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Research about Amazon Basin

Source-linked reports with geographic coverage including Amazon Basin.

4 recordsLinked to original sources
USGS2025

Systematics of three Amazonian antwren groups (Aves: Passeriformes: Thamnophilidae: Myrmotherula and Isleria)

Working within the framework of a companion phylogenetic analysis, we reexamined species limits within three lineages of antwrens (two species and one species complex) widely distributed across the Amazon Basin. Diagnostic differences in vocal and plumage characters provided the basis for the following taxonomic revisions. Myrmotherula longipennis is found to comprise three species: (1) M. longipennis ( sensu stricto ), which is confined to the region north of the Amazon; (2) M. garbei , which is elevated from subspecies status and includes the subspecies zimmeri ; and (3) M. paraensis , which is also elevated from subspecies status and includes subspecies transitiva and ochrogyna . Myrmotherula menetriesii also comprises three species: (1) M. menetriesii ( sensu stricto ), which occurs in the southwest quadrant of Amazonia and includes the subspecies berlepschi ; (2) M. cinereiventris , which is elevated from subspecies status and includes the subspecies pallida ; and (3) M. omissa , which is monotypic and is also elevated from subspecies status. We maintain two species in the Isleria complex, I. guttata and I. hauxwelli . Isleria guttata remains monotypic, but the subspecies of I. hauxwelli are revised. Isleria h. hellmayri is preserved as currently defined, but I. h. suffusa is synonymized with the nominate form, the geographic range of which is restricted to western Amazonia. A fourth subspecies, I. h. clarior , is resurrected; this subspecies occupies the major part of the range previously assigned to I. h. hauxwelli .

Zootaxa↗
USGS2024

The Amazon Basin’s rivers and lakes support Nearctic-breeding shorebirds during southward migration

Identifying the migration routes and stopover sites used by declining species is critical for developing targeted conservation actions. Long-distance migratory shorebirds are among the groups of birds declining most rapidly, yet we frequently lack detailed knowledge about the routes and stopover sites they use during their hemisphere-spanning migrations. This is especially true for species that migrate through mid-continental regions in the Western Hemisphere. We therefore used satellite transmitters to track 212 individuals of 6 shorebird species during their southward migrations— Pluvialis dominica (American Golden-Plover), Limosa haemastica (Hudsonian Godwit), Tringa flavipes (Lesser Yellowlegs), and Calidris subruficollis (Buff-breasted Sandpiper), C. melanotos (Pectoral Sandpiper), and Bartramia longicauda (Upland Sandpiper)—as they crossed the Amazon Basin of South America, a region from which reports of shorebird numbers are increasing but remain relatively rare. Our results make clear that the Amazon Basin provides stopover habitat for a large number of shorebirds: more than 74% of individuals tracked crossing the Amazon Basin stopped over in the region for an average of 2–14 days, with some spending the entire nonbreeding season there. All species selected stopover sites along the region’s many rivers and lakes, while within stopover sites each species exhibited distinct habitat preferences. The timing of stopovers within sub-basins of the Amazon Basin also coincided with periods of low water, when the muddy, shallow water habitats preferred by most shorebirds are likely plentiful. Together, our results highlight the need for detailed investigations into shorebird abundance and distribution within the Amazon Basin, threats to shorebirds within particular subbasins, and links between shorebird conservation efforts and those targeting the myriad other species that inhabit this dynamic, hyper-diverse region.

Amazon Basin↗
USGS2018

Efficiently approximating the Pareto frontier: Hydropower dam placement in the Amazon basin

Real–world problems are often not fully characterized by a single optimal solution, as they frequently involve multiple competing objectives; it is therefore important to identify the so-called Pareto frontier, which captures solution trade-offs. We propose a fully polynomial-time approximation scheme based on Dynamic Programming (DP) for computing a polynomially succinct curve that approximates the Pareto frontier to within an arbitrarily small  > 0 on treestructured networks. Given a set of objectives, our approximation scheme runs in time polynomial in the size of the instance and 1/. We also propose a Mixed Integer Programming (MIP) scheme to approximate the Pareto frontier. The DP and MIP Pareto frontier approaches have complementary strengths and are surprisingly effective. We provide empirical results showing that our methods outperform other approaches in efficiency and accuracy. Our work is motivated by a problem in computational sustainability concerning the proliferation of hydropower dams throughout the Amazon basin. Our goal is to support decision-makers in evaluating impacted ecosystem services on the full scale of the Amazon basin. Our work is general and can be applied to approximate the Pareto frontier of a variety of multiobjective problems on tree-structured networks.

Conference Paper↗