinco índices (complexidade acústica, diversidade acústica, entropia acústica, mediana do envelope de amplitude e achatamento espectral) refletem a riqueza de espécies em cada área. Quando relacionamos os índices acústicos com o tamanho da ilha, apenas o índice de entropia acústica teve resultados significativos, apresentando valores mais altos com o aumento do tamanho da área. Para o segundo capítulo, capturamos aves em 13 ilhas de tamanho variável e duas áreas de floresta contínua e analisamos os níveis de corticosterona nas penas de 265 indivíduos de oito espécies diferentes. Nossos resultados não suportam a hipótese de que os níveis de corticosterona variam em relação ao tamanho da ilha, exceto para Hypocnemis cantator, que apresentou diminuição dos níveis de corticosterona com aumento do tamanho da ilha. No geral, concluímos que mesmo em um ambiente altamente diverso, como florestas tropicais, os índices acústicos fornecem uma excelente ferramenta complementar para a avaliação da biodiversidade quando fornecidos com um banco de dados fundamentado. Estudos adicionais são necessários para avaliar a eficiência do uso dos níveis de corticosterona como uma medida fisiológica do estresse e determinar quais parâmetros são úteis para entender como a insularização causada pelas atividades humanas pode influenciar a resistência das populações de aves a distúrbios no habitat

Purification and partial characterization of a new lectin from Parkia panurensis Benth. ex H.C. Hopkins seeds (Leguminosae family; Mimosoideae subfamily) and evaluation of its biological effects

Lectins are proteins that have as one of their main characteristics recognizing and reversibly binding to carbohydrates. In this work, it was possible to purify and characterize a lectin from Parkia panurensis (Leguminosae family; Mimosoideae subfamily) seeds by a combination of the techniques: protein precipitation, along with affinity and then ion exchange chromatography using the Sepharose-mannose and diethylaminoethyl matrices, respectively. The pure lectin, called PpaL, has affinity by D-mannose, D-glucose and derivatives. PpaL was stable over a wide range of temperature and pH, and it showed an SDS-PAGE profile of only one protein band with apparent mass of 45 kDa, subsequently confirmed by mass spectrometry, and presented a molecular mass of 50,566 ± 1 Da. PAGE analysis and molecular exclusion chromatography demonstrated that PpaL is presented as a dimer in solution. Partial sequencing of the primary structure resulted in a total of 334 amino acid residues with approximately 97% similarity to Parkia biglobosa and Parkia platycephala seed lectins. PpaL was shown to be toxic against Artemia nauplii and had an LC50 of 20 µg/mL. The effects of biological activities presented by these proteins make them important biotechnological tools, demonstrating the importance of bioprospection of new lectins. © 2019 Elsevier B.V

Infection and behavior manipulation of social wasps (Vespidae: Polistinae) by Ophiocordyceps humbertii in Neotropical forests: new records of wasp-zombification by a fungus

Ophiocordyceps is a genus comprised by entomopathogenic fungi known to infect ten orders of insects, including Hymenoptera. Amongst the nearly 250 species described in the genus, few are known to manipulate their hosts, which are most notably ants. These species cause their hosts to die in an exposed position high above the ground while grabbing and/or biting the abaxial surface of leaves or branches, which in turn optimizes the fungus spore production and dispersal. Herein, we report on 14 social wasp species belonging to four genera (Agelaia, Mischocyttarus Polybia, and Pseudopolybia) infected by Ophiocordyceps humbertii, a common wasp pathogen. This study broadens the geographic and host range for O. humbertii and provides the first record of its ability to manipulate its host. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group

Analysis of suspended sediment in the Anavilhanas Archipelago, Rio Negro, Amazon Basin

This article analyzes the flows of water and total suspended sediment in different reaches in the lower course of the Negro River, the largest fluvial blackwater system in the world. The area under study is the Anavilhanas Archipelago, which is a complex multichannel reach on the Negro River. Between the years 2016 and 2019, data about water discharge, velocity, and concentration of total suspended solids (TSS) were acquired in sample sections of the Negro River channels located upstream, inside, and downstream of the Anavilhanas Archipelago. In the study area, the Negro River drains an area greater than 700,000 km2, and the mean water discharge observed before the Anavilhanas was about 28.655 m3s1, of which 97% flows through two channels of the Archipelago close to the right and left banks. The mean TSS concentration of the Negro River upstream and downstream the Archipelago was 3.28 mg•L1 and 1.63 mgL1, respectively. Within the Archipelago, we observed more TSS in the channel on the left bank of the Negro River (mean of 4.50 mg•L1). The total suspended sediment discharge of the Negro River before (3.14 Mt•year-1) and after (1.43 Mt•year1) the Anavilhanas Archipelago indicates a 55% retention of the suspended load due to the low water slope and reduced flow velocity caused by the backwater effect of Solimoes River on the Negro River. The hydro-sedimentary scenario of the low course of the Negro River characterized in this study indicates a slow and continuous sedimentation process in the Anavilhanas Archipelago. The results presented will serve as a baseline to assess the impacts of the dams on the Branco River, the main tributary for both water and sediment in the Negro River basin. © 2020 by the authors

Interações biosfera-atmosfera em uma savana tropical no leste da Amazônia

Sensitive heat, latent heat, soil heat and carbon dioxide flux measurements were made in a natural savanna ecosystem in eastern Amazonia, using the eddy covariance method. Data collection was carried out in a savanna area in the municipality of Santarém, Pará, from September to November 2018, a period corresponding to part of the dry season in the region. In this experimental site, the patterns of variability of the daily cycle for energy and CO2 flows were analyzed, as well as an attempt to understand the structure of the local turbulence. The average air temperature in the year 2018 at the savanna site was 29 ºC, being 2 ºC warmer than the historical average of the region, with the occurrence of occasional and low intensity rain episodes. The average radiation balance at the surface was 125 W m-2, with an average daily latent heat flow (LE) in the period of 59 W m-2, while the sensitive heat flow (H) was 69 W m- 2. The average Bowen ratio for the data period was 1.4, representing the preponderance of air heating processes over evaporative processes. During the day, about 36% of the available energy (Rn) in the savanna was used in the evapotranspiration process and H corresponded to 51% of Rn on average. In the study's time interval, an incomplete surface energy balance was observed, with a deficit of 8%. With respect to carbon dioxide flows, the maximum carbon absorption was -8.8 µmol.m-2 s-1, during the day, while the maximum emission was 4.6 µmol.m- 2 s-1 , during dawn. In general, it was found that, in terms of energy balance, the studied savanna has characteristics of a typical savanna, despite the more humid climate in this region compared to other savanna regions. Regarding the structure of turbulence in the savanna atmosphere, it is not possible to apply the Monin-Obukhov Similarity Theory, following the behavior observed in the Amazon rainforest, which requires an adaptation of the theory for the biome in the correct quantification of mass and energy flows.Foram realizadas medidas de fluxos de calor sensível, calor latente, calor no solo e de dióxido de carbono em um ecossistema de savana natural no leste da Amazônia, utilizando o método de covariância de vórtices turbulentos. A coleta de dados foi realizada em uma área de savana no município de Santarém, Pará, de setembro a novembro de 2018, período corresponde à parte da estação seca na região. Neste sítio experimental, os padrões de variabilidade do ciclo diário para os fluxos de energia e CO2 foram analisados, assim como buscou-se conhecer a estrutura da turbulência local. A temperatura média do ar no ano de 2018 no sítio de savana foi de 29 ºC, sendo 2 ºC mais quente que a média histórica da região, com ocorrência de episódios de chuva pontuais e de baixa intensidade. O saldo de radiação médio à superfície foi de 125 W m-2, com fluxo médio diário de calor latente (LE) no período de 59 W m-2, enquanto o fluxo de calor sensível (H) foi de 69 W m-2. A razão de Bowen média para o período de dados foi de 1,4, representando a preponderância dos processos de aquecimento do ar frente aos processos evaporativos. Durante o período diurno, cerca de 36% da energia disponível (Rn) na savana foi utilizada no processo de evapotranspiração e H correspondeu a 51% de Rn em média. No intervalo de tempo do estudo, foi observado um fechamento do balanço de energia à superfície incompleto, com déficit de 8%. Com relação aos fluxos de dióxido de carbono, a máxima absorção de carbono foi de -8,8 µmol.m-2 s-1, durante o dia, enquanto a máxima emissão foi de 4,6 µmol.m-2 s-1, durante o alvorecer. De modo geral, verificou-se que, em termos do balanço de energia, a savana em estudo apresenta características de uma savana típica, apesar do clima mais úmido nessa região comparado a outras regiões de savana. Com relação à estrutura da turbulência na atmosfera em savana, não é possível a aplicação da Teoria da Similaridade de Monin-Obukhov, seguindo o comportamento observado na floresta amazônica, o que requer uma adequação da teoria para o bioma na correta quantificação dos fluxos de massa e energia