Parana River Delta Research Articles

How are arthropod communities structured in a modified wetland under different productive activities?

Wetlands are among the most threatened ecosystems around the world due to changes in land use. Particularly, in the Lower Parana River Delta the main productive activities with economic impact in the region are planted forest and silvopastoral systems. To carry out these productive activities, natural hydrology of this wetland has been deeply modified and different management practices are implemented. Ground-dwelling arthropods are among the most sensitive taxa to environmental changes, so they are good bioindicators of the effect of these changes on biodiversity. In this context, we compare the structure and composition of ground-dwelling arthropod communities and their seasonal variations in the planted forest and silvopastoral systems of the Lower Parana River Delta, to characterize these land use associated with different management practices. We recorded a total of 73 families using pitfall traps (N = 1728). We observed that communities in intensive-managed planted forests were less rich and more evenness, while communities in less-managed planted forests were richer and less evenness. Also, we observed that warm seasons presented more arthropod family richness than cold seasons. The intensity of management practices, the presence of cattle and seasonality are factors that significantly decrease ground-dwelling arthropod richness. So, Silvopastoral systems negatively affect ground-dwelling arthropod communities compared to planted forest. A decrease in the intensity of management practices favors the understory growth, offering more resources for the arthropod families already established and facilitating the establishment of new ones. This increase in arthropod diversity promotes the presence of benefic species and the conservation of biodiversity in this modified wetland ecosystem.

Cover classifications in wetlands using Sentinel-1 data (Band C): a case study in the Parana river delta, Argentina

With the launch of the Sentinel-1 mission, for the first time, multitemporal and dual-polarization C-band SAR data with a short revisit time is freely available. How can we use this data to generate accurate vegetation cover maps on a local scale? Our main objective was to assess the use of multitemporal C-Band Sentinel-1 data to generate wetland vegetation maps. We considered a portion of the Lower Delta of the Paraná River wetland (Argentina). Seventy-four images were acquired and 90 datasets were created with them, each one addressing a combination of seasons (spring, autumn, winter, summer, complete set), polarization (VV, HV, both), and texture measures (included or not). For each dataset, a Random Forest classifier was trained. Then, the kappa index values (κ) obtained by the 90 classifications made were compared. Considering the datasets formed by the intensity values, for the winter dates the achieved kappa index values (κ) were higher than 0.8, while all summer datasets achieved κ up to 0.76. Including feature textures based on the GLCM showed improvements in the classifications: for the summer datasets, the κ improvements were between 9% and 22% and for winter datasets improvements were up to 15%. Our results suggest that for the analyzed context, winter is the most informative season. Moreover, for dates associated with high biomass, the textures provide complementary information.

SPECIFIC FEATURES OF WATER BALANCE AND DISTRIBUTION OF WATER RUNOFF AND NANOSE IN THE PARANA DELTA

The current values of the components of the water balance of the Parana Delta, one of the largest deltas of South America, as well as the results of calculations of the actual distribution and redistribution of water runoff and sediment yield in the delta branches are presented. The climatic features of the delta's water balance are revealed. Long-term changes in the water flow distribution in the delta branches are considered and estimates of the dynamics of delta estuarine line are given.

¿La combinación de clones posee alguna ventaja sobre los sistemas monoclonales?

Las plantaciones forestales han sido tradicionalmente desarrolladas a partir de material de propagación de origen seminal. Sin embargo, las principales especies plantadas en el mundo se pueden propagar vegetativamente, por lo que las posibilidades para el desarrollo de la silvicultura clonal son crecientes. El cultivo de Salicáceas se realiza con estacas o guías, por lo que las plantaciones son 100% producidas bajo un esquema de silvicultura clonal. Además, en el Delta del Río Paraná los rodales se instalan como bloques monoclonales y el clon Populus deltoides ‘Australiano 129/60’ es el más difundido, definiendo una matriz productiva con una estrecha diversidad genética. Esto determina que el sistema sea menos estable y trae aparejado un riesgo productivo ante la aparición de condiciones de estrés biótico o abiótico. En consecuencia, el modelo de silvicultura monoclonal presenta algunas desventajas no solo desde el punto de vista ecológico, sino también productivo. A partir de la posibilidad que brindan las especies forestales, que presentan una gran variabilidad tanto intra como interespecífica, es posible pensar en combinación de clones para aumentar la diversidad genética de las plantaciones. Las plantaciones clonales mixtas pueden favorecer a la disminución de los impactos de las actividades productivas en el ambiente, distribuir espacialmente la demanda de nutrientes del suelo, aumentar la diversidad genética y mejorar los índices de rendimiento del rodal. El objetivo de esta revisión es analizar los antecedentes de silvicultura clonal y plantaciones mixtas como base para la propuesta de alternativas silviculturales para las Salicáceas del Delta del Paraná.

El estrato orgánico de los humedales del delta del río Paraná (Buenos Aires, Argentina). Disputas en torno a su conceptualización y su valoración

El objetivo de este artículo es analizar las maneras en que técnicos, científicos y pobladores locales que interactúan en un área del delta del Paraná (Buenos Aires, Argentina) conceptualizan y valoran al estrato orgánico presente en los humedales de la región. A través de un enfoque etnográfico, mediante la realización de entrevistas en profundidad, abordamos las formas de vida locales. El análisis de los datos es realizado a través del análisis del discurso. En el primer apartado destacamos la diversidad de formas existentes para conceptualizar al estrato orgánico: resaltando el carácter dinámico e híbrido de los saberes científicos y locales, indagamos sobre las maneras en que los diferentes agentes recrean elementos de sentido de diversos órdenes de discurso, y mostramos que los saberes locales conforman un modelo propio. En el segundo apartado destacamos cómo la valoración del estrato, en este contexto sociohistórico singular, es debatida y puesta en discusión, y mostramos que los grados de apropiación del discurso ambiental dependen del grado de participación en las disputas por la definición de las formas de uso y apropiación del ambiente. Finalmente, señalamos la importancia de este tipo de análisis para contribuir a la comprensión de las disputas entre diferentes agentes en los procesos de construcción de los territorios.

Federalismo de concertación y nuevas formas de gobierno de espacios interjurisdiccionales. El caso del sitio Ramsar Delta del Paraná

El sitio Ramsar Delta del Paraná comprende un territorio de 240.000 hectáreas localizadas en las provincias de Entre Ríos y Santa Fe. Fue inscripto en la lista de Humedales de Importancia Internacional creada por la convención del mismo nombre en 2016. Para la gestión de este sitio se conformó un Comité Intersectorial de Manejo (CIM) conformado por las representaciones de ambas provincias, la Administración de Parques Nacionales y diversas instituciones interesadas en la gestión del sitio, incluyendo aquellas que nuclean saberes académicos. La participación ciudadana se canaliza a través de organizaciones de la sociedad civil (mayoritariamente ONG’s) que realizan acciones territoriales en el Delta del Paraná. En este artículo nos proponemos caracterizar la forma de organización estatal que se pone en práctica para gobernar este territorio interjurisdiccional y las nuevas demandas de este sitio en particular para el federalismo

Ichthyoarchaeology on a site located in the border of the alluvial plain of the Paraná River: Familia Primón case (Santa Fe, Argentina)

The present study aims at presenting and discussing the variability of ichthyoarchaeological remains recovered from the Familia Primon (FP) site, located at a border sector of the alluvial plain of the Parana River (Santa Fe, Argentina). To this end, the assemblage was analyzed through its anatomical-taxonomic identification and quantification, and the different taphonomic agents that might have influenced their origin and preservation were evaluated. Also, habitability characteristics for fish and ethnographic data were used to expand the knowledge about certain human behaviors and to generate hypotheses that can be subsequently tested and discussed through the analysis of the ichthyoarchaeological record. In order to establish a micro-regional pattern of exploitation, a comparison with other fish assemblages recovered in archaeological sites situated at the middle stretch and the Parana River Delta was made. The results suggest that fish constituted a central resource for the subsistence of the human groups that inhabited the region during the final period of the Late Holocene.

Diet of the marsh deer in the Paraná River Delta, Argentina—a vulnerable species in an intensive forestry landscape

The marsh deer (Blastocerus dichotomus) is the largest deer native to South America, occurring in wetlands and marshy habitats. The southernmost population of the species is found in the Parana River Delta, Argentina, in a wetland system highly modified by intensive forestry activity. Foresters perceive high levels of economic losses attributed to deer herbivory which drives marsh deer poaching. We carried out the first study of the dietary composition of the marsh deer in this wetland by using microhistological analysis of feces collected seasonally. Seventy-three food items were identified in the marsh deer diet, but only eight had frequencies of > 3% in the annual diet. Macrophytes dominated the diet throughout the year (seasonal percent frequencies 31–42%) due to the high occurrence of Ludwigia bonariensis (24% of average seasonal frequency). Trees, vines, forbs, and shrubs contributed less frequently to the diet, while grasses and grass-like plants were marginally represented (i.e., < 2%). Exotic plant species comprised 38% of the annual diet, and tree species of commercial importance (Salix sp. and Populus R22) were poorly represented (≤ 5.5% per season). The marsh deer in this wetland could be categorized as a browser, differing from the feeding behavior reported for the species in the Brazilian Pantanal (grazer–browser) and suggesting a trophic elasticity in this cervid. Since commercial tree species comprised a very small portion of the diet of this deer, a change in producers’ perception toward the species is needed to diminish this conflict, and our data are important to develop context-specific conservation and management solutions.

Cambios entésicos en guaraníes pre-hispánicos del Delta inferior del Paraná

El objetivo de este trabajo es caracterizar los cambios entésicos de la población horticultora (guaraní) del Delta inferior del río Paraná y compararlos con aquellos de los cazadores-recolectores que habitaron la región hacia fines del Holoceno tardío. Para esto se analizó la robusticidad de las entesis de húmeros, fémures y tibias. Los resultados señalan una amplia variabilidad de cambios entésicos entre los guaraníes que pueden corresponderse con la composición sexual y etaria de la muestra, así como con el tamaño corporal y factores mecánicos. Por otro lado, se observó que los individuos recuperados en sitios guaraníes presentan mayores cambios entésicos que los cazadoresrecolectores. Si bien estas diferencias también podrían estar relacionas con factores biológicos y genéticos, es posible que se deban a diferentes adaptaciones mecánicas relacionadas con sus prácticas de subsistencia y equipamientos tecnológicos.

Situación ambiental del Bajo Delta del Paraná: ¿Qué opinan los pobladores?

The Lower Buenos Aires Delta has received a strong anthropic impact since the XIX century. In 2008, the Ministry of Environment and Sustainable Development of Argentina published a proposal for a Comprehensive Strategic Plan for the Conservation and Sustainable Use of the Parana Delta Region (PIECAS-DP). Among its four central objectives, it was proposed to ensure the participation of all the actors involved. Regarding this proposal, we aimed to conduct surveys to the inhabitants of the Lower Delta of Parana with the purpose of obtaining a first approximation to the perceptions the inhabitants the Delta have about various issues related to the environmental situation of the place where they live. With this objective, a total of 224 interviews were conducted with the inhabitants of the area, covering most of the Lower Buenos Aires Delta. We found that ~75% of the interviewees considered that there is 1) a decrease in water quality, 2) an increase in the amount of garbage carried by rivers and streams, and 3) an increase in the transit of boats. Regarding hunting and fishing, the results indicate that 70.3% of the respondents said they were fishing, while 80.2% said that people hunts, which suggests that both activities are very common in the region. The interviews indicate that inhabitants of the Lower Delta of Buenos Aires perceive a deterioration of the physical environment of the Delta and continue to largely depend on fauna use, both through hunting and fishing.https://doi.org/10.25260/EA.19.29.3.0.799

Comportamiento Mecánico de Barras Esbeltas de Madera Laminada Encolada de Álamo ‘Australiano 129/60’ y ‘Stoneville 67’ (Populus Deltoides) del Delta del Río Paraná Sometidas a Esfuerzos de Compresión

En el año 2016 con la aprobación del primer Reglamento Argentino de Estructuras de Madera, se da un impulso importante al poner a disposición de los profesionales una normativa con criterios de diseño para estas estructuras , con valores de referencias para las especie/procedencia estudiadas, que son la Araucaria angustifolia de Misiones, el Eucalyptus grandis de Entre Ríos, el Pinus Taeda - Elliottii de Misiones y Corrientes y el Populus deltoides del delta del río Paraná. Con la utilización de elementos laminados encolados surge la necesidad de un proceso de fabricación que asegure la buena prestación. En Argentina las normas IRAM 9660/1/2 y 9661 del año 2015 establecen las pautas de fabricación y control para estos elementos estructurales. En este trabajo el objetivo del estudio es determinar el comportamiento resistente y elástico de barras esbeltas de madera laminada encolada de Populus deltoides ‘Australiano 129/60’ y ‘Stoneville 67’ cultivado en Argentina, sometidas a esfuerzos de compresión. Se desarrolló el cálculo teórico de la tensión crítica según los criterios del reglamento INTI-CIRSOC (2016a) y Eurocódigo 5 (EN 1995-1-1 2005) para barras esbeltas comprimidas en piezas de madera encolada de Populus deltoides a los efectos de evaluar el nivel de seguridad que proveen los procedimientos de cálculos, verificar las diferencias entre ambos y comparar los resultados obtenidos de los ensayos de 320 barras esbeltas.

Preliminary Study on Effect of Agricultural Activities in Pollen Spectrum of Argentinean Honey

Abstract Honey floral origin is determined by the harversting region, but anthropogenic factors as agriculture expansion might modify the environmental flora and consequently honey floral origin. Argentina is one of the most important honey producers worldwide which, since the 1990s, has undergone an important agriculture transformation by the adoption of transgenic crops like soybean (Glycine max). However, little is known about the effects of this anthropogenic activity on the floral origin of honey or the statistical tools that could be used to analyse it. The objective of the present study was to evaluate the impact that these environmental modifications have on the pollen spectrum of honey. In order to achieve this, thirty-two samples of blossom honey were collected from three different ecoregions of the Buenos Aires province: Parana Delta and Islands, Espinal and Pampa, in two different years: 1999 and 2014. The pollen spectrum of honey samples was determined and the data obtained was analysed with multivariate statistical techniques. It could be concluded that the pollen composition of honeys from different ecoregions has significantly changed in the past years because of agriculture expansion and adaptation of transgenic crops (p=0.007). Honey samples harvested in 1999 were characterized by high values of Helianthus annuus, while in 2014 an important presence of Eryngium sp., Gleditsia triacanthos, Baccharis type, Trifolium sp. and Glycine max was observed. The present results show that honey palynological results and multivariate statistical analysis could be used as a preliminary attempt to evaluate environmental modifications.

A Newly Detected Exotic Ambrosia Beetle in Argentina: Euwallacea interjectus (Coleoptera: Curculionidae: Scolytinae)

Fil: Landi, Lucas. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion de Recursos Naturales. Instituto de Recursos Biologicos; Argentina

The invasive freshwater bivalve Limnoperna fortunei in South America: multiannual changes in its predation and effects on associated benthic invertebrates

The invasive golden mussel Limnoperna fortunei is known to strongly affect benthic communities in South American freshwaters, but the evolution of these effects after the early invasion stages is poorly understood. Using predator exclusion (covered with 15- and 40-mm meshes) and inclusion (unprotected) substrates, we investigated the interaction between golden mussels and benthic invertebrate communities at different levels of exposure to predators in the Parana River delta. Colonization of the substrates was largely dominated by the mussels. Oligochaeta, Nematoda, and Hirudinea were the most abundant accompanying groups, while Rotifera, Tardigrada, Copepoda, Cladocera, Chironomidae, Gastropoda, Hydracarina, Amphipoda, and nauplii appeared sporadically. Regardless of their different trophic modes and functional attributes, the numbers and biomass of associated invertebrates were not only enhanced by protection against predators, but also by the presence of mussel colonies. Enhancement of invertebrate densities associated with mussel colonies was higher on unprotected than protected substrates, suggesting that invertebrate facilitation increases with increasing predation pressure. Comparisons with a similar study carried out a decade earlier suggest that, after two decades of invasion, the reproductive potential of the mussel, the predation pressure on its colonies, and its facilitation effects on other invertebrates have increased in the Parana River delta.

Floristic enrichment of the understory increases forage production and carrying capacity of temperate silvopastoral systems

In silvopastoral systems, the use of land for multiple purposes diversifies economic income and improves the stability of the system. If shading levels are medium or high, cattle production is often limited by the absence of one or more forage components of the herbaceous layer (such as perennial grasses). In the present study, we hypothesized that perennial C3 cover is a major determinant of cattle production because pasture cover throughout the year is higher and more persistent than that of annuals C3 and thus forage productivity is more stable over time. Therefore, we studied the introduction of orchardgrass into a silvopastoral system of the Parana River Delta (Argentina) and estimated forage production and carrying capacity of the enriched grassland. Between March 2013 and December 2014, we measured forage production and cover in four paired stands either sown (S) or not sown (NS) with C3 grasses by successive harvests of the herbaceous component. The contribution of the different plant functional types to annual forage production was separated across seasons and livestock potential was estimated through carrying capacity. S stands had 105% higher annual forage production than NS stands (S: 2.546 vs. NS: 1.240 kg ha−1 y−1, p = 0.037), with forage species (C3, C4, orchardgrass, Fabaceae) contributing 98.8% to total biomass. The greatest forage production gap between S and NS stands was in winter (S: 594 vs. NS: 23 kg ha−1 90 day−1), when carrying capacity increased ten times in S stands. This is the first research in the area that describes grassland composition and forage production in the understory of plantations, with substantial improvements in livestock carrying capacity of silvopastoral systems.

Usos y percepciones de la fauna silvestre por pobladores de dos barrios aledaños a la Reserva Natural Otamendi, Campana, Argentina

La Reserva Natural Otamendi (RNO), ubicada en el partido de Campana, Provincia de Buenos Aires, posee ambientes propios de la Region Pampeana y del Delta del Parana. La matriz del paisaje esta formada por agroecosistemas, y la RNO preserva, por ejemplo, parches de pastizal pampeano, parches de bosque de tala (Celtis tala) y parches de bosque ribereno. En la comunidad aledana a la reserva se evaluaron las referencias al uso de fauna silvestre y las percepciones de dicha fauna. Se llevaron a cabo entrevistas a pobladores locales, contactados a traves de la Administracion de Parques Nacionales. Ademas, para ampliar la muestra se utilizo la tecnica bola de nieve. Los resultados mostraron tres usos principales de la fauna silvestre: para alimento, para comercializacion o como mascotas. Los mamiferos resultaron ser los animales mas importantes para los pobladores que cazan fauna silvestre. Las especies mas referenciadas y, por lo tanto, de mayor valor de uso fueron el coipo (Myocastor coypus), el carpincho (Hydrochaeris hydrochaeris) y el ciervo de los pantanos (Blastocerus dichotomus). Se constato la practica de la caza en la zona aledana a la RNO y se identificaron los conflictos que esta practica genera entre los pobladores y las autoridades de la zona. A partir de este trabajo, se sugiere ampliar los estudios acerca de los usos de fauna en el area. Asimismo, se estima importante que en los espacios comunes de reunion de los pobladores locales se refuerce la divulgacion del estado de conservacion de las especies con valor de uso en la region, con el fin de establecer y evaluar bases sustentables para su conservacion.https://doi.org/10.25260/EA.17.27.2.0.311

The coastal ridge sequence at Rio Grande do Sul: A new geoarchive for past climate events of the Atlantic coast of southern Brazil since the mid Holocene

Abstract We present here the first geochronometric analysis of a large succession of coastal ridges that developed south of Rio Grande do Sul inlet, aided by OSL dating of samples taken in this succession that amounts c. 306 coastal ridges. This succession allows defining epochs of enhanced coastal drift or fluvial transport to the river mouth. Additionally, changes in the preservation of ridges also suggest the additional effect of transverse winds that create blow outs, while changes in the ridge packages planview onlap suggest possible changes in the dominant longshore drift. Four OSL samples located strategically allow defining the age of five main stages of this succession. The first stage comprises 2 substages. The first substage shows ridges #1 to #36 onlapping the boundary coastal scarp northwardly, while the second (ridges #37 to #84) shows an inversion of ridge shape wedging out southwards until coast returns to be quasi parallel to the initial coastal scarp estimated to be c. 6 ka. We estimate this first stage to comprise enhanced coastal drift due to higher and sandier ridges, ending at c. 4.1 ka. The second stage (ridges #85 to #124) ridges is marked by a slight unconformity, and indicates a period of enhanced fluvial progradation and less coastal drift suggesting milder winds up to 3.6 ka. The third stage (ridges #125 to #204) initiates with erosion of ridges near the delta front, being higher and sandier ridges, suggesting enhanced coastal drift due to windier conditions, being the windiest time bracketed between 3.3 and 2.35 ka. The fourth stage (ridges #205 to c. #270) shows again, as second stage, a tendency of wedging out southwards, suggesting enhanced fluvial progradation, estimated between 2.34 and 1.7 ka. The fifth stage is defined by a complete change of coastal plain progradation, due to the rapid recycling of beach ridges into a complex of blow outs and arcuate sand dunes. Ridges are sparsely recognized in cases they developed during short lived events of enhanced longshore drift, with an outstanding group (ridges #288 to #290) that we correlate to a 1.1–0.9 ka cooling event. Future studies, improving the chronostratigraphy of the beach ridges succession at Rio Grande and comparing it with the Parana river delta ridges, will help understanding the complex environmental history of South America, that include a reversal of the longshore drift, given the fact they are among the most complete upper Holocene geoarchives available.

ПАРАГВАЙЦЫ В ЛЕСНОЙ ОТРАСЛИ ЭКОНОМИКИ АРГЕНТИНЫ

This paper analyses the participation of Paraguayan migrant men in the forestry labor market of the Parana River Delta. Although forestry is not the principal activity in which these migrants work in Argentina, this case is relevant to show the way in which discrimination mechanisms based on ethno-national stereotypes make cheap foreign labor available. At first, based on the last Argentine Population Census, we show that Paraguayans are the most important migrant group in Argentina. Second, we describe the socio-demographic features of the Paraguayan population in the Parana River Delta, and compare them with the trends in other places of destination in Argentina. Finally, based on our ethnographic research developed in the Delta, we analyze the labor hierarchies of forestry production; local discrimination discourses against Paraguayans; migratory networks that make these laborers available; and their working and living conditions. We argue that the expansion and profitability of forestry production in the Parana River Delta is enabled by this segmented labor market that assigns migrant young men to the lowest positions of the labor hierarchy.

Horticulturists and oxygen ecozones in the tropical and subtropical forests of Southeast South America

We analyse the isotopic values (δ13C, δ15N) of the diet of pre-Columbian horticulturalist populations from tropical and subtropical areas of southeastern South America, belonging to the Guarani and Taquara archaeological units. The data indicate different trends in each one (T = 4.21; P = 0.0004), showing a mixed diet with maize consumption in the Guarani samples (δ13Cco = −15.5 ± 1.8‰; δ13Cap −10.4 ± 0.8‰) and a depleted one in the Taquara ones (δ13Cco −18.2 ± 1.7‰; δ13Cap −11.9 ± 0.9‰), with a significant internal dispersion in both populations. The first population has higher nitrogen values (δ15N 11.1 ± 0.6‰) compared to the Taquara samples (δ15N 9.3 ± 1‰), suggesting a more carnivorous diet. The recognition of these pre-Columbian mixed diets involves the identification of maize cultivation on the Atlantic side of the southernmost area of South America (Parana Delta, 34° SL). Through the analysis of δ18O we have identified two isotopic ecozones, the first along the Paraná River Valley, with an average value of δ18O −3.7 ± 0.5‰ (CV = 13.5%; CI = −3.83 / −3.16), and the second one, located in the Planalto of southern Brazil (Araucaria Forest), with a mean value of δ18O −1.5 ± 0.3‰ (CV = 16.5%; CI = −1.69 / −1.29). The isotopic data (δ13C, δ15N and δ18O) suggest human movements between these two ecozones.

Nuevos Datos para las Inhumaciones en Urnas de Sitios Arqueológicos Guaraníes del Extremo Meridional de la Cuenca del Plata

Many urn burials were recorded among the complex mortuary behaviors observed in archaeological sites belonging tothe Guarani archaeological unit. Urn burial analyses are generally scarce and, particularly, in the southern point of La Plata basin. The objective of this work is to contribute to the Guarani society’s knowledge by the analysis of human remains buried in urns from archaeological sites located in the Parana Delta (Argentina). This region is the southern point of this Amazonian group’s expansion, whose mortuary remains are well preserved, in contrast to other Guarani´s regions. In this work, we analyze the human skeletal remains recovered from urn burials from three archaeological sites located in the Parana Delta: Arroyo Malo, Arroyo Fredes y Arroyo La Glorieta. These sites were excavated at the beginning of the 20th century by many researchers and today are part of Museo de La Plata´s collections. We studied sexual composition, age and anatomical structure as well as a set of taphonomic variables. The results show the preponderance of male adult individuals, represented mainly by long bones and cranial elements, some of them with cut marks and red paint (ochre) in abundant quantities. These indicators, along with others of taphonomical origin, indicate the secondary treatment of the dead product of the disassembly, defleshing and selection of certain anatomical units.