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1
Bush, M. B., M. R. Silman, C. McMichael y S. Saatchi. "Fire, climate change and biodiversity in Amazonia: a Late-Holocene perspective". Philosophical Transactions of the Royal Society B: Biological Sciences 363, n.º 1498 (11 de febrero de 2008): 1795–802. http://dx.doi.org/10.1098/rstb.2007.0014.
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Fire is an important and arguably unnatural component of many wet Amazonian and Andean forest systems. Soil charcoal has been used to infer widespread human use of landscapes prior to European Conquest. An analysis of Amazonian soil carbon records reveals that the records have distinct spatial and temporal patterns, suggesting that either fires were only set in moderately seasonal areas of Amazonia or that strongly seasonal and aseasonal areas are undersampled. Synthesizing data from 300 charcoal records, an age–frequency diagram reveals peaks of fire apparently coinciding with some periods of very strong El Niño activity. However, the El Niño record does not always provide an accurate prediction of fire timing, and a better match is found in the record of insolation minima. After the time of European contact, fires became much scarcer within Amazonia. In both the Amazonia and the Andes, modern fire pattern is strongly allied to human activity. On the flank of the Andes, forests that have never burned are being eroded by fire spreading downslope from grasslands. Species of these same forests are being forced to migrate upslope due to warming and will encounter a firm artificial fire boundary of human activity.
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Nores, Manuel. "The Western Amazonian Boundary for Avifauna Determined by Species Distribution Patterns and Geographical and Ecological Features". International Journal of Ecology 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/958684.
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In northern South America, an extensive tropical lowland runs 5,000 km from the Atlantic coast to the foot of the Andes. The slope is gentle until about 500 m where the eastern Andes rise abruptly. The lowland supports Amazonia, which is the most extensive tract of tropical rainforest on the planet. Most of its boundaries are well defined, but the boundary between Amazonia and the forest of the eastern slopes of the Andes has not been clearly defined. To determine for avifauna whether Amazonia is restricted to the lowland of northern South America or whether it also extends up into the eastern slopes of the Andes, different types of data were used. The results indicate that Amazonia may be restricted to the lowland that extends from the Atlantic coast to the foot of the Andes, up to about 500 m. Consequently, the number of bird species strictly endemic to Amazonia would be 290. Comparison with the distribution of vegetation on the eastern slopes of the Andes also suggests that Amazonia as a biome may be restricted to the lowland that extends from the Atlantic coast to the foot of the Andes, up to about 500 m.
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Borda, Víctor, Isabela Alvim, Marla Mendes, Carolina Silva-Carvalho, Giordano B. Soares-Souza, Thiago P. Leal, Vinicius Furlan et al. "The genetic structure and adaptation of Andean highlanders and Amazonians are influenced by the interplay between geography and culture". Proceedings of the National Academy of Sciences 117, n.º 51 (4 de diciembre de 2020): 32557–65. http://dx.doi.org/10.1073/pnas.2013773117.
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Western South America was one of the worldwide cradles of civilization. The well-known Inca Empire was the tip of the iceberg of an evolutionary process that started 11,000 to 14,000 years ago. Genetic data from 18 Peruvian populations reveal the following: 1) The between-population homogenization of the central southern Andes and its differentiation with respect to Amazonian populations of similar latitudes do not extend northward. Instead, longitudinal gene flow between the northern coast of Peru, Andes, and Amazonia accompanied cultural and socioeconomic interactions revealed by archeology. This pattern recapitulates the environmental and cultural differentiation between the fertile north, where altitudes are lower, and the arid south, where the Andes are higher, acting as a genetic barrier between the sharply different environments of the Andes and Amazonia. 2) The genetic homogenization between the populations of the arid Andes is not only due to migrations during the Inca Empire or the subsequent colonial period. It started at least during the earlier expansion of the Wari Empire (600 to 1,000 years before present). 3) This demographic history allowed for cases of positive natural selection in the high and arid Andes vs. the low Amazon tropical forest: in the Andes, a putative enhancer inHAND2-AS1(heart and neural crest derivatives expressed 2 antisense RNA1, a noncoding gene related to cardiovascular function) and rs269868-C/Ser1067 inDUOX2(dual oxidase 2, related to thyroid function and innate immunity) genes and, in the Amazon, the gene encoding for the CD45 protein, essential for antigen recognition by T and B lymphocytes in viral–host interaction.
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STURARO, MARCELO JOSÉ y TERESA C. S. AVILA-PIRES. "Taxonomic revision of the geckos of the Gonatodes concinnatus complex (Squamata: Sphaerodactylidae), with description of two new species". Zootaxa 2869, n.º 1 (6 de mayo de 2011): 1. http://dx.doi.org/10.11646/zootaxa.2869.1.1.
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The Gonatodes concinnatus complex, as here considered, consists of Gonatodes species characterized by a white suprahumeral spot with black margins; vermiculations or not on back; and transversely enlarged scales under the tail, showing the sequence 1’1’1”, and in some specimens 1’1’2” on the anterior portion. Two species are presently recognized in this Amazonian complex: G. concinnatus and G. tapajonicus. New material collected in eastern Amazonia (states of Pará and Amapá, Brazil) made it necessary to review these species. We analyzed several populations within this complex, from Colombia, Ecuador, Peru, Venezuela and Brazil, including these new records. Specimens were separated in groups defined on basis of color pattern. Stepwise discriminant function analyses were then performed to compare the external morphology (measurements and scale counts) in these groups. Results support recognition of five taxa, corresponding to G. concinnatus from western Amazonia, in Ecuador and northern Peru; G. ligiae from northwestern Venezuela (east of the Andes); G. tapajonicus, from the Tapajós river basin, in Pará, Brazil; and two new species, one from eastern Amazonia, in the states of Pará (north and south of the Amazon river) and Amapá, Brazil, and another from central Colombia, east of the Andes. Diagnoses and descriptions of all species are presented.
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Lombardo, Umberto. "Alluvial plain dynamics in the southern Amazonian foreland basin". Earth System Dynamics 7, n.º 2 (10 de mayo de 2016): 453–67. http://dx.doi.org/10.5194/esd-7-453-2016.
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Abstract. Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation is primarily the result of river crevasse splays and sheet sands triggered by above-normal precipitation events due to La Niña. However, more than 90 % of the Amazonian river network is made of small rivers and it is unknown whether small river floodplain sedimentation is influenced by the ENSO cycle as well. Using Landsat images from 1984 to 2014, here I analyse the behaviour of all 12 tributaries of the Río Mamoré with a catchment in the Andes. I show that these are very active rivers and that the frequency of crevasses is not linked to ENSO activity. The data suggest that most of the sediments eroded from the Andes by the tributaries of the Mamoré are deposited in the alluvial plains, before reaching the parent river. The mid-to-late Holocene paleo-channels of these rivers are located tens of kilometres further away from the Andes than the modern crevasses. I conclude that the frequency of crevasses is controlled by intrabasinal processes that act on a yearly to decadal timescale, while the average location of the crevasses is controlled by climatic or neo-tectonic events that act on a millennial scale. Finally, I discuss the implications of river dynamics on rural livelihoods and biodiversity in the Llanos de Moxos, a seasonally flooded savannah covering most of the southern Amazonian foreland basin and the world's largest RAMSAR site.
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Lombardo, U. "Alluvial plain dynamics in the southern Amazonian foreland basin". Earth System Dynamics Discussions 6, n.º 2 (20 de octubre de 2015): 2063–100. http://dx.doi.org/10.5194/esdd-6-2063-2015.
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Abstract. Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation is primarily the result of river crevasse splays triggered by above normal precipitation events due to La Niña. However, more than 90 % of the Amazonian river network is made of small rivers and it is unknown whether small river floodplain sedimentation is influenced by the ENSO cycle as well. Using Landsat images from 1984 to 2014, here I analyse the behaviour of all the twelve tributaries of the Río Mamoré with a catchment in the Andes. I show that these are very active rivers and that the frequency of crevasses is not linked to ENSO activity. I found that most of the sediments eroded from the Andes by the tributaries of the Mamoré are deposited in the alluvial plains, before reaching the parent river. The mid- to late Holocene paleo-channels of these rivers are located tens of kilometres further away from the Andes than the modern crevasses. I conclude that the frequency of crevasses is controlled by intrabasinal processes that act on a year to decade time scale, while the average location of the crevasses is controlled by climatic or neo-tectonic events that act on a millennial scale. Finally, I discuss the implications of river dynamics on rural livelihoods and biodiversity in the Llanos de Moxos, a seasonally flooded savannah covering most of the southern Amazonian foreland basin and the world's largest RAMSAR site.
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Canal, Dubán, Nils Köster, Marcela Celis, Thomas B. Croat, Thomas Borsch y Katy E. Jones. "Out of Amazonia and Back Again: Historical Biogeography of the Species-Rich Neotropical Genus Philodendron (Araceae)". Annals of the Missouri Botanical Garden 104, n.º 1 (7 de marzo de 2019): 49–68. http://dx.doi.org/10.3417/2018266.
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The origin of Neotropical species diversity is strongly associated with the geological history of South America. Since the Miocene, a number of species radiations across different Neotropical lineages coincided with the rise of the Andes and the formation of the Isthmus of Panama. The species-rich genus Philodendron Schott (Araceae) is widely distributed across Neotropical rainforests, originating in the Late Oligocene and diversifying more intensely from the Miocene onward. It is likely that its diversification process and distribution patterns are associated with recent geological changes in the Americas. To test this hypothesis, we sampled the species diversity of Philodendron across its entire geographic range and used a combination of three non-coding plastid regions (petD, rpl16, and trnK/matK) to obtain a comprehensive time-calibrated phylogeny. We then inferred geographic range evolution and explored the impact of the Andean orogeny on speciation, extinction, and dispersal. The genus Philodendron originated ~29 million years ago (mya) and experienced the earliest diversification events ~25 mya in the Pan-Amazonian rainforests. From the Middle Miocene onward, multiple geographic range expansion events occurred from Amazonia to southeast Brazil and to the area which would become the Chocó and the northern Andes. From the Pliocene onward, Philodendron reached Central America and the Caribbean islands, and Andean lineages recolonized and diversified in Amazonia. In Philodendron, higher diversification rates are found in the adjacent lowland rainforests of the northern Andes compared with other regions in the Neotropics, demonstrating a potential indirect impact of the Andean uplift on species radiations in lowland regions.
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IRMLER, ULRICH. "New species and records of the genus Lispinus with a key to the species from Peru (Coleoptera: Staphylinidae: Osoriinae)". Zootaxa 2263, n.º 1 (13 de octubre de 2009): 42–58. http://dx.doi.org/10.11646/zootaxa.2263.1.4.
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Four new species of Lispinus from the premontane forest of the eastern slope of the Peruvian Andes are described and records of all other Lispinus species from Peru are given. The new species are: L. blandus, L. minimus, L. speciosus, and L. peruanus. A key to the known 21 Peruvian species is provided, habitat information is summarized and geographical distribution of species is discussed. The following six types of zoogeographic distribution can be differentiated for the Peruvian Lispinus species: endemic, eastern Andean, lowland Amazonian, Circum-Amazonian, northern Southand Central-American, and Pan-Neotropical.
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Govin, A., C. M. Chiessi, M. Zabel, A. O. Sawakuchi, D. Heslop, T. Hörner, Y. Zhang y S. Mulitza. "Terrigenous input off northern South America driven by changes in Amazonian climate and the North Brazil Current retroflection during the last 250 ka". Climate of the Past 10, n.º 2 (28 de abril de 2014): 843–62. http://dx.doi.org/10.5194/cp-10-843-2014.
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Abstract. We investigate changes in the delivery and oceanic transport of Amazon sediments related to terrestrial climate variations over the last 250 ka. We present high-resolution geochemical records from four marine sediment cores located between 5 and 12° N along the northern South American margin. The Amazon River is the sole source of terrigenous material for sites at 5 and 9° N, while the core at 12° N receives a mixture of Amazon and Orinoco detrital particles. Using an endmember unmixing model, we estimated the relative proportions of Amazon Andean material ("%-Andes", at 5 and 9° N) and of Amazon material ("%-Amazon", at 12° N) within the terrigenous fraction. The %-Andes and %-Amazon records exhibit significant precessional variations over the last 250 ka that are more pronounced during interglacials in comparison to glacial periods. High %-Andes values observed during periods of high austral summer insolation reflect the increased delivery of suspended sediments by Andean tributaries and enhanced Amazonian precipitation, in agreement with western Amazonian speleothem records. Increased Amazonian rainfall reflects the intensification of the South American monsoon in response to enhanced land–ocean thermal gradient and moisture convergence. However, low %-Amazon values obtained at 12° N during the same periods seem to contradict the increased delivery of Amazon sediments. We propose that reorganizations in surface ocean currents modulate the northwestward transport of Amazon material. In agreement with published records, the seasonal North Brazil Current retroflection is intensified (or prolonged in duration) during cold substages of the last 250 ka (which correspond to intervals of high DJF or low JJA insolation) and deflects eastward the Amazon sediment and freshwater plume.
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Reyes-Puig, Juan Pablo, Miguel Urgilés-Merchán, Daniela Franco-Mena, Juan M. Guayasamin, Diego Batallas y Carolina Reyes-Puig. "Two new species of terrestrial frogs of the Pristimantis gladiator complex (Anura, Strabomantidae) from the Ecuadorian Andes, with insights on their biogeography and skull morphology". ZooKeys 1180 (26 de septiembre de 2023): 257–93. http://dx.doi.org/10.3897/zookeys.1180.107333.
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The explosive diversity of rainfrogs (Pristimantis spp) reaches its highest levels in the mountains of the Tropical Andes, with remarkable cryptic species mainly in unexplored areas of Ecuador. Based on phylogenetics, morphometric traits, skull osteology and bioacoustics, we describe two new species of Pristimantis, previously confused with Pristimantis gladiator, that belong to the subgenus Trachyphrynus traditionally known as the Pristimantis myersi species group. The two new taxa are closely related, but have allopatric distributions. We discuss the importance of the Quijos and Pastaza River valleys in the diversification along Amazonian slopes of the Ecuadorian Andes.
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Robinson, S. K., J. W. Fitzpatrick y J. Terborgh. "Distribution and habitat use of Neotropical migrant landbirds in the Amazon basin and Andes". Bird Conservation International 5, n.º 2-3 (septiembre de 1995): 305–23. http://dx.doi.org/10.1017/s0959270900001064.
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SummaryWe documented the geographical distributions and habitat selection of Neotropical migrants in South America along a successional gradient in the lowlands of Amazonian Peru, and along elevational gradients in the Andes of south-eastern Peru and of eastern and western Ecuador. Most of the 30 species of northern migrants that regularly winter in South America appear to be concentrated in the western edge of the Amazon basin and on the lower slopes (2,000 m) of the Andes. Migrants in a lowland site were documented more often in early successional habitats than in primary forest, and no species were confined to mature forest habitats. The number of species and relative abundance of migrants in primary forest, however, increased with elevation up to about 1,200 m and decreased above that elevation. Several species (Contopus borealis, Dendroica cerulea and Wilsonia canadensis) were largely confined to primary forest in the 1,000-2,000 m elevational zones in both Peru and Ecuador. Migrants on the western slope of the Ecuadorean Andes included several species that primarily winter further north. In general, the species richness of migrants and residents was inversely correlated, both on a biogeographical and a local scale. Migratory birds are most likely to be adversely affected by deforestation of the lower slopes of the Andes, which is proceeding at a rapid pace. The impact of human alterations of Amazonian forests will be greater on resident than on migratory birds. The loss of mid-successional lowland forests, however, might have a negative effect on several species.
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Trujillo, William, Edwin Trujillo Trujillo, Fausto Andrés Ortiz-Morea, Diego A. Toro y M. Alejandra Jaramillo. "New Piper species from the eastern slopes of the Andes in northern South America". PhytoKeys 206 (26 de agosto de 2022): 25–48. http://dx.doi.org/10.3897/phytokeys.206.75971.
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We describe four new species of Piper from the Amazonian slopes of the northern Andes. Piper hoyoscardozii is distinguished from similar climbing species, P. dryadum and P. flagellicuspe, by its longer peduncles. The Amazonian species Piper indiwasii is distinguished from P. scutilimbum from Panama and northern Colombia by the narrowly spatulate leaf base extension. Piper nokaidoyitau is characterised by the presence of larger leaves and longer spikes than similar species, P. anonifolium and P. hostmannianum. Finally, P. velae is characterised by cordulate leaf bases in all nodes, petioles 0.8–1.5 cm long and pubescent fruits, which easily distinguish it from the related species, P. holdridgeanum.
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VENEGAS, PABLO J., LUIS A. GARCÍA-AYACHI, JUAN C. CHÁVEZ-ARRIBASPLATA y ANTONIO GARCÍA-BRAVO. "Four new species of polychromatic spiny-tailed iguanian lizards, genus Stenocercus (Iguania: Tropiduridae), from Peru". Zootaxa 5115, n.º 1 (11 de marzo de 2022): 1–28. http://dx.doi.org/10.11646/zootaxa.5115.1.1.
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The tropical Andes Mountains exhibit high levels of endemism and spatial turnover in the distribution of species. The lizard genus Stenocercus Duméril & Bibron, 1837, contains 76 species and most of them occur in the tropical Andes, reaching elevations up to 4,000 m. We describe four new species of Stenocercus based on the examination of newly collected material from the Amazonian slopes of the Peruvian Andes. Stenocercus asenlignus sp. nov. inhabits the premontane forest of northern and central Peru, departments of Amazonas, San Martín and Huánuco, at elevations between 1,500 and 2,036 m, in the basins of the Mayo, Huayabamba, and Huallaga rivers. Stenocercus leybachi sp. nov. inhabits the premontane forest of the upper Huallaga River, Huánuco department in central Peru, at elevations between 824 and 1,270 m. Stenocercus qalaywasi sp. nov. was collected in a small village at the headwaters of the Mantaro River, Junín department in central Peru, at an elevation of 2,587 m. Finally, S. nigrocaudatus sp. nov. inhabits the montane forest from extreme northern Peru, Cajamarca department, at elevations of 1,700 and 1,892 m. These species are characterized by having granular scales on the posterior surface of the thighs, relatively short tail, caudals spinose, two caudal whorls per autotomic segment, and the ability to change coloration from green to brown or gray; they differ from other species of Stenocercus in scutellation features and color pattern.
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Solano-Ugalde, Alejandro y Galo J. Real-Jibaja. "New distributional bird records from the eastern Andean slopes of Ecuador". Check List 6, n.º 2 (1 de junio de 2010): 326. http://dx.doi.org/10.15560/6.2.326.
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Distribution of birds is dynamic. Understanding, documentation and appropriate use of new records are essential, especially when managing threatened species. Here we present novel data regarding new distributional records for 17 bird species along the Amazonian slopes of the eastern Ecuadorian Andes. The new records fill gaps on our knowledge in the distribution, both in latitude and altitude.
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Barbieri, Chiara, Rodrigo Barquera, Leonardo Arias, José R. Sandoval, Oscar Acosta, Camilo Zurita, Abraham Aguilar-Campos et al. "The Current Genomic Landscape of Western South America: Andes, Amazonia, and Pacific Coast". Molecular Biology and Evolution 36, n.º 12 (27 de julio de 2019): 2698–713. http://dx.doi.org/10.1093/molbev/msz174.
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Abstract Studies of Native South American genetic diversity have helped to shed light on the peopling and differentiation of the continent, but available data are sparse for the major ecogeographic domains. These include the Pacific Coast, a potential early migration route; the Andes, home to the most expansive complex societies and to one of the most widely spoken indigenous language families of the continent (Quechua); and Amazonia, with its understudied population structure and rich cultural diversity. Here, we explore the genetic structure of 176 individuals from these three domains, genotyped with the Affymetrix Human Origins array. We infer multiple sources of ancestry within the Native American ancestry component; one with clear predominance on the Coast and in the Andes, and at least two distinct substrates in neighboring Amazonia, including a previously undetected ancestry characteristic of northern Ecuador and Colombia. Amazonian populations are also involved in recent gene-flow with each other and across ecogeographic domains, which does not accord with the traditional view of small, isolated groups. Long-distance genetic connections between speakers of the same language family suggest that indigenous languages here were spread not by cultural contact alone. Finally, Native American populations admixed with post-Columbian European and African sources at different times, with few cases of prolonged isolation. With our results we emphasize the importance of including understudied regions of the continent in high-resolution genetic studies, and we illustrate the potential of SNP chip arrays for informative regional-scale analysis.
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Poulsen, Bent Otto. "Structure, dynamics, home range and activity pattern of mixed-species bird flocks in a montane alder-dominated secondary forest in Ecuador". Journal of Tropical Ecology 12, n.º 3 (mayo de 1996): 333–43. http://dx.doi.org/10.1017/s0266467400009524.
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ABSTRACTTwo mixed-species bird flocks were studied in a high-altitude humid secondary forest in the Andes of Ecuador. Birds were mist-netted and colour-ringed for individual identification. The flocks (A and B) were followed to record structure, dynamics, home range and activity pattern. All observations of the two flocks studied included members from all vertical levels, which is different from flocks of Amazonia. In two nucleus species, some individuals alternated between the flocks, a feature not previously reported. Various tanagers were loosely associated, joining and leaving flocks. Minimum home-range sizes of flocks A and B were 4.2 ha and 7.8 ha, respectively. Some individuals of two species used an area encompassing the home ranges of both flocks. Mean flock sizes in A and B were 21.7 and 44.7 individuals, whereas the mean numbers of species were 13.7 and 21.7, respectively. Number of species and individuals were high compared to even most lowland flocks. Altogether, mixed-species flocks in different habitats and at various latitudinal and altitudinal sites appear to have some features in common, but others are highly distinct. Compared to the great stability of Amazonian flocks, some high-altitude flocks of secondary forest in the Andes appear to be more dynamic and unstable.
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Hoorn, Carina, Lydian M. Boschman, Tyler Kukla, Matteo Sciumbata y Pedro Val. "The Miocene wetland of western Amazonia and its role in Neotropical biogeography". Botanical Journal of the Linnean Society 199, n.º 1 (5 de febrero de 2022): 25–35. http://dx.doi.org/10.1093/botlinnean/boab098.
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Abstract In the Miocene (23–5 Ma), a large wetland known as the Pebas System characterized western Amazonia. During the Middle Miocene Climatic Optimum (c. 17–15 Ma), this system reached its maximum extent and was episodically connected to the Caribbean Sea, while receiving sediment input from the Andes in the west, and the craton (continental core) in the east. Towards the late Miocene (c. 10 Ma) the wetland transitioned into a fluvial-dominated system. In biogeographic models, the Pebas System is often considered in two contexts: one describing the system as a cradle of speciation for aquatic or semi-aquatic taxa such as reptiles, molluscs and ostracods, and the other describing the system as a barrier for dispersal and gene flow for amphibians and terrestrial taxa such as plants, insects and mammals. Here we highlight a third scenario in which the Pebas System is a permeable biogeographical system. This model is inspired by the geological record of the mid-Miocene wetland, which indicates that sediment deposition was cyclic and controlled by orbital forcing and sea-level change, with environmental conditions repeatedly altered. This dynamic landscape favoured biotic exchange at the interface of (1) aquatic and terrestrial, (2) brackish and freshwater and (3) eutrophic to oligotrophic conditions. In addition, the intermittent connections between western Amazonia and the Caribbean Sea, the Andes and eastern Amazonia favoured two-way migrations. Therefore, biotic exchange and adaptation was probably the norm, not the exception, in the Pebas System. The myriad of environmental conditions contributed to the Miocene Amazonian wetland system being one of the most species-rich systems in geological history.
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Govin, A., C. M. Chiessi, M. Zabel, A. O. Sawakuchi, D. Heslop, T. Hörner, Y. Zhang y S. Mulitza. "Terrigenous input off northern South America driven by changes in Amazonian climate and the North Brazil Current retroflection during the last 250 ka". Climate of the Past Discussions 9, n.º 5 (25 de octubre de 2013): 5855–98. http://dx.doi.org/10.5194/cpd-9-5855-2013.
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Abstract. We investigate changes in the delivery and oceanic transport of Amazon sediments related to terrestrial climate variations over the last 250 ka. We present high-resolution geochemical records from four marine sediment cores located between 5 and 12° N along the northern South American margin. The Amazon River is the sole source of terrigenous material for sites at 5 and 9° N, while the core at 12° N receives a mixture of Amazon and Orinoco detrital particles. Using an endmember unmixing model, we estimated the relative proportions of Amazon Andean material ("%-Andes", at 5 and 9° N) and of Amazon material ("%-Amazon", at 12° N) within the terrigenous fraction. The %-Andes and %-Amazon records exhibit significant precessional variations over the last 250 ka that are more pronounced during interglacials in comparison to glacial times. High %-Andes values observed during periods of high austral summer insolation reflect the increased delivery of suspended sediments by Andean tributaries and enhanced Amazonian precipitation, in agreement with western Amazonian speleothem records. However, low %-Amazon values obtained at 12° N during the same periods seem to contradict the increased delivery of Amazon sediments. We propose that reorganisations in surface ocean currents modulate the northwestward transport of Amazon material. In agreement with published records, the seasonal North Brazil Current retroflection is intensified (or prolonged in duration) during cold substages of the last 250 ka (which correspond to intervals of high DJF or low JJA insolation) and deflects eastward the Amazon sediment and freshwater plume.
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Buendía, Corina, Axel Kleidon, Stefano Manzoni, Björn Reu y Amilcare Porporato. "Evaluating the effect of nutrient redistribution by animals on the phosphorus cycle of lowland Amazonia". Biogeosciences 15, n.º 1 (12 de enero de 2018): 279–95. http://dx.doi.org/10.5194/bg-15-279-2018.
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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.
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BRAVO, FREDDY y DAVID SALAZAR-VALENZUELA. "A new species of Sycorax Curtis (Diptera, Psychodidae, Sycoracinae) collected on harlequin frogs (Anura: Bufonidae, Atelopus) in the Ecuadorian Andes". Zootaxa 2093, n.º 1 (6 de mayo de 2009): 37–42. http://dx.doi.org/10.11646/zootaxa.2093.1.2.
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Sycorax wampukrum sp. nov. is described from the Amazonian slopes of the Cordillera Oriental of southern Ecuadorian Andes. This new species constitutes the first record of the genus from Ecuador. Males and females of this new species were found in contact with the dorsal surfaces of head, body and extremities of male individuals of harlequin frogs, thus establishing the second record of species of the genus Sycorax feeding on frog blood.
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Griffith, Daniel M., Carlos Nivelo-Villavicencio, Fabián Rodas, Byron Puglla y Rodrigo Cisneros. "New altitudinal records of Panthera onca (Carnivora: Felidae) in the Andean region of Ecuador". Mammalia 86, n.º 2 (15 de diciembre de 2021): 190–95. http://dx.doi.org/10.1515/mammalia-2021-0136.
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Abstract We report two records of jaguars (Panthera onca) registered with camera traps at 2300 and 2660 m a.s.l. in the Ecuadorian Andes, which represent the first verifiable records of the species above 2000 m in Ecuador. As the first records of jaguars from Río Negro-Sopladora National Park and Tapichalaca Reserve, these records raise important questions about the species’ ecology and conservation in Andean montane forests. From a regional perspective, these records may indicate connectivity between jaguar populations inhabiting both sides of the Andes. Sustained monitoring of wildlife populations is necessary to discern the significance of these records and help develop strategies to ensure the conservation of this highly mobile species across the increasingly fragmented Andean-Amazonian landscapes of southern Ecuador.
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Wagner, S., I. Fast y F. Kaspar. "Climatic changes between 20th century and pre-industrial times over South America in regional model simulations". Climate of the Past Discussions 7, n.º 5 (22 de septiembre de 2011): 2981–3022. http://dx.doi.org/10.5194/cpd-7-2981-2011.
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Abstract. Two simulations with a regional climate model are analyzed for climatic changes between the late 20th century and a pre-industrial period over central and southern South America. The model simulations have been forced with large-scale boundary data from the global simulation performed with a coupled atmosphere-ocean general circulation model. The regional simulations have been carried out on a 0.44° × 0.44° grid (approx. 50 km × 50 km horizontal resolution). The differences in the external forcings are related to a changed greenhouse gas content of the atmosphere, being higher in the present-day simulation. For validation purposes the climate model is analyzed using a five year long simulation between 1993 and 1997 forced with re-analysis data. The climate model reproduces the main climatic features reasonably well, especially when comparing model output co-located with observational station data. However, the comparison between observed and simulated climate is hampered by the sparse meteorological station network in South America. The present-day simulation is compared with the pre-industrial simulation for atmospheric fields of near-surface temperatures, precipitation, sea level pressure and zonal wind. Higher temperatures in the present-day simulation are evident over entire South America, mostly pronounced over the southern region of the Andes Mountains and the Parana basin. During southern winter the higher temperatures prevail over the entire continent, with largest differences over the central Andes Mountains and the Amazonian basin. Precipitation differences show a more heterogeneous pattern, especially over tropical regions. This might be explained by changes in convective processes acting on small scales. During southern summer wetter conditions are evident over the Amazonian and Parana basin in the present-day simulation. Precipitation increases are evident over Patagonia together with decreases to the north along the western slope of the Andes Mountains. During southern winter also a dipole pattern along the Andes Mountains with wetter conditions over the southern parts and drier conditions over the central parts is evident. An interesting feature relates to precipitation changes with changing sign within a few 10th of kilometers along the southern parts of the Andes mountain chain. This pattern can be explained by changes in large-scale circulation related to latitudinal changes of the extratropical southern hemispheric westerlies.
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MENIN, MARCELO, ALBERTINA P. LIMA y DOMINGOS J. RODRIGUES. "The Tadpole of Vitreorana oyampiensis (Anura, Centrolenidae) in Central Amazonia, Brazil". Zootaxa 2203, n.º 1 (19 de agosto de 2009): 65–68. http://dx.doi.org/10.11646/zootaxa.2203.1.6.
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The family Centrolenidae contains about 148 species (Frost 2009), 11 genera and two subfamilies, distributed from southern Mexico to Panama, through the Andes from Venezuela to Bolivia, with species in the Amazon and Orinoco river basins, the Guiana Shield region, and the Atlantic forests of southeastern Brazil and northeastern Argentina (Guayasamin et al. 2009). The subfamily Centroleninae contains nine genera (Centrolene, Chimerella, Cochranella, Espadarana, Nymphargus, Rulyrana, Sachatamia, Teratohyla, and Vitreorana; Guayasamin et al. 2009). In spite of the high diversity in this subfamily, only the larvae of 15 species are well known (Centrolene altitudinale, C. daidaleum, C. geckoideum, C. hesperium, C. venezuelense, Cochranella granulosa, Espadarana andinum, E. prosoblepon, Teratohyla midas, T. pulverata, T. spinosa, Vitreorana castroviejoi, V. eurygnatha, V. helenae, and V. uranoscopa - Starret 1960; Duellman 1978; Heyer 1985; Cadle & McDiarmid 1990; Mijares-Urrutia 1990; Rada de Matinez 1990; Rueda-Almonacid 1994; Hoffmann 2004; Señaris & Ayarzagüena 2005; Rada et al. 2007). Thirteen of them are associated with Amazonian forests or forested slopes of the Andes (Frost 2009). The tadpole of Vitreorana oyampiensis (=Cochranella oyampiensis) has not been formally described; it was mentioned briefly (diagrammatic drawings and larval color notes) in Hero´s tadpole identification key from Central Amazonia (Hero 1990). In this paper we describe the tadpoles of V. oyampiensis and also provide comments on the spawning sites, clutch size, breeding periods and development site of tadpoles.
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Dorbath, C., L. Dorbath, A. Cisternas, J. Deverchere, M. Diament, L. Ocola y M. Morales. "On crustal seismicity of the Amazonian foothill of the central Peruvian Andes". Geophysical Research Letters 13, n.º 10 (octubre de 1986): 1023–26. http://dx.doi.org/10.1029/gl013i010p01023.
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Emlen, Nicholas Q. "Public discourse and community formation in a trilingual Matsigenka-Quechua-Spanish frontier community of Southern Peru". Language in Society 44, n.º 5 (15 de octubre de 2015): 679–703. http://dx.doi.org/10.1017/s0047404515000597.
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AbstractUntil recently, the members of a community on the Andean-Amazonian agricultural frontier of Southern Peru have tended to limit their social ties to members of their own families. But the residents have begun to forge a ‘community’ through a semiotic distinction between private and public spaces, social practices, and domains of morality. Particular discursive phenomena in the asamblea ‘community meeting’ are deployed to create and maintain the community as a domain of action distinct from kin commitments, and participation in the asamblea offers a context in which to assume a novel political and moral subjectivity. Thus, the social organizational construct of the community is emergent in public interactions. The article concludes with a comparative analysis of public discourse in another comunidad nativa ‘indigenous community’ that has not embraced the notion of ‘community’, and demonstrates how code-switching allows leaders there to invoke both the private and public modes of social authority. (Amazonia, Andes, Matsigenka, Spanish, Quechua)*
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GREENE, SHANE. "Getting over the Andes: The Geo-Eco-Politics of Indigenous Movements in Peru's Twenty-First Century Inca Empire". Journal of Latin American Studies 38, n.º 2 (27 de abril de 2006): 327–54. http://dx.doi.org/10.1017/s0022216x06000733.
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This article examines how President Alejandro Toledo's self-professed Andean identity and efforts to establish a state-led indigenous rights framework conflicted with a growing eco-ethno alliance of Andean and Amazonian representatives in Peru. Existing scholarly accounts declare the indigenous movement to be unimportant or, indeed, entirely absent in Peru. Yet, they do so by emphasising the centrality of the historical dynamic between the Andean region, where until recently local peoples have desisted from making explicit indigenous claims, and the urbanised coastal region, where the elite's power is most clearly concentrated. This obscures the Amazon as a site of historical events and eco-ethno-politics of national and global scope. The recent emergence of a debate on indigenous issues shows that the Amazonians' longer engagement in the global sphere of indigenous and environmental politics now places them in the position of exemplifying indigeneity for the Andeans and Peruvians at large. This shift challenges in fundamental ways the historical image of Peru the nation as inextricably implicated in the post-colonial fantasies of what I term the ‘Inca slot’.
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PADIAL, JOSÉ M., ROY McDIARMID y IGNA DE LA RIVA. "Distribution and morphological variation of Eleutherodactylus mercedesae Lynch & McDiarmid, 1987 (Amphibia, Anura, Leptodactylidae) with first record for Peru". Zootaxa 1278, n.º 1 (3 de agosto de 2006): 49. http://dx.doi.org/10.11646/zootaxa.1278.1.2.
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We report new distributional information for Eleutherodactylus mercedesae in Bolivia, and provide the first record for Peru based on an adult female. This species, previously endemic to Bolivia, now ranges across about 1000 km in cloud forests on the Amazonian slopes of the Andes from southern Peru to central Bolivia. We provide the first morphological description of females based on two specimens, compare them with the male type and paratype, add some observations to the original description, and comment on variation in the species.
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Colinvaux, Paul A., Mark B. Bush, Miriam Steinitz-Kannan y Michael C. Miller. "Glacial and Postglacial Pollen Records from the Ecuadorian Andes and Amazon". Quaternary Research 48, n.º 1 (julio de 1997): 69–78. http://dx.doi.org/10.1006/qres.1997.1908.
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A long pollen record is derived from sediments of a lake dammed behind a low moraine of the last glaciation at 3°S latitude in the Ecuadorian Andes and is compared with a glacial age pollen record from the Amazon rainforest immediately below. Lake Surucucho (Llaviucu) lies at 3180 m on the Amazonian flank of the Andes and above the glacial age pollen record from San Juan Bosco at 970 m. The Surucucho pollen record is interpreted as showing treeless vegetation in glacial times, advance of treeline in late-glacial time, and Holocene development of modern Andean forests. Combining the Surucucho and San Juan Bosco records shows that Andean vegetation was affected by glacial cooling at all elevations. Vegetation did not move up and down slope as belts. Rather, plant associations were reformed as temperature-sensitive species found different centers of distribution with changing temperature.
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Morales-Martínez, Darwin M., Héctor E. Ramírez-Chaves, Javier E. Colmenares-Pinzón y Luis G. Gómez. "The Koepcke’s spear-nosed bat, Gardnerycteris koepckeae (Gardner and Patton, 1972) (Chiroptera: Phyllostomidae), is not endemic to Peru: first record from the Amazon foothills of Colombia". Mammalia 84, n.º 5 (25 de septiembre de 2020): 439–47. http://dx.doi.org/10.1515/mammalia-2019-0107.
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AbstractWe report the first record of the rare Koepcke’s spear-nosed bat Gardnerycteris koepckeae collected outside of Peru, based on morphological and cytochrome b data. The species was found at the National Natural Park Alto Fragua Indi-Wasi, Department of Caquetá, Colombia. This record extended the species distribution 1400 km north from the northernmost known locality in Huanhuachayo, Ayacucho, Peru. This finding suggests that G. koepckeae is distributed over middle elevations along the eastern slope of the Andean-Amazonia foothills in Peru and Colombia, similar to other Phyllostomid bats, such as Vampyressa melissa and Lonchophylla handleyi. We reviewed the threatened category of G. koepckeae, currently categorized as Data Deficient (DD), according to the International Union for Conservation of Nature (IUCN), but considered as Endangered (EN) in recent papers. Based on this new record, we suggest that the species should be included in future assessments as Near Threatened (NT) or Vulnerable (VU) based on its wider distribution along the Andean-Amazonian foothills of Colombia, Ecuador and Peru, and probably the Orinoco slope of the Andes of Colombia and Venezuela.
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STONIS, JONAS R. y ANDRIUS REMEIKIS. "Odd species of Nepticulidae (Lepidoptera) from the American rainforest and southern Andes". Zootaxa 4392, n.º 3 (11 de marzo de 2018): 458. http://dx.doi.org/10.11646/zootaxa.4392.3.2.
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In addition to numerous new species that can be placed to genera, our recent study of a large collection sample of Nepticulidae (Lepidoptera) from Central and South America revealed a few odd-looking new species, the taxonomic position of which seems rather problematic and, therefore, preliminary. Here we describe three new species of pygmy moths (Nepticulidae) from the Amazonian rainforest (Venezuela) and southern Andes (Chile and Argentina) possessing uncommon morphology. We also provide the first photographic documentation of the Central American Acalyptris argentosa (Puplesis & Robinson, 2000) with rather odd and hitherto unknown hindwing scaling. All species treated in the paper are extensively illustrated with drawings and (or) photographs of the adults and genitalia.
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Belfort, Edgard y Javier González. "Psychiatry in Venezuela". International Psychiatry 2, n.º 9 (julio de 2005): 11–13. http://dx.doi.org/10.1192/s1749367600007335.
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The Bolivarian Republic of Venezuela covers 916 445 km2; to the north is the Caribbean Sea, to the south-east the Amazonian region and the plains of Brazil and Colombia, and to the west the Andes and the Colombian Guajira peninsula. Its estimated population (2004) is 25 226 million, which is concentrated along the north coastal area, where the population density exceeds 200 inhabitants per km2; most of the territory remains almost inhabited (fewer than 6 inhabitants per km2), in particular the border areas. The population is mainly urban: 70% live in cities with more than 50 000 inhabitants.
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Duellman, William E. "The last one: A new species of Osteocephalus (Anura: Hylidae) from Colombia, with comments on the morphological and behavioral diversity within the genus". Phyllomedusa: Journal of Herpetology 18, n.º 2 (17 de diciembre de 2019): 141–57. http://dx.doi.org/10.11606/issn.2316-9079.v18i2p141-157.
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A new species of Osteocephalus (Anura: Hylidae) from Colombia, with comments on the morphological and behavioral diversity within the genus. A striking, undescribed species of Osteocephalus from the Amazonian slopes of the Andes in Departamento de Putumayo in southern Colombia is a member of the Osteocephalus buckleyi Group. Aside from minor morphological characters, the new species differs from all other members of the group by having a golden yellow iris with a median horizontal black stripe. The diversity in morphological and reproductive behavior reveals various features that are phylogenetically signifcant, but several species remain to be described.
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Mendoza, Benito, Nelly Guananga, Jesus R. Melendez y Daniel A. Lowy. "Differences in total iron content at various altitudes of Amazonian Andes soil in Ecuador". F1000Research 9 (20 de febrero de 2020): 128. http://dx.doi.org/10.12688/f1000research.22411.1.
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Although iron is not contained by chlorophyll, it is indispensable for plants as it plays an essential role in the biosynthesis of chlorophyll. It is a component of many important plant enzyme systems, e.g. cytochrome oxidase, which is responsible for electron transport. Therefore, examining iron content of soils, particularly ionic forms of iron (Fe2+ and Fe3+) is important for fruit growers. In this article, we disclose the total iron content determined in soils (Hyperalic Alisol soil) at three altitudes of Amazonian rainforest in Ecuador. We examine how different altitudes impact the pH and total iron content in the selected study area. We found that total iron content significantly decreases (R2=0.966) at lower altitudes. For future studies, the authors recommend that along with Fe ion content one should determine calcium, microbial biomass, and microbial activity to better understand iron mobility and dynamics of iron uptake in the area.
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Bush, Mark B. "New and Repeating Tipping Points: The Interplay of Fire, Climate Change, and Deforestation in Neotropical Ecosystems". Annals of the Missouri Botanical Garden 105, n.º 3 (23 de septiembre de 2020): 393–404. http://dx.doi.org/10.3417/2020565.
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A 370,000-year paleoecological history of fire spanning four glacial cycles provides evidence of plant migration in response to Andean climate change. Charcoal, an indicator of fire, is only occasionally observed in this record, whereas it is ubiquitous in Holocene-aged Andean records. Fire is a transformative agent in Amazonian and Andean vegetation but is shown to be rare in nature. As humans promote fire, fire-free areas become microrefugia for fire-sensitive species. A distinction is drawn between microrefugia resulting from fire-free zones and those caused by unusual climatic conditions. The importance of this distinction lies in the lack of warmer-than-modern microrefugia aiding upslope migration in response to warming, whereas fire-free microrefugia support tree species above modern tree line or in areas of Amazonia least used by humans. The synergy between fire, deforestation, and climate change could promote a state-change in the ecosystem, one where new microrefugia would be needed to maintain biodiversity. Past tipping points are identified to have occurred within ca. 1°C–1.5°C of modern conditions. The recent climatic instability in both Amazonia and the Andes is viewed in the context of ecological flickering, while the drought-induced and fire-induced tree mortality are aspects of critical slowing down; both possibly portending an imminent tipping point.
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Köhler, Jörn, Frank Glaw, César Aguilar-Puntriano, Santiago Castroviejo-Fisher, Juan C. Chaparro, Ignacio De la Riva, Giussepe Gagliardi-Urrutia, Roberto Gutiérrez, Miguel Vences y José M. Padial. "Similar looking sisters: A new sibling species in the Pristimantis danae group from the southwestern Amazon basin (Anura, Strabomantidae)". Zoosystematics and Evolution 100, n.º 2 (16 de mayo de 2024): 565–82. http://dx.doi.org/10.3897/zse.100.119143.
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We describe a new frog species that is the sibling of Pristimantis reichlei. These two sister species inhabit the Amazonian lowlands and adjacent foothills of the Andes, from central Bolivia to central Peru. Pristimantis reichlei occurs from central Bolivia to southern Peru (Alto Purús National Park), while the new species occurs from northern Bolivia (Departamento Pando) to Panguana in central Peru (Departamento Huánuco), at elevations between 220 and 470 m a.s.l. In spite of their morphological crypsis, these siblings occur in syntopy without evidence of interbreeding (in the Alto Purús area) and are recovered as reciprocally monophyletic. Their uncorrected pairwise genetic distances in the 16S rRNA gene range from 9.5–13.5%, and their advertisement calls differ in both qualitative and quantitative traits. Moreover, our study found uncorrected pairwise distances within the new species of up to 5.0% and up to 9.3% within P. reichlei. We therefore cannot rule out the possible existence of hybrids or additional species-level lineages hidden in this complex. Furthermore, we found another potential pair of sibling species composed of P. danae and an unnamed lineage, with divergences of 9.4% in the 16S gene, whose in-depth analysis and taxonomic treatment are pending future revision. With the new nominal species, the Pristimantis danae species group now includes 20 species, distributed across the upper Amazon basin and in the eastern Andes, from western Brazil to Bolivia and Peru. Our study, together with an increasing number of other studies, indicates that sibling species are far from being rare among Amazonian amphibians and that species resolution remains low even for groups that have received considerable attention in recent years.
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Moyano Nieto, Ismael Enrique, Renato Cordani, Lorena Paola Cárdenas Espinosa, Norma Marcela Lara Martínez, Oscar Eduardo Rojas Sarmiento, Manuel Fernando Puentes Torres, Diana Lorena Ospina Montes, Andrés Felipe Salamanca Saavedra y Gloria Prieto Rincón. "Interpretation of geophysical anomalies for mineral resource potential evaluation in Colombia: Examples from the northern Andes and Amazonian regions". Boletín Geológico, n.º 46 (30 de junio de 2020): 5–22. http://dx.doi.org/10.32685/0120-1425/boletingeo.46.2020.514.
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This paper focuses on presentation of the methodology used by geophysicists at the Servicio Geológico Colombiano (SGC) for the processing, anomaly selection and interpretation of airborne magnetometry and gamma spectrometry data. Three (3) selected magnetic anomalies from different geological settings (Andes Cordillera, San Lucas Range and Amazon region) are presented as examples. 3D magnetic vector inversion (MVI) modeling of each of the selected magnetic anomalies shows magnetic sources less than 100 m deep or exposed with sizes from 2.5 to 6 km. The magnetic data interpretation also allows the identification of linear features that could represent structural control for fluid migration and/or ore emplacement. Additionally, the integration of the geophysical data with other geoscientific information (geologic, metallogenic and geochemical data) leads to the proposition of an exploration model for each anomaly: intrusion-related/VMS deposits for the Andes, porphyry/intrusion-related/epithermal deposits for San Lucas and carbonatite/kimberlite for Amazonas. The methodology used and examples presented illustrate the potential of SGC airborne geophysical data for mineral resource evaluation and as input for the design of fieldwork for geological, geophysical, geochemical and metallogenic characterization of an area of interest.
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Borja, M. O., R. Camargo, N. Moreno, E. Turpo y S. Villacis. "A LONG-TERM LAND COVER AND LAND USE MAPPING METHODOLOGY FOR THE ANDEAN AMAZON". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W12-2020 (6 de noviembre de 2020): 373–78. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w12-2020-373-2020.
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Abstract. The data developed by the MapBiomas Amazon initiative ( http://amazonia.mapbiomas.org/ ) led by the Amazon Geo-referenced Socio-environmental Information Network’s (RAISG) is of unprecedented spatial and temporal resolution for the Andes region. It’s comprised by a series of annual maps for the years 2000 to 2017 that allow to monitor the extent of transformation in this region using a single regional methodological approach. Several variables were included to solve Andes-specific methodological challenges and they represent adaptations of RAISG’s Amazonian methodology to the Andean region. Among such, is the use of the novel NDFIb index (Turpo, 2018), an adaptation of the NDFI index that aims at mapping Andean Wetlands. Glaciers identification was aided by the fractional abundance of snow (Turpo, 2018), as well as small water bodies identification with McFeeters (1996) NDWI water index. This experience unfolds promising accessibility to novel land cover and land use regional reconstructions and comparisons possible only by the use of large-scale cloud-computing data processing tools, open source technology, spatially and temporally comprehensive remote sensing data, along with RAISG’s standardized protocols and frameworks.
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De la Riva, Ignacio, Juan C. Chaparro, Santiago Castroviejo-Fisher y José M. Padial. "Underestimated anuran radiations in the high Andes: five new species and a new genus of Holoadeninae, and their phylogenetic relationships (Anura: Craugastoridae)". Zoological Journal of the Linnean Society 182, n.º 1 (28 de julio de 2017): 129–72. http://dx.doi.org/10.1093/zoolinnean/zlx020.
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AbstractDespite recent efforts to accelerate exploration and species description, the diversity of high Andean frogs remains highly underestimated. We report high levels of species diversity in direct-developing frogs or terraranas inhabiting the wet puna and adjacent cloud forests of the Amazonian versant of the Andes in Bolivia and Peru. Descriptive evidence of external morphology, distribution patterns and molecular phylogenetic analyses support the existence of nine unnamed species in two clades, which represents a 30% increase in species diversity for those clades. The relationships of these species and their relatives in Holoadeninae are tested using nuclear and mitochondrial genes for 159 terminals representing the 11 genera in this subfamily and 25 species of previously unknown relationships. Our results corroborate species monophyly in all but three cases and support the monophyly of all Holoadeninae genera, albeit the position of some differs between analyses. We propose a new genus (Microkayla gen. nov.) for the clade containing all Bolivian species formerly in Psychrophrynella plus five species from southern Peru. The new genus is monophyletic and supported by anatomical synapomorphies. Psychrophrynella is re-diagnosed and redefined to include three species from the Andes of southern Peru. We discuss the taxonomic instability associated with Noblella and Psychrophrynella due to the fact that the type species of both genera share a number of traits that support a close relationship. We also name and describe three new species of Bryophryne and two of Microkayla from Peru, provide baseline data for the future description of four Bolivian species of Microkayla, and describe the unknown mating calls of two species. Our results support that the grasslands of the Amazonian versant of the Andes harbour a large diversity of species with small altitudinal and horizontal distributions that replace each other along a latitudinal axis. These species belong to different lineages whose closest relatives are forest species, often from distant parts of the continent. These patterns suggest that high Andean environments were colonized several times independently by species with forest ancestors and which radiated into a multitude of species with remarkably similar ecomorphologies. The extent of these radiations remains obscured by a still rudimentary knowledge of species diversity due to insufficient fieldwork and taxonomic research.
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Torres-Carvajal, Omar, Claudia Koch, Jorge H. Valencia, Pablo J. Venegas y Lourdes Y. Echevarría. "Morphology and distribution of the South American snake Chironius leucometapus (Serpentes: Colubridae)". Phyllomedusa: Journal of Herpetology 18, n.º 2 (17 de diciembre de 2019): 241–54. http://dx.doi.org/10.11606/issn.2316-9079.v18i2p241-254.
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Morphology and distribution of the South American snake Chironius leucometapus (Serpentes: Colubridae). Chironius leucometapus was described more than 25 years ago as subspecies of C. fuscus from restricted area in the Department of Junín in central Peru, with no additional specimens reported since. Examination of 17 new specimens reveals that C. leucometapus is widespread along the Amazonian slopes of the Andes between central Peru and northern Ecuador. New morphological data including scalation, hemipenes, color in life, and the frst description of the skull of Chironius to be based on high-quality CT-scan images are presented. The number of species of Chironius from Ecuador is elevated to eight.
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Carvalho Francisco, Jessica Nayara y Lúcia G. Lohmann. "Phylogeny and Biogeography of the Amazonian Pachyptera (Bignonieae, Bignoniaceae)". Systematic Botany 45, n.º 2 (13 de junio de 2020): 361–74. http://dx.doi.org/10.1600/036364420x15862837791230.
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Abstract—The Amazon houses a large proportion of the overall biodiversity currently found on Earth. Despite that, our knowledge of Amazonian biodiversity is still limited. In this study, we reconstruct the phylogeny of Pachyptera (Bignoniaceae), a genus of neotropical lianas that is centered in the Amazon. We then use this phylogenetic framework to re-evaluate species limits and study the biogeographic history of the genus. We sampled three molecular markers (i.e. ndhF, rpl32-trnL, and PepC) and 51 individuals representing the breadth of morphological variation and geographic distribution of all species recognized in the genus. We used this information to reconstruct phylogenetic relationships among individuals of Pachyptera using Bayesian and maximum likelihood approaches. The resulting molecular phylogeny was used as a basis to test species limits within the P. kerere species complex using a cpDNA coalescent approach (GMYC). GMYC identified five potential species within the P. kerere species complex that were subsequently evaluated in the light of morphology. Morphological data supported the recognition of four of the five potential species suggested by GMYC, all of which were also supported by a multispecies coalescent model in a Bayesian framework. The phylogeny of Pachyptera was time-calibrated and used to reconstruct the biogeographical history of the genus. We identified historically important migration pathways using our comprehensive cpDNA dataset and a Bayesian stochastic search variable selection (BSSVS) framework. Our results indicate that the genus originated in lowland Amazonia during the Middle Eocene, and subsequently occupied Central America and the Andes. Most of the diversification of Pachyptera occurred in the Miocene, a period of intense perturbations in South America.
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Lopes Moreira, Giselle, Jose L. Panero, Peter Inglis W., Daniela Zappi C. y Taciana Cavalcanti, B. "A TIME-CALIBRATED PHYLOGENY OF VERBESINA (HELIANTHEAE – ASTERACEAE) BASED ON NUCLEAR RIBOSOMAL ITS AND ETS SEQUENCES". Edinburgh Journal of Botany 80 (24 de noviembre de 2023): 1–22. http://dx.doi.org/10.24823/ejb.2023.1953.
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Verbesina L. is a genus of the tribe Heliantheae, subtribe Verbesininae (Asteraceae), with distribution in the Americas, where Mexico and the Andes harbour the richest concentration of species. The approximately 325 species in the genus are shrubs, subshrubs, trees and rarely herbs. Despite its high species diversity and biogeographical importance, the only available phylogenetic hypothesis for Verbesina was based on chloroplast DNA restriction site data. In the present study, nuclear ITS and ETS DNA sequence data were used with an expanded taxon sampling, particularly among the South American Verbesina species, to improve phylogenetic resolution and support, clarify infrageneric relationships, and resolve biogeographical questions in the genus. The results of our new analysis corroborate the monophyly of Verbesina, but its current classification into 12 taxonomic sections, based on morphological characters such as phyllotaxis, head size, corolla colour, and presence of ray flowers, is not congruent with the molecular phylogeny, in which most sections are polyphyletic. We also show that Verbesina diverged in the late Miocene of North America, about 8 Ma. At least two independent Pleistocene dispersals into South America across the Isthmus of Panama and along the Southern Andes are evident, beginning around 3.23 Ma (1.27–3.23 Ma) in the Middle Pliocene, and resulting in an extra-Amazonian distribution of the genus inSouth America. Diversification in South America began around 2.83 Ma with occupation of the Andes. Colonisation of Brazil is estimated to have occurred around 2.15 Ma, from Andean lineages.
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Espitia Fajardo, Marisol, Nelson Rivera Franco, Yamid Braga y Guillermo Barreto. "New Y-SNPs in QM3 indigenous populations of Colombia". PLOS ONE 18, n.º 12 (6 de diciembre de 2023): e0294516. http://dx.doi.org/10.1371/journal.pone.0294516.
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In evolutionary studies of human populations based on the Y chromosome, the majority of Native Americans belong to the QM3 lineage. Therefore, to study the history of groups inhabiting northern South America, it is necessary to have a higher resolution of the tree. The objective of this work was to identify new SNPs of the QM3 lineage that would allow the evaluation of the phylogenetic relationships between Andean and Amazonian populations of Colombia. Sequences previously obtained from two Y chromosomes of Amazonian populations were used, from which 13 potential SNPs were selected and typed in 171 Amazonian samples from the Vaupés region and in 60 samples from the Pasto, Nasa, Embera, Arhuaco and Kogüi ethnic groups of the Andean region. In addition, the main SNPs/markers (L56, L54, M346, M848, Z780, CTS11780) defining autochthonous Q lineages were typed, along with others defined by different SNPs/markers as reported in the literature (CTS11357, SA05, Z19319, Z5915, and Z19384). It was found that all the new SNPs are present in the Amazonian samples and only 2 of them are shared with the Embera, Nasa and Pasto, but none with the Kogüi and Arhuaco from the northern Andes, in the Colombian Caribbean. Combining the 13 variants of the present study with 14 previously reported and using TMRCA, a new QM3 tree proposal is generated. This method makes it possible to increase the number of sublineages of QM3 with a higher resolution and to detect differences between the different populations of Vaupés in the Amazon, as in the case of the Kubeos and Pisamiras, the latter of which is in grave danger of extinction. These new sublineages are useful for microevolutionary studies of the Amerindian populations of South America.
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PADIAL, JOSÉ M., JUAN C. CHAPARRO, JÖRN KÖHLER y IGNACIO DE LA RIVA. "Rediscovery, resurrection and redescription of Rhinella leptoscelis (Boulenger, 1912) (Anura: Bufonidae)". Zootaxa 2115, n.º 1 (22 de mayo de 2009): 56–64. http://dx.doi.org/10.11646/zootaxa.2115.1.5.
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We resurrect Rhinella leptoscelis (Anura: Bufonidae) from the synonymy of R. veraguensis and redescribe it on the basis of the holotype, and recently collected specimens from Peru and Bolivia. Rhinella leptoscelis is well distinguished from all other species of the R. veraguensis group by its flat head with well developed orbitotympanic and postorbital crests, distinct tympanum, large parotoid glands, spiny tubercles on dorsal surfaces, long and slender extremities, dorsolateral row of conical, enlarged and elevated tubercles, webbing absent on fingers, basal and serrated webbing between toes, and first finger longer than second. This species is known from the humid forests of the Amazonian versant of the Andes from central Bolivia to southern Peru.
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Villota, Johana, Héctor E. Ramírez-Chaves y Thomas R. Defler. "Plecturocebus caquetensis (Primates: Pitheciidae)". Mammalian Species 53, n.º 1002 (24 de abril de 2021): 35–42. http://dx.doi.org/10.1093/mspecies/seab004.
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Abstract Plecturocebus caquetensis (Defler, Bueno, and García, 2010) is a Neotropical primate commonly called the Caquetá titi monkey. It is small-sized with long, soft pelage of mixed coloration including grayish and buffy brown to agouti tones. It lacks the blackish or whitish band that is present on the forehead of closely related species. The tail is agouti-colored and slightly banded at its base. Endemic to the Amazonian region of Colombia with a distribution in areas near the eastern slopes of the Eastern and Central Cordillera of the Andes, P. caquetensis is confirmed in 104 localities in the departments of Cauca and Caquetá in Colombia. P. caquetensis is considered “Critically Endangered” (CR) by the International Union for Conservation of Nature and Natural Resources.
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Henriques-Oliveira, Ana Lucia, Márcia Regina Spies y Leandro Lourenço Dumas. "A new species of Notalina Mosely, 1936 (Trichoptera: Leptoceridae) from Southeastern". Biota Neotropica 12, n.º 4 (diciembre de 2012): 130–34. http://dx.doi.org/10.1590/s1676-06032012000400014.
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The Neotropical subgenus Notalina (Neonotalina) Holzenthal, 1986 has ten described species in two species groups: brasiliana, formed by seven species from Southeastern Brazilian and Goiás State; and roraima, represented by three species from the Amazonian and Andes regions. In this paper, a new species of Notalina is described and illustrated from specimens collected in the Mantiqueira mountain range, Southeastern Brazil. The new species belongs to the brasiliana group and is easily recognized by the poorly developed dorsomesal and ventrolateral processes and the pair of mound-like protuberances located mesolaterally on abdominal segment X, and by the robust, rounded mesoventral processes and long digitate mesodorsal processes of the inferior appendages. A key to the Neotropical species in the genus is provided.
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JUNGFER, KARL-HEINZ. "The taxonomic status of some spiny-backed treefrogs, genus Osteocephalus (Amphibia: Anura: Hylidae)". Zootaxa 2407, n.º 1 (23 de marzo de 2010): 28. http://dx.doi.org/10.11646/zootaxa.2407.1.2.
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A reassessment of some Amazonian spiny-backed treefrogs (Osteocephalus) either considered to be junior synonyms or not associated yet with Osteocephalus reveals that O. cabrerai (Cochran and Goin, 1970) from lowland Colombia and Peru is distinct from a frog previously used to revalidate the species, that O. festae (Peracca, 1904) is a valid species from the foothills of the Andes in Ecuador, and that Hyla inframaculata Boulenger, 1882, from the lower Amazon in Brazil, is a member of this genus. The oldest available name for O. elkejungingerae (Henle, 1981) from the Andean foothills in Peru is O. mimeticus (Melin, 1941). Another Melin (1941) species, Hyla vilarsi from the Rio Negro watershed in Brazil, is also an Osteocephalus revalidated from the synonymies of several other frogs.
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Capriles, José M., Calogero M. Santoro, Richard J. George, Eliana Flores Bedregal, Douglas J. Kennett, Logan Kistler y Francisco Rothhammer. "Pre-Columbian transregional captive rearing of Amazonian parrots in the Atacama Desert". Proceedings of the National Academy of Sciences 118, n.º 15 (29 de marzo de 2021): e2020020118. http://dx.doi.org/10.1073/pnas.2020020118.
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The feathers of tropical birds were one of the most significant symbols of economic, social, and sacred status in the pre-Columbian Americas. In the Andes, finely produced clothing and textiles containing multicolored feathers of tropical parrots materialized power, prestige, and distinction and were particularly prized by political and religious elites. Here we report 27 complete or partial remains of macaws and amazon parrots from five archaeological sites in the Atacama Desert of northern Chile to improve our understanding of their taxonomic identity, chronology, cultural context, and mechanisms of acquisition. We conducted a multiproxy archaeometric study that included zooarchaeological analysis, isotopic dietary reconstruction, accelerated mass spectrometry radiocarbon dating, and paleogenomic analysis. The results reveal that during the Late Intermediate Period (1100 to 1450 CE), Atacama oasis communities acquired scarlet macaws (Ara macao) and at least five additional translocated parrot species through vast exchange networks that extended more than 500 km toward the eastern Amazonian tropics. Carbon and nitrogen stable isotopes indicate that Atacama aviculturalists sustained these birds on diets rich in marine bird guano-fertilized maize-based foods. The captive rearing of these colorful, exotic, and charismatic birds served to unambiguously signal relational wealth in a context of emergent intercommunity competition.
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Guevara, Evelyn K., Jukka U. Palo, Sanni Översti, Jonathan L. King, Maria Seidel, Monika Stoljarova, Frank R. Wendt et al. "Genetic assessment reveals no population substructure and divergent regional and sex-specific histories in the Chachapoyas from northeast Peru". PLOS ONE 15, n.º 12 (31 de diciembre de 2020): e0244497. http://dx.doi.org/10.1371/journal.pone.0244497.
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Many native populations in South America have been severely impacted by two relatively recent historical events, the Inca and the Spanish conquest. However decisive these disruptive events may have been, the populations and their gene pools have been shaped markedly also by the history prior to the conquests. This study focuses mainly on the Chachapoya peoples that inhabit the montane forests on the eastern slopes of the northern Peruvian Andes, but also includes three distinct neighboring populations (the Jívaro, the Huancas and the Cajamarca). By assessing mitochondrial, Y-chromosomal and autosomal diversity in the region, we explore questions that have emerged from archaeological and historical studies of the regional culture (s). These studies have shown, among others, that Chachapoyas was a crossroads for Coast-Andes-Amazon interactions since very early times. In this study, we examine the following questions: 1) was there pre-Hispanic genetic population substructure in the Chachapoyas sample? 2) did the Spanish conquest cause a more severe population decline on Chachapoyan males than on females? 3) can we detect different patterns of European gene flow in the Chachapoyas region? and, 4) did the demographic history in the Chachapoyas resemble the one from the Andean area? Despite cultural differences within the Chachapoyas region as shown by archaeological and ethnohistorical research, genetic markers show no significant evidence for past or current population substructure, although an Amazonian gene flow dynamic in the northern part of this territory is suggested. The data also indicates a bottleneck c. 25 generations ago that was more severe among males than females, as well as divergent population histories for populations in the Andean and Amazonian regions. In line with previous studies, we observe high genetic diversity in the Chachapoyas, despite the documented dramatic population declines. The diverse topography and great biodiversity of the northeastern Peruvian montane forests are potential contributing agents in shaping and maintaining the high genetic diversity in the Chachapoyas region.
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Arraut, Josefina Moraes y Prakki Satyamurty. "Precipitation and Water Vapor Transport in the Southern Hemisphere with Emphasis on the South American Region". Journal of Applied Meteorology and Climatology 48, n.º 9 (1 de septiembre de 2009): 1902–12. http://dx.doi.org/10.1175/2009jamc2030.1.
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Abstract December–March climatologies of precipitation and vertically integrated water vapor transport were analyzed and compared to find the main paths by which moisture is fed to high-rainfall regions in the Southern Hemisphere in this season. The southern tropics (20°S–0°) exhibit high rainfall and receive ample moisture from the northern trades, except in the eastern Pacific and the Atlantic Oceans. This interhemispheric flow is particularly important for Amazonian rainfall, establishing the North Atlantic as the main source of moisture for the forest during its main rainy season. In the subtropics the rainfall distribution is very heterogeneous. The meridional average of precipitation between 35° and 25°S is well modulated by the meridional water vapor transport through the 25°S latitude circle, being greater where this transport is from the north and smaller where it is from the south. In South America, to the east of the Andes, the moisture that fuels precipitation between 20° and 30°S comes from both the tropical South and North Atlantic Oceans whereas between 30° and 40°S it comes mostly from the North Atlantic after passing over the Amazonian rain forest. The meridional transport (across 25°S) curve exhibits a double peak over South America and the adjacent Atlantic, which is closely reproduced in the mean rainfall curve. This corresponds to two local maxima in the two-dimensional field of meridional transport: the moisture corridor from Amazonia into the continental subtropics and the moisture flow coming from the southern tropical Atlantic into the subtropical portion of the South Atlantic convergence zone. These two narrow pathways of intense moisture flow could be suitably called “aerial rivers.” Their longitudinal positions are well defined. The yearly deviations from climatology for moisture flow and rainfall correlate well (0.75) for the continental peak but not for the oceanic peak (0.23). The structure of two maxima is produced by the effect of transients in the time scale of days.
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GUAYASAMIN, JUAN M. y W. CHRIS FUNK. "The amphibian community at Yanayacu Biological Station, Ecuador, with a comparison of vertical microhabitat use among Pristimantis species and the description of a new species of the Pristimantis myersi group". Zootaxa 2220, n.º 1 (4 de septiembre de 2009): 41–66. http://dx.doi.org/10.11646/zootaxa.2220.1.2.
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We provide information regarding the composition of the amphibian community at Yanayacu Biological Station, on the Amazonian slopes of the Andes of Ecuador, and describe a new species of Pristimantis that is referred to the P. myersi group. The new species is distinguished from other species of the group mainly by its color pattern, and by lacking ulnar and tarsal tubercles. The advertisement call of the new species has two distinct call types, a short call with 1–3 pulses and a long call with a mean of 15.5–18.9 more rapid pulses, which are often produced together in long call series. Finally, we analyze the microhabitat use of Pristimantis species found at Yanayacu and find that there is significant variation in vertical habitat use among Pristimantis, highlighting the ecological diversity of sympatric species.