scholarly journals Impacts of a large hydroelectric dam on the Madeira River (Brazil) on floodplain avifauna

2021 ◽  
Vol 51 (4) ◽  
pp. 298-310
Author(s):  
Tomaz Nascimendo de MELO ◽  
Marconi Campos CERQUEIRA ◽  
Fernando Mendonça D’HORTA ◽  
Hanna TUOMISTO ◽  
Jasper Van DONINCK ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Bird Species ◽  
Floodplain Forest ◽  
Dam Construction ◽  
Automated Classification ◽  
Forest Sites ◽  
Madeira River ◽  
Seasonally Flooded ◽  
Successional Vegetation ◽  
Reservoir Filling

ABSTRACT Hydroelectric dams represent an important threat to seasonally flooded environments in the Amazon basin. We aimed to evaluate how a dam in the Madeira River, one of the largest tributaries of the Amazonas River, affected floodplain avifauna. Bird occurrence was recorded through simultaneous passive acoustic monitoring in early successional vegetation and floodplain forest downstream from the dam and upstream in sites impacted by permanent flooding after dam reservoir filling. Species were identified through manual inspection and semi-automated classification of the recordings. To assess the similarity in vegetation between downstream and upstream sites, we used Landsat TM/ETM+ composite images from before (2009-2011) and after (2016-2018) reservoir filling. Downstream and upstream floodplain forest sites were similar before, but not after dam construction. Early successional vegetation sites were already different before dam construction. We recorded 195 bird species. While species richness did not differ between upstream and downstream sites, species composition differed significantly. Ten species were indicators of early successional vegetation upstream, and four downstream. Ten species were indicators of floodplain forest upstream, and 31 downstream. Seven of 24 floodplain specialist species were detected by the semi-automated classification only upstream. While we found some bird species characteristic of early successional vegetation in the upstream sites, we did not find most species characteristic of tall floodplain forest. Predominantly carnivorous, insectivorous, and nectarivorous species appear to have been replaced by generalist and widely distributed species.

What is the avifauna of Amazonian white-sand vegetation?

2015 ◽  
Vol 26 (2) ◽  
pp. 192-204 ◽  
Author(s):  
SÉRGIO HENRIQUE BORGES ◽  
CINTIA CORNELIUS ◽  
CAMILA RIBAS ◽  
RICARDO ALMEIDA ◽  
EDSON GUILHERME ◽  
...  
Keyword(s):  
Environmental History ◽  
Indicator Species ◽  
Amazon Basin ◽  
Vegetation Type ◽  
Bird Species ◽  
White Sand ◽  
Flooded Forests ◽  
Areas Of Endemism ◽  
History Of ◽  
Seasonally Flooded

SummaryWhite-sand vegetation (WSV) is a rare vegetation type in the Amazon basin that grows in nutrient impoverished sandy soils that occur as patches of variable size. Associated with this vegetation is bird assemblage that has not yet been fully characterized. Based on published species inventories and our own field data we compile a checklist of bird species recorded in WSV. In addition, we compared the avifauna of WSV with that found in savanna patches, another type of Amazonian open vegetation. WSV hosted a distinctive avifauna including endemic and threatened species. The number of bird species was lower in WSV compared to nearby terra firme forests, seasonally flooded forests and Amazonian savannas. Despite its low diversity, the avifauna of WSV has a distinctive species composition and makes a significant contribution to Amazonian beta diversity. At least 35 bird species can be considered as indicator species for this environment. Previously identified areas of endemism within the Amazon basin house at least one WSV indicator bird including cases of congeneric species with allopatric distributions. Seven of the WSV indicator species (20% of this avifauna) are in an IUCN threatened category, with one species Polioptila clementsi considered Critically Endangered. Their isolated distribution, small area occupied, and fragility to human-driven disturbances makes WSV one of the most threatened vegetation types in the Amazon basin. The study of WSV avifauna contributes to a better understanding of mechanisms that generate and maintain species diversity as well as of the environmental history of the most biologically diverse biome of the planet.

scholarly journals Response of Understory Avifauna to Annual Flooding of Amazonian Floodplain Forests

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1004
Author(s):  
Anaís Rebeca Prestes Rowedder ◽  
Thiago Orsi Laranjeiras ◽  
Torbjørn Haugaasen ◽  
Benjamin Gilmore ◽  
Mario Cohn-Haft
Keyword(s):  
Amazon Basin ◽  
Bird Species ◽  
Vertical Displacement ◽  
High Water ◽  
Floodplain Forest ◽  
Vertical Position ◽  
Floodplain Forests ◽  
Vegetation Density ◽  
Central Amazonia ◽  
Forest Strata

The annual flooding in the Amazon basin transforms the understory of floodplain forests into an aquatic environment. However, a great number of non-aquatic bird species occupy the understory and midstory of these forests. In general, these birds are thought to be sedentary and territorial, but the way they adapt to this dramatic seasonal transformation has never been described in detail. In this study, we describe avifaunal strategies to cope with seasonal flooding in the lower Purus region, central Amazonia, Brazil. We conducted focal observations of five insectivorous species occupying the lowest forest strata in two types of floodplain forest (black- and whitewater) during the low- and high-water seasons. For each observation, the height of the bird above the substrate (ground or water), its vertical position in the forest, and vegetation density around the bird were noted. All species remained present in the floodplain forests during the two seasons and were not recorded in adjacent unflooded (terra firme) forest. In general, birds migrated vertically to higher forest strata and most species (three of the five) occupied similar vegetation densities independent of water level. Despite the tendency of all species to rise in relative vertical position at high water, there was a reduction in height above substrate for four of the five species, suggesting that their position relative to water was not an important microhabitat element for them. Responses were similar in the two floodplain forest types. It is likely that the decrease in available space during the flood, combined with similar vertical displacement in arthropods, leads to increased prey density for understory insectivorous birds and permits year-round territoriality without major habitat shifts.

scholarly journals Diversity and host assemblage of avian haemosporidians in different terrestrial ecoregions of Peru

2021 ◽  
Author(s):  
Luz Garcia-Longoria ◽  
Jaime Muriel ◽  
Sergio Magallanes ◽  
Zaira Hellen Villa-Galarce ◽  
Leonila Ricopa ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Evolutionary Dynamics ◽  
Bird Species ◽  
Host Community ◽  
Bird Diversity ◽  
New Host ◽  
Parasite Richness ◽  
Haemosporidian Parasites ◽  
Avian Haemosporidians ◽  
Host Parasite

Abstract Characterizing the diversity and structure of host-parasite communities is crucial to understanding their eco-evolutionary dynamics. Malaria and related haemosporidian parasites are responsible for fitness loss and mortality in bird species worldwide. However, despite exhibiting the greatest ornithological biodiversity, avian haemosporidians from Neotropical regions are quite unexplored. Here, we analyse the genetic diversity of bird haemosporidian parasites (Plasmodium and Haemoproteus) in 1,336 individuals belonging to 206 bird species to explore for differences in diversity of parasite lineages and bird species across five well-differentiated Peruvian ecoregions. We detected 70 different haemosporidian lineages infecting 74 bird species. We showed that 25 out of the 70 haplotypes had not been previously recorded. Moreover, we also identified 81 new host – parasite interactions representing new host records for these haemosporidian parasites. Our outcomes revealed that the effective diversity (as well as the richness, abundance, and Shannon-Weaver index) for both birds and parasite lineages was higher in Amazon basin ecoregions. Furthermore, we also showed that ecoregions with greater diversity of bird species also had high parasite richness, hence suggesting that host community is crucial in explaining parasite richness. Generalist parasites were found in ecoregions with lower bird diversity, implying that the abundance and richness of hosts may shape the exploitation strategy followed by haemosporidian parasites. These outcomes reveal that Neotropical region is a major reservoir of unidentified haemosporidian lineages. Further studies analysing host distribution and specificity of these parasites in the tropics will provide important knowledge about phylogenetic relationships, phylogeography, and patterns of evolution and distribution of haemosporidian parasites.

Evidence for changes in the dynamics of Earth crust tilts caused by the large dam construction and reservoir filling at the Enguri dam international test area (Georgia)

2011 ◽  
Vol 66 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Teimuraz Matcharashvili ◽  
Tamaz Chelidze ◽  
Vakhtang Abashidze ◽  
Natalia Zhukova ◽  
Ekaterine Mepharidze ◽  
...  
Keyword(s):  
Test Area ◽  
Dam Construction ◽  
Reservoir Filling ◽  
Large Dam

scholarly journals Evaluating the effect of nutrient redistribution by animals on the phosphorus cycle of lowland Amazonia

2018 ◽  
Vol 15 (1) ◽  
pp. 279-295 ◽  
Author(s):  
Corina Buendía ◽  
Axel Kleidon ◽  
Stefano Manzoni ◽  
Björn Reu ◽  
Amilcare Porporato
Keyword(s):  
Amazon Basin ◽  
P Availability ◽  
Phosphorus Cycle ◽  
Terra Firme ◽  
The Andes ◽  
P Content ◽  
Spatial Redistribution ◽  
Soil Age ◽  
Seasonally Flooded ◽  
Lowland Amazonia

Abstract. Phosphorus (P) availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland) ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.

scholarly journals Morphologically cryptic Amazonian bird species pairs exhibit strong postzygotic reproductive isolation

2018 ◽  
Vol 285 (1874) ◽  
pp. 20172081 ◽  
Author(s):  
Paola Pulido-Santacruz ◽  
Alexandre Aleixo ◽  
Jason T. Weir
Keyword(s):  
Reproductive Isolation ◽  
Amazon Basin ◽  
Species Recognition ◽  
Bird Species ◽  
Hybrid Zones ◽  
Hybrid Index ◽  
Postzygotic Isolation ◽  
Genome Wide ◽  
Species Pairs ◽  
Hybrid Classes

We possess limited understanding of how speciation unfolds in the most species-rich region of the planet—the Amazon basin. Hybrid zones provide valuable information on the evolution of reproductive isolation, but few studies of Amazonian vertebrate hybrid zones have rigorously examined the genome-wide underpinnings of reproductive isolation. We used genome-wide genetic datasets to show that two deeply diverged, but morphologically cryptic sister species of forest understorey birds show little evidence for prezygotic reproductive isolation, but substantial postzygotic isolation. Patterns of heterozygosity and hybrid index revealed that hybrid classes with heavily recombined genomes are rare and closely match simulations with high levels of selection against hybrids. Genomic and geographical clines exhibit a remarkable similarity across loci in cline centres, and have exceptionally narrow cline widths, suggesting that postzygotic isolation is driven by genetic incompatibilities at many loci, rather than a few loci of strong effect. We propose Amazonian understorey forest birds speciate slowly via gradual accumulation of postzygotic genetic incompatibilities, with prezygotic barriers playing a less important role. Our results suggest old, cryptic Amazonian taxa classified as subspecies could have substantial postzygotic isolation deserving species recognition and that species richness is likely to be substantially underestimated in Amazonia.

scholarly journals Triplodon chodo, a new species of pearly fresh water mussel from the Amazon Basin (Mollusca: Bivalvia: Unionoida: Hyriidae)

2008 ◽  
Vol 25 (1) ◽  
pp. 111-115 ◽  
Author(s):  
Maria C. D. Mansur ◽  
Daniel M. Pimpão
Keyword(s):  
New Species ◽  
Amazon Basin ◽  
Shell Height ◽  
Anterior Region ◽  
Obtuse Angle ◽  
Madeira River ◽  
Amazonas State ◽  
The Guianas ◽  
A New Species ◽  
Madeira River Basin

A new species of the genus Triplodon Spix, 1827 is described based on shell samples collected on Rivers Jamari (Rondônia State) and Aripuanã (Amazonas State) from the Madeira River Basin; on the Amazon at Oriximiná and on the mouth of Tapajós River at Alter do Chão (Pará State). Triplodon chodo is a new species considered closely related to T. stevensi Lea, 1871, (described from the part of the River Essequibo which borders the Guianas). Triplodon chodo is distinguished from the latter by its smaller, lighter shell, the absence of a wing in the anterior region and by the delicate shape of the external sculpture, which is composed of minuscule nodules organized in rows that converge and crosses on the centre of the valves. The straight and vertical posterior margin forms a right or slightly obtuse angle with the shell's dorsal and ventral margins. The anterior region is short, low and slightly tapering, with the distal extremity situated on the half of the shell height. The dorsal and ventral margins are equally curved.

Effects of natural rapids and waterfalls on fish assemblage structure in the Madeira River (Amazon Basin)

2011 ◽  
Vol 20 (4) ◽  
pp. 588-597 ◽  
Author(s):  
Gislene Torrente-Vilara ◽  
Jansen Zuanon ◽  
Fabien Leprieur ◽  
Thierry Oberdorff ◽  
Pablo A. Tedesco
Keyword(s):  
Fish Assemblage ◽  
Amazon Basin ◽  
Assemblage Structure ◽  
Fish Assemblage Structure ◽  
Madeira River

scholarly journals Age and growth of the Amazonian migratory catfish Brachyplatystoma rousseauxii in the Madeira River basin before the construction of dams

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Marília Hauser ◽  
Carolina R. C. Doria ◽  
Larissa R. C. Melo ◽  
Ariel R. Santos ◽  
Daiana M. Ayala ◽  
...  
Keyword(s):  
River Basin ◽  
Amazon Basin ◽  
Growth Parameters ◽  
Growth Patterns ◽  
Age And Growth ◽  
Growth Rings ◽  
Madeira River ◽  
Lower Maximum ◽  
Future Evaluation ◽  
Madeira River Basin

ABSTRACT The goliath catfish Brachyplatystoma rousseauxii has crucial economical and ecological functions in the Amazon basin. Although its life history characteristics have been studied in the Amazon, there is little information in the Madeira River basin, which holds genetically distinct populations and where dams were recently built. Using fish collected in Bolivia, Brazil and Peru, this study provides a validation of growth rings deposition and details the growth patterns of B. rousseauxii in the Madeira before the dams’ construction. Age structure and growth parameters were determined from 497 otolith readings. The species exhibits two growth rings per year and sampled fish were between 0 and 16 years old. In the Brazilian portion of the basin, mainly young individuals below 5 years old were found, whereas older fish (> 5 years) were caught only in the Bolivian and Peruvian stretches, indicating that after migrating upstream to reproduce, adults remain in the headwaters of the Madeira River. Comparing with previous publications, B. rousseauxii had a slower growth and 20 cm lower maximum standard length in the Madeira River than in the Amazon River. This study provides a baseline for future evaluation of changes in population dynamics of the species following dams closure.

scholarly journals Habitat and population estimates of some threatened lowland forest bird species in Tambopata, south-east Peru

2004 ◽  
Vol 14 (4) ◽  
pp. 261-277 ◽  
Author(s):  
HUW LLOYD
Keyword(s):  
Bird Species ◽  
Selective Logging ◽  
Floodplain Forest ◽  
Primary Forest ◽  
Population Estimates ◽  
Lowland Forest ◽  
Density Estimates ◽  
Forest Bird ◽  
Madre De Dios ◽  
Forest Habitats

Surveys of threatened lowland forest bird species and forest habitats were conducted during a 21-month census of lowland bird communities in Tambopata, Department of Madre de Dios, south-east Peru. A combination of distance sampling census methods and direct counts was used for the census in five sites located along the Rio Madre de Dios and Rio Tambopata. All five sites consisted of different forest types with significantly different habitat components. Three of these sites were classified as primary forest habitats whilst the remaining two were classified as disturbed forests. Population densities were calculated for eight of the threatened species recorded during the census. Density estimates of non-bamboo specialists were higher in primary forest habitats than in disturbed forest habitats. Density estimates of most bamboo specialists were higher in primary Old Floodplain forest with extensive bamboo understorey than in primary Middle/Upper Floodplain forest with smaller, patchy areas of bamboo understorey. Calculation of regional population estimates based on the amount of forest cover from satellite photographs shows that only two of the threatened bird species have substantial populations currently protected by the Parque Nacional Bahuaja-Sonene and Reservada Nacional de Tambopata. Selective logging operations that reduce overall tree biomass and remove a large proportion of palm tree species from primary forest habitats will have an adverse affect on local populations of four of the threatened bird species in the region.

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