Pampas Region Of Argentina Research Articles

Weather Conditions Associated with the Release and Dispersal of Zymoseptoria tritici Spores in the Argentine Pampas Region

The abundance of Zymoseptoria tritici ascospores and conidia in a field was examined throughout two one-year periods (1998-1999 and 1999-2000) establishing the relationship between spore release and weather variables. Radiation, temperature, intensity of rainfall, and relative humidity significantly affected the dispersal of ascospores and pycnidiospores of this pathogen. Spore traps collected both types of spores, at weekly intervals, at two different stages of the wheat crop (vegetative and wheat stubble stages) and different distances from the sources. Ascospores were the predominant sources of inoculum in the field. The numbers of ascospores and pycnidiospores declined with the increase of distance from the sources. The release of pycnidiospores was associated with the increase in rainfall intensity 7 days before the released event and the increase in radiation 60 days before the same event. Relative humidity 3 and 15 days before the release event was positively correlated with ascospores release and negatively correlated with radiation and temperature in all the sampling interval. Also for the first time, a positive correlation between radiation and pycnidiospores dispersal is reported. Understanding the relationship between environment conditions and spores dispersal event could improve the control strategies of the disease.

Amphibians of northwestern Buenos Aires province, Argentina: checklist, range extensions and comments on conservation

Northwestern Buenos Aires province is located within the Pampas region of Argentina. Agricultural practices have extensively modified native grasslands in a relatively short period, leaving no intact pristine areas. Based on data collected between 2006 and 2015 at 153 ponds in agricultural landscapes, we compiled an annotated list of the amphibians of northwestern Buenos Aires province. We report 13 extant species of amphibians, which represent 43% of the known amphibian diversity in Buenos Aires province, and extend the ranges of three species. Three species found only in herpetological collections extend the list to 16 species. Our study is the first long-term survey of amphibians conducted in this part of Argentina and provides valuable information for future conservation actions across agricultural landscapes.

Assessing Organic Phosphorus Contributions for Predicting Soybean Response to Fertilization

Core Ideas The contribution of P indices that include organic P to predict soybean P fertilization response was evaluated. Bioavailable P and MA‐P indices correlated with soybean relative yield. MA‐P index correlated with labile organic P fractions. MA‐P index improved the accuracy to predict soybean yield response to applied P. The use of organic P fraction in soil test P for soybean [Glycine max (L.) Merr.] under no‐till could improve the accuracy to predict crops response to P fertilization. The research objectives were to assess the contribution and accuracy of P indices that include organic‐P fractions to predict soybean yield response to P fertilization in comparison with Bray soil test P (BP). The study included P fertilization experiments conducted in the Pampas Region of Argentina during three growing seasons. We selected sites considering Cate and Nelson quadrants (I, II, III), established by a critical BP concentration of 9 mg P kg−1 and a relative soybean yield (RY) of 85%. Bray P, bioavailable (BioP), particulate (POM‐P), and mineral‐associated (MA‐P) soil P fractions were determined in soil samples from the 0‐ to 5‐cm and 0‐ to 20‐cm depths. Bray P varied from 4.8 to 31 mg P kg−1 and BioP from 8 to 29 mg P kg−1 at the 0‐ to 20‐cm depth. Phosphorus content in POM ranged from 19 to 171 mg P kg−1, and MA‐P ranged from 208 to 446 mg P kg−1. Bioavailable P and MA‐P correlated with RY, whereas POM‐P did not. Bioavailable P performed similarly to BP test to predict soybean yield response to P fertilization. Phosphorus content in MA fraction reduced Cate–Nelson classification errors, improving the accuracy to predict soybean yield response to applied P in comparison with BP test. Sampling at the 0‐ to 5‐cm depth did not improve soil test P performance compared with the 0‐ to 20‐cm depth.

Time-activity budgets and hunting behavior of the Roadside Hawk (Rupornis magnirostris) and the Long-winged Harrier (Circus buffoni)

We conducted a study aimed to evaluate and compare the behavioral patterns of the Roadside Hawk ( Rupornis magnirostris ) and the Long-winged Harrier ( Circus buffoni ), two common but poorly known Neotropical raptors. From 2005 to 2008, we quantified the time-activity budgets of both raptors at the Pampas region of Argentina in order to determine their allocation of time to different activities, their foraging strategies and hunting modes, and whether their behavioral patterns change in different habitats and seasons. The Roadside Hawk and the Long-winged Harrier showed dissimilar activity patterns. Hawks devoted more time to perching (45.5% of total time) than harriers (13%), whereas harriers devoted more time to foraging (45%) than hawks (13%). No differences were found in the time they devoted to fly. In addition, both species differed in the use of flying modes, perching sites, and habitat types. Hawks preferably used cruising flights, perched on tall poles or trees, and were found in woodlands and urban areas. Harriers preferably used soaring and circle flights, perched on the ground, and were found in grasslands and agroecosystems. Notwithstanding, the most obvious difference between these raptors were their hunting modes: the Roadside Hawk behaved as a sit-and-wait predator and the Long-winged Harrier as a wide-foraging predator. These patterns seem to be consistent in different habitat contexts and showed certain differences between seasons. Our results suggest that these species may segregate spatially by utilizing different hunting habitats as well as behaviorally, by using different hunting modes.

A New Approach to Weed Management to Mitigate Herbicide Resistance in Argentina

The evolution of herbicide-resistant weeds is a major concern in the corn- and soybean-producing Pampas region of Argentina, where growers predominantly plant glyphosate-resistant crop varieties and depend heavily on glyphosate for weed control. Currently, 16 weed species in Argentina are resistant to one or more of three different herbicide mechanisms of action, and resistant weed populations continue to increase, posing a serious threat to agricultural production. Implementation of integrated weed management to address herbicide resistance faces significant barriers in Argentina, especially current land ownership and rental patterns in the Pampas. More than 60% of Pampas cropland is rented to tenants for periods that rarely exceed 1 yr, resulting in crop rotation being largely abandoned, and crop export taxes and quotas have further discouraged wheat and corn production in favor of continuous soybean production. In this paper we discuss ways to facilitate new approaches to weed management in Argentina, including legal and economic reforms and the formation of a national committee of stakeholders from public and private agricultural sectors.

Mapping the soils of an Argentine Pampas region using structural equation modelling

Current digital soil mapping (DSM) methods have limitations. For instance, it is difficult to predict a large number of soil properties simultaneously, while preserving the relationships between them. Another problem is that prevalent prediction models use pedological knowledge in a very crude way only. To tackle these problems, we investigated the use of structural equation modelling (SEM). SEM has its roots in the social sciences and is recently also being used in other scientific disciplines, such as ecology. SEM integrates empirical information with mechanistic knowledge by deriving the model equations from known causal relationships, while estimating the model parameters using the available data. It distinguishes between endogenous and exogenous variables, where, in our application, the first are soil properties and the latter are external soil forming factors (i.e. climate, relief, organisms). We introduce SEM theory and present a case study in which we applied SEM to a 22,900km2 region in the Argentinian Pampas to map seven key soil properties. In this case study, we started with identifying the main soil forming processes in the study area and assigned for each process the main soil properties affected. Based on this analysis we defined a conceptual soil-landscape model, which was subsequently converted to a SEM graphical model. Finally, we derived the SEM equations and implemented these in the statistical software R using the latent variable analysis (lavaan) package. The model was calibrated using a soil dataset of 320 soil profile data and 12 environmental covariate layers. The outcomes of the model were maps of seven soil properties and a SEM graph that shows the strength of the relationships. Although the accuracy of the maps, based on cross-validation and independent validation, was poor, this paper demonstrates that SEM can be used to explicitly include pedological knowledge in prediction of soil properties and modelling of their interrelationships. It bridges the gap between empirical and mechanistic methods for soil-landscape modelling, and is a tool that can help produce pedologically sound soil maps.

Suspended sediment concentration controlling factors: an analysis for the Argentine Pampas region

ABSTRACTIn the Argentine Pampas region, there is little information about sediment concentration in agricultural catchments. The aims of this work are: (1) to analyse fluctuations in sediment concentration and discharge, as a first attempt to characterize hysteresis patterns; and (2) to study sediment concentration controlling factors and to assess the importance of these factors using principal component analysis and a multiple regression model. Twenty-five events registered during 4 years in a 560 ha gauged basin of Argentina were studied. Analysis of data suggested a positive clockwise pattern. The multiple regression model was performed with three factors obtained by principal component analysis: runoff, precipitation and antecedent conditions. The model explained 83% of the variability of sediment concentration. The runoff factor contributed to modelled sediment concentration with the highest magnitude, followed by precipitation and antecedent condition factors. Although the watershed is under conservation tillage, rill erosion seems to be the main source of sediment concentration.Editor M.C. Acreman; Associate editor X. Fang

Available phosphorus in the central area of the Argentinean Pampas. 2: Kinetics of adsorption and desorption of phosphorus under different soil and management environments

The concentration of phosphate ions in solution is critical in defining the ability of a soil to adequately meet crop demand. That concentration is regulated by adsorption/desorption and precipitation/dissolution processes, particularly its kinetics of reaction. This work was developed in order to find the kinetic model describing the sorption/desorption of phosphate in soils of the Argentinean Pampas region, to describe the processes associated with these reactions and to define the effect of temperature on them. A bi-linear model that adequately describes the data obtained in the adsorption and desorption experiments is proposed. Thus, it was possible to clearly differentiate two different kinetic mechanisms, each characterized by different reaction rates. Two very labile pools of phosphorus were determined in these soils. The rate at which these processes occur indicates the occurrence of chemical reactions of precipitation in highly soluble compounds and surface adsorption reactions with very low binding energy, as P is quickly released into the soil solution in the desorption process. However, since the amounts of P released in the desorption process are very much less than the adsorbed, is possible to infer that both processes occur at non-equilibrium conditions and there is a lack of reversibility of the reaction P-Soil – P-Solution in the soils studied. The intensity of these processes is differentially affected by temperature and, in general, there is a positive effect of phosphorus fertilization history, although the effect of this is not clearly seen in the amounts of extractable phosphorus with the classic Bray & Kurtz N°1 method.

Distribución y variabilidad morfológica de poblaciones de Solanum commersonii (Solanaceae) en la región pampeana de la Argentina.

Solanum commersonii es una especie tuberosa silvestre de papa ampliamente distribuida en el Distrito Pampeano Austral y Oriental de la Argentina, creciendo en ambientes muy diversos: en la costasobre médanos e integrando pastizales relictuales de paja colorada tanto en campos bajos con limitantes edáficas como en las laderas de la sierras. Con el objetivo de comparar las poblaciones provenientesde diferentes sitios y ambientes se analizaron 17 poblaciones de Solanum commersonni, una entrada de Solanum malmeanum y una de Solanum chacoense, estas dos últimas utilizadas como grupostaxonómicamente relacionados. Se registraron 41 caracteres morfológicos vegetativos y reproductivos, en seis a diez plantas por población. Los datos fueron analizados mediante un análisis de varianza, de coordenadas y componentes principales. Se calculó un árbol de mínima distancia para visualizar los posibles agrupamientos. Los resultados del análisis morfológico detectaron que la variabilidadintraespecifica en las poblaciones estudiadas de S. commersonii no está asociada a los diferentes ambientes donde crece la especie.

Asiatic Callosciurus squirrels as seed dispersers of exotic plants in the Pampas.

Seed dispersal by exotic mammals exemplifies mutualistic interactions that can modify the habitat by facilitating the establishment of certain species. We examined the potential for endozoochoric dispersal of exotic plants by Callosciurus erythraeus introduced in the Pampas Region of Argentina. We identified and characterized entire and damaged seeds found in squirrel faeces and evaluated the germination capacity and viability of entire seeds in laboratory assays. We collected 120 samples of squirrel faeces that contained 883 pellets in seasonal surveys conducted between July 2011 and June 2012 at 3 study sites within the main invasion focus of C. erythraeus in Argentina. We found 226 entire seeds in 21% of the samples belonging to 4 species of exotic trees and shrubs. Germination in laboratory assays was recorded for Morus alba and Casuarina sp.; however, germination percentage and rate was higher for seeds obtained from the fruits than for seeds obtained from the faeces. The largest size of entire seeds found in the faeces was 4.2 × 4.0 mm, whereas the damaged seeds had at least 1 dimension ≥ 4.7 mm. Our results indicated that C. erythraeus can disperse viable seeds of at least 2 species of exotic trees. C. erythraeus predated seeds of other naturalized species in the region. The morphometric description suggested a restriction on the maximum size for the passage of entire seeds through the digestive tract of squirrels, which provides useful information to predict its role as a potential disperser or predator of other species in other invaded communities.

Do agrochemicals used during soybean flowering affect the visits of Apis mellifera L.?

In the Pampa region of Argentina, most beehives are situated near to soybean [Glycine max (L.) Merr.] crop and honey bees (Apis mellifera L.) use its floral resources. Soybean is often sprayed with pesticides but very little is known about their repellent action against bees. This study evaluates the visit of honey bees to crop after the application of agrochemicals aiming to check for repellency of them and estimate the possible impact on crop pollination. For this, six treatments were used (glyphosate + cypermethrin; glyphosate; cypermethrin; lambda-cyhalothrin; methoxyfenocide; Bacillus thuringiensis) and developed on plots of 625 m2, located in Oro Verde (Argentina), applying two sprays during the crop flowering. The bees were captured using entomological net every 4 days in three different times from the day after the first spraying and up the end of crop flowering. The results showed very little or no repellent action of pesticides on A. mellifera, noting that it foraged on soybean flowers regardless of the temporal proximity and the type of product used in sprays. Possible causes are discussed and the need for larger studies is evident in field conditions related to pesticides repellency and mixtures. Also, further evaluation of the effects of the different chemical formulations available on the market and used regionally where the subspecies A. mellifera can be found. Simultaneously some management practices that could help minimize the risk of contamination are mentioned; the use of defensive crop products of biological origin is encouraged as well as further research in this topic.

Paleobiology of sabretooth cat Smilodon populator in the Pampean Region (Buenos Aires Province, Argentina) around the Last Glacial Maximum: Insights from carbon and nitrogen stable isotopes in bone collagen

The sabretooth cat Smilodon populator was the largest felid in South America. It appears in the fossil record in the Early Pleistocene, as an immigrant from North America, and becomes extinct around the Pleistocene–Holocene boundary. The carbon and nitrogen stable isotopic values of collagen were measured for skeletal remains from Smilodon specimens ranging in age from 25 to 10kyrBP, for the first time in the Pampas region of Argentina. By comparison with similar values obtained on co-eval predators such as Protocyon (large canid) and Panthera onca (jaguar) and a range of potential prey, such as giant ground sloths, glyptodontids, Macrauchenia, Toxodon, equids, cervids, and rodents, it could be established that Smilodon consumed essentially large prey from open landscape, such as Macrauchenia and giant ground sloths during the last 15,000years of the Late Pleistocene in the Pampa region. It was possibly competing with the large canid Protocyon but the jaguar was apparently feeding on smaller size prey. A more humid climate at the beginning of the Holocene might have been unfavorable to this large predator and could have contributed to its extinction. These results also provide an important insight to understand the ecological processes involved in the Great American Biotic Interchange.

Water erosion and connectivity analysis during a year with high precipitations in a watershed of Argentina

Soil erosion is a global concern because of its consequences for the environment and the economy of countries. In the Argentine Pampas Region, soil erosion process is a priority issue, although there is little information about sediment concentration (SC) in agricultural catchments. The study aimed at assessing the factors that have a major influence on SC and discussing the dynamics of hydrological and sedimentological connectivity during 2012, a year with precipitation over the mean and significant erosive events. The study was conducted in a watershed of Buenos Aires province, Argentina. A linear regression model, that considered autocorrelation, was obtained. Maximum rainfall intensity in 30 minutes and peak flow were related to SC. An analysis of satellite images was carried out to discuss the hydrological connectivity, and a connectivity index was calculated to assess changes in sedimentological connectivity. The analyses suggested increments in hydrological and sedimentological connectivity, associated with the drainage area expansion and with water erosion rills. Hydrological connectivity is needed for sedimentological connectivity. However, increments in sedimentological connectivity may have been conditioned by the input of energy to detach and to transport particles. This may have been evidenced when flows exceeded a threshold runoff coefficient.

Effect of watertable depth and salinity on growth dynamics of Rhodes grass (Chloris gayana)

Depending on their depth, watertables can have a positive effect on plants by supplying water, a negative effect by creating waterlogged and/or saline conditions or a neutral effect. Rhodes grass (Chloris gayana), a tropical perennial forage adapted to saline soils, floods and droughts, is a viable choice for the lowlands in the Pampas region of Argentina. The effects of the depth and salt concentration of the watertable on the growth dynamics and biomass accumulation of Rhodes grass were quantified in a greenhouse experiment. The experiment consisted of 10 treatments, resulting from the factorial combination of five watertable depths (25, 75, 125, 175 and 225 cm) and two salt treatments (EC 1.4 and 20.5 dS m–1). The presence of non-saline watertable at a depth of 25 cm produced a 5-fold greater biomass and showed an increase in water consumption of equal magnitude compared with deeper watertables. The increase in shoot biomass was explained primarily by higher tiller and stolon density, which increased 3.3- and 7.7-fold respectively, at watertables that were 25 cm deep compared with deeper treatments. Furthermore, groundwater use efficiency was 30% higher in non-saline watertables at 25 cm depth. Similarly, at this depth, the leaf blades were 50% longer compared with the deepest watertables evaluated. In contrast, the presence of saline watertables at 25 cm depth had a detrimental effect on the production of biomass and its components, whereas the effect at 125 cm and greater depths was neutral. Therefore, Rhodes grass is a species that can take advantage of the widespread shallow watertable environments of the Pampas region as long as the salinity levels are low.

Effect of Good Agricultural Practices under no-till on litter and soil invertebrates in areas with different soil types

Good Agricultural Practices (GAPs) under no-till (NT) includes a mixed crop rotation; cover crops; integrated pest, weed and disease management; nutrient restoration; and a rational use of agrochemicals. When applied all together, GAPs promotes high productivity, while maintaining the production capacity of resources. In the Pampas region of Argentina, there is a need to assess the effects of these practices on soils, particularly on soil fauna, as they play an important role in soil functioning. The aim of this study was to evaluate the effect of the application of GAPs under NT on invertebrates and to assess whether this effect is different between soil types. We hypothesized (1) that GAP will produce an increase in the abundance, as well as changes in the faunal composition of litter and soil invertebrates; (2) that the effects will differ with soil type, and (3) that the changes in soil invertebrate fauna will be explained by soil properties. We compared two contrasting NT treatments -with and without GAP application-, replicated in three agricultural areas, on different soil types (Entic Haplustolls to Typic Argiudolls) situated across a west–east transect in the Pampas region of Argentina. A positive (Natural environment) and a negative (Conventional tillage) reference sites were included in the comparison. Litter and soil invertebrates and soil properties were assessed at each sampling site. Overall, our results indicated that the application of GAPs in productive NT fields increases litter and soil invertebrate abundance and modifies faunal composition. In the litter layer, four of the five taxa present were favoured by GAPs with an increase in the abundances of ants, prostigmatid mites, earthworms and collembolans. GAPs also induced changes in invertebrate faunal composition, from the initial NO-GAP situation to the present state under GAP system. The observed changes in litter and soil invertebrates, changes in faunal abundance and composition can be expected to translate to changes in soil functioning. Our last hypothesis was partially confirmed in that soil properties have to be considered in the examination of differences in fauna between treatments with there are only subtle differences in practices, as in the present study.

Morphometric Differentiation in a Field Population ofDichroplus maculipennis(Orthoptera: Acrididae: Melanoplinae) under Outbreak and Non-Outbreak Situations

Abstract Dichroplus maculipennis is one of the most damaging grasshopper species of Argentina. Individuals of this species at high density are historically known to show aggregation behavior and dispersal flights, attributes that might suggest that it does exhibit to some extent phase polyphenism in relation to population density. Phase polyphenism is a complex phenomenon and the amplitude of phase change is usually species-dependent. Morphological differences between gregarious and solitarious locusts can be measured and analyzed in order to characterize the phase status. The objective of this study was to evaluate morphometric differences between individuals of a D. maculipennis field population in the southern Pampas region of Argentina during non-outbreak and outbreak conditions including the magnitude of sexual size dimorphism related to variation in density. Collected individuals in the outbreak condition totaled 804 (422 females, 382 males) and those in non-outbreak condition were 325 (141 females,...

Host gut microorganisms' cues mediate orientation behaviour in the larva of the parasitoid Mallophora ruficauda.

The robber fly Mallophora ruficauda is one of the most important apicultural pests in the Pampas region of Argentina. This species is a parasitoid of scarab beetle larvae. Females lay eggs away from the host, and the larvae perform active search behaviour toward Cyclocephala signaticollis third instar larvae, parasitoid's preferred host. This behaviour is mediated by host-related chemical cues produced in hosts' fermentation chamber. Also, C. signaticollis larvae are attracted to fermentation chamber extracts. As scarab larvae have microbe-rich fermentation chamber, it has been suggested that microorganisms could be involved in the production of these semiochemicals. The aims of this work were first to ascertain the presence of microorganisms in the fermentation chamber of C. signaticollis larvae and second to determine the role of microorganisms in the orientation response of parasitoid and host larvae. We found that microorganisms-free C. signaticollis larvae showed deterioration in their development and did not produce the attractive semiochemicals. Therefore, we isolated fermentation chamber microorganisms of host larvae by means of different cultures media, and then, assayed different microorganisms' stimuli by binary choice tests. We were able to isolate microorganisms and determine that M. ruficauda larvae are attracted to semiochemicals from protein degradation in the fermentation chamber. However, C. signaticollis larvae were not attracted to any semiochemicals associated with microorganisms' activity in the fermentation chamber. Although we were unable to elucidate the exact role of gut microorganisms in host behaviour, we discuss their relevance in parasitoid host-seeking behaviour and host conspecific interaction in M. ruficauda-C. signaticollis system.

The herbage productivity of tall fescue in the Pampas region of Argentina is correlated to its ecological niche

AbstractSince its introduction in the 1950s, tall fescue has spread throughout the Pampas region of Argentina to become naturalized in much of this region. Its annual forage mass productivity shows significant differences among sites. In this work, we hypothesized that, under dryland conditions, the annual forage mass productivity is related to the probability that the corresponding site is within the ecological niche of the species. To test this hypothesis, the spontaneous occurrence of tall fescue was surveyed in an area of 440 000 km2. The abundance of tall fescue was verified on roadsides of national and provincial roads, in systematic sampling points spaced every 50 km. Subsequently, the ecological niche of the species was estimated with the Maxent software, based on the environmental information available. Additionally, the bioclimatic variables with greatest influence in determining the ecological niche were identified. Based on the information of comparative yield trials of tall fescue cultivars, a correlation analysis between annual forage mass productivity and the likelihood of ecological niche was performed. We found that the realized ecological niche of tall fescue in the Pampas region covers an area of 237 000 km2 where the average minimum temperature of the coldest month is between 2·6 and 3·2°C and the rainfall in the driest quarter is 100 mm or higher. We also found that there were significant correlations between annual forage mass productivity and the probability of realized ecological niche. Therefore, in areas with low probability of realized ecological niche, other forage species could be a better option than tall fescue to obtain a high and stable annual forage mass productivity.

The role of small carnivores in the movement of bones: implications for the Pampas archaeofaunal record, Argentina

The use of the same spaces and prey by humans and carnivores often leads to the formation of complex faunal assemblages, in which the anatomical and taxonomic composition results from the combined action of these agents. The aim of this paper is to evaluate bone movement based on actualistic research in the Pampas region of Argentina, with an emphasis on the action of carnivores as agents responsible for transport and accumulation of bone. Number of taxa, percentage of specimens affected by carnivores in each environmental context, skeletal representation and carnivore modifications on European hare from the hills and the coast, and bone movement are discussed. The implications of our actualistic results for the regional archaeological record are also addressed. All of the sampled environments presented evidence of carnivore modifications, with percentages between 9 % (coast) and 40 % (hills). This information demonstrates that this agent plays an active role in the formation of modern bone assemblages in the Pampas region and provides a frame of reference for exploring interpretations about the low percentages of carnivore activity recorded in the archaeological record of the region. We argue that carnivores not only modify an assemblage by incorporating or destroying bones, but also by moving them to other locations. Consequently, carnivore effects on site formation in the Pampas region should not be underestimated when their marks are scarce.

Beached penguins on the Atlantic Coast in the Pampas region of Argentina: Taphonomic analysis and implications for the archaeological record

Abstract This study evaluates a modern natural deposit of Magellanic penguin remains in the coast of the Pampas region, and discusses the regional availability of this resource for prehistoric hunter-gatherer populations, as well as the potential for the natural incorporation of this species into the archaeological record. The penguin assemblage from the surveyed area, which results from beaching during seasonal migration, consists of disarticulated bones, articulated bones, and carcasses. In the skeletal representation, there is a strong predominance of limbs and shoulder girdle elements. Natural processes such as weathering, sedimentary abrasion, and predator action highly affected the preservation of specimens. Even though penguins could have been a potential prey for hunter-gatherer populations of the Pampas region, our results suggest that they were not an attractive food resource given their scarcity and poor nutritional condition. The spatial distribution of modern penguin remains and the archaeological evidence suggest that the natural incorporation of bones from this seabird into surface archaeological sites can be expected in the backshore and deflated interdunes. However, the chances of long term burial and bone preservation are low; thus, the formation of a stratigraphic archaeological site containing intrusive penguin remains in these settings is unlikely.