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This study examines the dynamics of limnological parameters of a South American lake located in southern Chile with the objective of predicting chlorophyll-a levels, which are a key indicator of algal biomass and water quality, by integrating combined remote sensing and machine learning techniques. Employing four advanced machine learning models (recurrent neural network (RNNs), long short-term memory (LSTM), recurrent gate unit (GRU), and temporal convolutional network (TCNs)), the research focuses on the estimation of chlorophyll-a concentrations at three sampling stations within Lake Ranco. The data span from 1987 to 2020 and are used in three different cases: using only in situ data (Case 1), using in situ and meteorological data (Case 2), using in situ, and meteorological and satellite data from Landsat and Sentinel missions (Case 3). In all cases, each machine learning model shows robust performance, with promising results in predicting chlorophyll-a concentrations. Among these models, LSTM stands out as the most effective, with the best metrics in the estimation, the best performance was Case 1, with R2 = 0.89, an RSME of 0.32 µg/L, an MAE 1.25 µg/L and an MSE 0.25 (µg/L)2, consistently outperforming the others according to the static metrics used for validation. This finding underscores the effectiveness of LSTM in capturing the complex temporal relationships inherent in the dataset. However, increasing the dataset in Case 3 shows a better performance of TCNs (R2 = 0.96; MSE = 0.33 (µg/L)2; RMSE = 0.13 µg/L; and MAE = 0.06 µg/L). The successful application of machine learning algorithms emphasizes their potential to elucidate the dynamics of algal biomass in Lake Ranco, located in the southern region of Chile. These results not only contribute to a deeper understanding of the lake ecosystem but also highlight the utility of advanced computational techniques in environmental research and management. [ABSTRACT FROM AUTHOR]

The blooms of Alexandrium catenella, the main producer of paralytic shellfish toxins worldwide, have become the main threat to coastal activities in Southern Chile, such as artisanal fisheries, aquaculture and public health. Here, we explore retrospective data from an intense Paralytic Shellfish Poisoning outbreak in Southern Chile in Summer–Autumn 2016, identifying environmental drivers, spatiotemporal dynamics, and detoxification rates of the main filter-feeder shellfish resources during an intense A. catenella bloom, which led to the greatest socio-economic impacts in that area. Exponential detoxification models evidenced large differences in detoxification dynamics between the three filter-feeder species surf clam (Ensis macha), giant barnacle (Austromegabalanus psittacus), and red sea squirt (Pyura chilensis). Surf clam showed an initial toxicity (9054 µg STX-eq·100 g−1) around 10-fold higher than the other two species. It exhibited a relatively fast detoxification rate and approached the human safety limit of 80 µg STX-eq·100 g−1 towards the end of the 150 days. Ecological implications and future trends are also discussed. Based on the cell density evolution, data previously gathered on the area, and the biology of this species, we propose that the bloom originated in the coastal area, spreading offshore thanks to the resting cysts formed and transported in the water column. [ABSTRACT FROM AUTHOR]

Urban areas form a complex, heterogeneous, fragmented mosaic of habitats, including ecosystems in different degrees of alteration. Nevertheless, some species of birds of prey can thrive in cities. But, there is a knowledge gap regarding the species of birds of prey that who inhabit the cities in Chile, especially those that reproduce in it. Hence, we work in Valdivia, a city that preserves an important natural matrix. The object of this study was to characterize the diversity, abundance, and nest sites of diurnal and nocturnal raptors in the urban area of a city in southern Chile. Twelve species of raptor were recorded, seven diurnal and five nocturnal, 63.1% of the species expected for neighboring rural areas. Twenty-seven nesting sites were recorded two of diurnal raptors and four nocturnal raptors. The availability of nesting sites close to feeding sites, distance to houses, and grassland-shrub cover are essential factors for the success of raptor populations. Cities like Valdivia could offer suitable nesting sites for reproduction, helping to restore habitats for birds of prey. [ABSTRACT FROM AUTHOR]

In this article we analyse the process of identity construction and reconstruction that is occurring on the coasts of southern Chile, in the framework of the formal creation of indigenous associations and communities, including the demands of indigenous peoples for marine coastal spaces. Through a study of ethnographic strategies and the specialist literature, we problematise the appearance of indigenous nomenclatures and symbolisms — in particular Mapuche flags — as a political-ideational correlate of this process. We point out that territorial demands in the marine coastal space of southern Chile possess an instrumental aspect that is superimposed on Mapuche identity narratives, and appears to derive more from deliberate political actions or projects than from a social memory anchored in a historical consciousness of indigenous life. [ABSTRACT FROM AUTHOR]

Mistletoes are parasitic plants that largely rely on animals for pollination and seed dispersal but establish complex interactions with their host plants. Mistletoes are considered keystone species in forest ecosystems as they facilitate several interactions. We studied the fauna associated with two sympatric mistletoe species (Tristerix corymbosus (L.) Kuijt and Desmaria mutabilis (Poepp. & Endl.) Tiegh.) from the temperate rainforests of southern Chile. We set 40 camera traps from November 2021 to May 2022 to monitor the main pollinator (the hummingbird Sephanoides sephaniodes (R. Lesson & Garnot, 1827)), the main seed disperser (the arboreal marsupial Dromiciops bozinovici D'Elía, Hurtado & D'Anatro, 2016), and other animals (birds, mammals, reptiles, and insects). We compared fauna associated with Tristerix corymbosus between spring and summer–fall periods and between Tristerix corymbosus and Desmaria mutabilis during summer–fall. Species composition associated with Tristerix corymbosus showed a significant temporal variation, mainly explained by Sephanoides sephaniodes and Dromiciops bozinovici, which are more abundant in the summer–fall period. We found that animal species composition differences between mistletoe species were mainly explained by S. sephaniodes, Dromiciops bozinovici, and insects. While Tristerix corymbosus was mainly pollinated by hummingbirds, insects frequently visited Desmaria mutabilis flowers. Although both mistletoes have many similarities, they also have some phenology differences that affect their associations with animals, potentially influencing ecological processes. [ABSTRACT FROM AUTHOR]

This study examines the dynamics of limnological parameters of a South American lake located in southern Chile with the objective of predicting chlorophyll-a levels, which are a key indicator of algal biomass and water quality, by integrating combined remote sensing and machine learning techniques. Employing four advanced machine learning models (recurrent neural network (RNNs), long short-term memory (LSTM), recurrent gate unit (GRU), and temporal convolutional network (TCNs)), the research focuses on the estimation of chlorophyll-a concentrations at three sampling stations within Lake Ranco. The data span from 1987 to 2020 and are used in three different cases: using only in situ data (Case 1), using in situ and meteorological data (Case 2), using in situ, and meteorological and satellite data from Landsat and Sentinel missions (Case 3). In all cases, each machine learning model shows robust performance, with promising results in predicting chlorophyll-a concentrations. Among these models, LSTM stands out as the most effective, with the best metrics in the estimation, the best performance was Case 1, with R2 = 0.89, an RSME of 0.32 µg/L, an MAE 1.25 µg/L and an MSE 0.25 (µg/L)2, consistently outperforming the others according to the static metrics used for validation. This finding underscores the effectiveness of LSTM in capturing the complex temporal relationships inherent in the dataset. However, increasing the dataset in Case 3 shows a better performance of TCNs (R2 = 0.96; MSE = 0.33 (µg/L)2; RMSE = 0.13 µg/L; and MAE = 0.06 µg/L). The successful application of machine learning algorithms emphasizes their potential to elucidate the dynamics of algal biomass in Lake Ranco, located in the southern region of Chile. These results not only contribute to a deeper understanding of the lake ecosystem but also highlight the utility of advanced computational techniques in environmental research and management.

The blooms of Alexandrium catenella, the main producer of paralytic shellfish toxins worldwide, have become the main threat to coastal activities in Southern Chile, such as artisanal fisheries, aquaculture and public health. Here, we explore retrospective data from an intense Paralytic Shellfish Poisoning outbreak in Southern Chile in Summer–Autumn 2016, identifying environmental drivers, spatiotemporal dynamics, and detoxification rates of the main filter-feeder shellfish resources during an intense A. catenella bloom, which led to the greatest socio-economic impacts in that area. Exponential detoxification models evidenced large differences in detoxification dynamics between the three filter-feeder species surf clam (Ensis macha), giant barnacle (Austromegabalanus psittacus), and red sea squirt (Pyura chilensis). Surf clam showed an initial toxicity (9054 µg STX-eq·100 g−1) around 10-fold higher than the other two species. It exhibited a relatively fast detoxification rate and approached the human safety limit of 80 µg STX-eq·100 g−1 towards the end of the 150 days. Ecological implications and future trends are also discussed. Based on the cell density evolution, data previously gathered on the area, and the biology of this species, we propose that the bloom originated in the coastal area, spreading offshore thanks to the resting cysts formed and transported in the water column.

Escaped salmonids are considered among the most serious threats to the aquatic environment. One hundred and nine escape incidents were reported in Chile from 2004-2021, representing some 8.53 million escaped salmonids. Of this total, 5.73 million were Atlantic salmon Salmo salar (67.2%), 0.83 million coho salmon Oncorhynchus kisutch (9.8%), and 1.96 million were rainbow trout O. mykiss (23.0%). It is estimated that 70.1% of the escaped salmonids were recorded in the Los Lagos Region, 23% in the Aysén Region, and 4.6% in the Magallanes Region. In total, 80.5% of the escapes were recorded from seawater facilities, while freshwater units accounted for 19.5%. The highest percentage of escaped salmon recorded in seawater over 2004-2021 was 1.71% of harvested salmonids in 2013. Some 39.5% of the escapes in 2015-2021 were attributed to rupturing of net cages, mainly due to adverse climatic conditions. The additional regulations introduced in 2020 by the Chilean authority, has helped to minimize the escape of farmed salmonids. As a consequence, just one escape event was reported in 2021, corresponding to 3.85% of the total number of escapees recorded from 2004-2021. [ABSTRACT FROM AUTHOR]

Raptor conservation programs should be based on knowledge of the birds' ecology in both natural and urban habitats, justifying the inclusion of ecological studies in suburban zones into regional planning initiatives. The objective of this study was to determine the use of diurnal raptors within the habitats of a suburban area of a city in southern Chile. We characterize the different zones into five types of environment, and assess their raptor diversity for consideration in territorial planning. Acoustic surveys were conducted in auditory stations in addition to observations from fixed transects and trails. From a total of 161.39 h of survey, we obtained 664 sightings corresponding to ten species of diurnal raptors. The richest environment was dense forest (eight species), followed by grassland (six species), native forest regeneration (five species), shrubs (four species) and exotic tree plantations (three species). We discuss the relationship between the richness of diurnal raptors, the types of environment in the study area, and the spatial location of the sites, as well as the implications for territorial planning to support the conservation of birds of prey in the suburban zone studied. [ABSTRACT FROM AUTHOR]

This article addresses the emerging issue of migration from cities to the countryside, a trend which increased and became more evident during the COVID-19 pandemic. Specifically, this study follows the population growth of Mapuche communities in southern Chile. It proposes that this migration pattern represents a medium-term pendular historical phenomenon; decades after the initial Mapuche exodus to cities in Chile and Argentina in the 1960s and 1970s, families and individuals have decided to return to live permanently on community lands. This study utilized official Mapuche community resources and interviews with public officials, experts, community members, and Mapuche leaders. This article highlights a very important historical phenomenon, as return migration generates changes in the communities and the southern landscape, as well as posing challenges for the rural world. In some cases, the recent return migration has generated substantial occupation changes for the migrants, resulting in a change from urban to rural activities. In other cases, individuals and families have returned to live in the community but maintained jobs in nearby cities, or have retired. [ABSTRACT FROM AUTHOR]

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ABSTRACT: The poultry industry produces most of the meat and eggs for human consumption worldwide. However, family poultry farming still plays an important role in developing countries providing high quality animal products including eggs and poultry meat for family and local consumption.A field survey was taken to 145 family poultry farmers off the commune of Maullin, Los Lagos Region of Southern Chile, to describe their husbandry and breeding practices, and provide information for future development and conservation priorities. Egg production in these poultry systems of the Maullín commune is a family tradition, run mostly by women, provides an extra income from the sale of extra eggs and chicken meat during autumn and winter months. Flocks of 15 to 30 native, creole or indigenous hens, reach point of lay at 5 or 6 months old. Egg production with a mean rate of 40%, peaks during September. Brown eggs are the most frequent, followed by blue-greenish eggs derived from Mapuche fowl ancestry. A ratio of 10 to 20 females per rooster results in ca. 60% hatching rate from natural incubation. While males are kept for two seasons only, females are kept longer, some until old. Diet is based on locally available or self-produced grains, complemented by pasture browsing, scavenging, and kitchen waste. Sanitary management is low or none and technical knowledge derives from ancestral tradition. Investment in accommodation and feeding is low. Results provide information on these systems in non-tropical areas of developing countries where it is scarce, and highlights how these systems can respond to the challenges of future poultry production, considering both climate change and consumers demand for more wholesome, human and sustainable products.

A study was carried out on two important recreational fishing rivers in southern Chile, the Petrohué and the Puelo, to assess the population structure of the salmonid species inhabiting both rivers. Five river sectors were surveyed on four dates between April 2016 and February 2017. In the Petrohué River, 2400 fish were sampled (42.9% rainbow trout Oncorhynchus mykiss; 23.8% brown trout Salmo trutta, and 33.3% Chinook salmon Oncorhynchus tshawytscha), while in the Puelo River, 1972 fish were examined (51.6% rainbow trout; 30.4% brown trout and 18% Chinook salmon). Fry and fingerling stages accounted for the highest proportion of fish collected by electrofishing. In the Petrohué and Puelo rivers, rainbow trout fry and fingerlings represented 96.3 and 99.2% of the fish sampled, respectively; 96.8 and 97.1% in the case of brown trout, while for Chinook salmon, parr and pre-smolts represented 97% of the fish examined in the Petrohué River and 98.3% in the Puelo River. Rainbow and brown trout shared the same habitats and food items in both rivers, and the two oldest trout recorded 5+ and 6 + years. Parr and pre-smolt Chinook salmon were present mainly in the winter and spring seasons and were aged 1+ and 2+, respectively. There were no differences in the food items recorded from the juvenile fish sampled in both rivers. The mature, returning adult Chinook salmon aged between 1.5+ and 1.6+ years were devoid of food and were recorded over the autumn season with the highest abundance in the Petrohué River. The study did not identify any adverse competition or negative interactions among the three main salmonid species sharing the same habitat. [ABSTRACT FROM AUTHOR]

Lichens are currently interpreted as complex self-sustaining ecosystems formed by the interaction of the primary symbionts and other microorganisms. These microorganisms, which colonize the surface of lichen thalli, could be crucial actors in nutrient cycling. Here, we used PICRUSt2 to predict and compare the potential functions of bacteria closely associated with Peltigera frigida thalli and their substrates. We found that these bacteria could potentially transform organic and inorganic molecules related to nitrogen, phosphorus, and sulfur cycles. Although further experiments to verify these potential contributions are required, these results reinforce the proposal of the nutrient-cycling role of bacteria associated with P. frigida. [ABSTRACT FROM AUTHOR]

Abstract Extra‐pair behavior is present in 76% of socially monogamous bird species with biparental care. This behavior may produce costs to females related to a reduction in paternal care. We estimated the percentage of extra‐pair offspring and quantified paternal care in 44 nests of Thorn‐tailed Rayadito (Aphrastura spinicauda) to assess whether males reduce their parental care when females obtain extra‐pair fertilizations. We used data from a sub‐Antarctic population of Rayadito located on Navarino Island (55°4′S, 67°40′W), southern Chile. We found no statistical support for a relationship between variation in paternal care and the percentage of extra‐pair offspring. We discuss how the inability of breeding males to assess their genetic paternity and potential restrictions on behavioral flexibility may explain this result. Additionally, if paternal care is subjected to sexual selection, this could limit a facultative response to female extra‐pair behavior by males. Finally, it is possible that a reduction in paternal care might not have evolved in this particular locality given the low frequency of extra‐pair paternity in our study population.

The study deals with the San Juan farmstead near the town of La Unión in southern Chile. It was owned by R. A. Philippi, who was among the first generation of German colonists to settle in the southern territories of Chile. The management of the farmstead's affairs was entrusted to custodians, and Julius Böhlendorf, the husband of Philippi's daughter Ella, held this position from the 1870s. The Böhlendorfs lived on the estate for almost thirty years and managed its everyday operations. This study focuses on the period between the 1860s and the 1880s and the text is based on a thorough study and interpretation of archive records, particularly the diaries and letters of members of the Philippi and Böhlendorf families (stored in the Dirección Museológica de la Universidad Austral de Chile archive in Valdivia). The main aim of the work is to present and give a sense of the functioning of the farmstead and to show its structure and the kinds of work done there. [ABSTRACT FROM AUTHOR]

Organism biomass, a continuous quantity, may be useful for general community and diversity assessment. Body length and biomass of benthic macroinvertebrates from two aquatic environments with different impact levels are determined in this study, classifying organisms using functional and taxonomic characteristics. Lyophilized benthic macroinvertebrate biomass was quantified to test for significant differences between an impacted and reference (less environmental impact) site. Results show that macroinvertebrate assemblages from the less impacted stream had higher average biomass than the assemblage from the perturbed site, and significant differences in biomass of Plecoptera, Trichoptera, predators, filterers and gills breathers were found between sites. The biomass signature was calculated for each analyzed scenario, weighting the presence of all specimens sampled considering the total biomass in a single regression curve equation. The cubic polynomial model had the best fit to the data. More background from theory to practice should be considered in biomonitoring research; hence we propose the application of macroinvertebrate biomass as an additional metric that will help evaluate the ecological status of streams, thus contributing to the knowledge of community-based biomonitoring of benthic macroinvertebrates. [ABSTRACT FROM AUTHOR]

Ecological interactions among multiple invaders can aggravate their effects on invaded systems. Many salmonids including rainbow trout Oncorhynchus mykiss and Chinook salmon O. tshawytscha have established naturalized populations and co-occur in rivers worldwide. Predation of eggs and juveniles has been well documented among salmonids in their native range in the Northern Hemisphere. It has been unclear to what extent these interactions exist in invaded rivers of the Patagonia. Here, we report and quantify rainbow trout predation of Chinook salmon eggs in the Cisnes River Basin, southern Chile. We used hook and line angling to sample rainbow trout (n = 80) around salmon spawning areas before, during, and after the spawning season of Chinook salmon. Stomach contents obtained during two consecutive years show consistent evidence that rainbow trout opportunistically prey on Chinook salmon eggs. Salmon eggs occurred in 75 and 50% of the trout stomachs analyzed in 2019 and 2020, respectively. The number of salmon eggs (mean ± SD) per trout stomach ranged between 17.95 ± 24.29 in 2019 and 7.45 ± 12.90 in 2020. We assumed that consumed eggs were primarily non-viable or would have had low probabilities of survival suggesting a synergistic interaction between rainbow trout and Chinook salmon. Our findings provide baseline information that contribute to demographic studies and the management of invasive salmonids in rivers of this region and elsewhere. [ABSTRACT FROM AUTHOR]

Since the 1980s, forest plantations have expanded globally in response to commercial demand for wood products. Research has focused mainly on the economic and environmental impacts (carbon reduction) of the forestry industry. However, our research focuses on the social impact of large-scale forestry plantations, particularly the effect of the expansion of tree plantations on local communities. We evaluate the positive (employment and income) and negative (poverty and income inequality) externalities of the expansion of the forestry industry in Indigenous and non-Indigenous populations located in six regions of Southern Chile, where 73% of the rural Indigenous people live, over the period 1997–2015. Our findings show that the forestry industry's expansion has not reduced unemployment or improved incomes for the Indigenous or non-Indigenous population. On the contrary, it has increased poverty and inequality between them. [ABSTRACT FROM AUTHOR]

Bridging remote-sensing ecosystem indices with biodiversity conservation implies converting these indices into habitat quality indicators for species playing an important role in communities and ecosystems, such as woodpeckers. However, an ecologically reliable estimation of habitat quality necessarily involves an assessment of fitness components ultimately responsible for population persistence. Here, we assessed the relationship between remote-sensing indices of forest structure, dynamics and composition with the breeding performance of Magellanic woodpeckers in conservation areas of southern Chile. We used a Bayesian-spatial model based on age and sex information from woodpecker’s social group data collected seasonally in seven years. The probability of a young remaining in the group decreased with the mean group size during the previous year, with group size fluctuating temporally in all conservation areas. Tree senescence had a positive effect on the pairing probability of woodpeckers, but this effect became more marked in sites of higher altitude. Paired woodpeckers were more likely to be observed in sites supporting more than 69% of forest cover. The probability of the young remaining in the territory was positively affected by the interaction between forest canopy continuity and altitude, with retention of the young being more likely in sites located higher than 1000 masl. Social groups were larger in sites where the continuity of canopy increased over time. Those findings suggest that remote sensing indices representing the structure and dynamics of forest ecosystems are important indicators of the habitat quality for woodpeckers. Thus, forest biodiversity that depends on the woodpecker's engineering function may be conserved through the retention of senescent trees and the maintaining of critical levels of forest cover ensuring high habitat-quality for breeding woodpeckers.

We present an interpretation of how natural geological and meteorological events influenced the cosmovision of the Mapuche people from south-central Chile. These events resulted from the geodynamic conditions and related processes occurring along the South American active continental margin and the climatic conditions in the region. Their influence on the Mapuche cosmovision is clearly reflected in the most important myths and legends of the Mapuche acquired knowledge. One particularly illustrative myth refers to the combat between two huge snakes, Trentrén and Kaikai. Kaikai, representing the ocean, continuously tries to encroach upon the earth, and Trenten, representing the earth, opposes Kaikai by uplifting the ground to save the inhabitants. This is interpreted as an allegory for what happens during earthquakes when the back-and-forth movement of tsunami waves makes it appear as if the earth sinks and uplifts. Several hills named Trentrén are topographic heights that people can climb to be safe from the effects of the tsunamis. Other myths and legends refer to other characteristic geological phenomena in this particularly active tectonic environment. This article illustrates how the mythical interpretation of geological events configured the understanding of the surrounding world and produced the exquisite body of myths and legends in the Mapuche culture. [ABSTRACT FROM AUTHOR]

Chile has a large number of wetlands that offer a wide variety of refuges and food to waterbird assemblages. This research hypothesises that these assemblages differ according to the structural characteristics of each type of inland wetland. The object is to identify the structure of these assemblages, evaluating their richness, alpha α diversity and some ecological characteristics, taxonomic structures and trophic guilds. We performed a meta-analysis by submitting pre-selected articles to multivariate reliability analysis. The selected articles were used to characterise the assemblages by alpha α diversity: species richness, Shannon-Wiener index, Pielou's Evenness Index, relative abundance and taxonomic distinctiveness Δ + and beta β diversity: Bray-Curtis with analysis of similarity percentage. Diversity and evenness differed in the seven wetlands studied, among 12 to 45 species, Shannon-Wiener index H'= 0.08 to 0.94 bits and Pielou's Evenness Index J'= 0.06 to 0.71. Four wetlands were below and three above the expected value for taxonomic distinctiveness (Δ +) (73.2 units). Two clusters were identified using the β diversity: one consisting of the High-Andean wetlands (Huasco and Negro Francisco); and the other of El Peral lagoon, the Cruces River wetlands complex and the Tranque San Rafael man-made wetland. The most remarkable dissimilarity was provided by three species (Cygnus melancoryphus, Phoenicoparrus jamesi and Phoenicoparrus andinus). Zoophagous species that eat invertebrates by the first choice are the dominant group, while in lagoon wetlands phytophages and omnivores are more evenly represented. [ABSTRACT FROM AUTHOR]

Within‐population variation in timing of breeding may be linked to a trade‐off between the risks and benefits of breeding earlier. This trade‐off may be mediated by individual risk‐taking behaviour, but this needs to be assessed in detail in wild populations. Here, we recorded timing of breeding and risk‐taking behaviour during three consecutive breeding seasons in a resident population of Thorn‐tailed Rayadito Aphrastura spinicauda located in Navarino Island (55°S), southern Chile. Navarino is a high‐latitude, highly seasonal continental island in southern Chile where early breeding may be risky for rayaditos, given the presence of low temperatures, storms and relatively low food abundance during early spring. We used novel environment tests to assess exploratory behaviour, which in turn was used as a proxy of risk‐taking behaviour. In addition, we evaluated the potential consequences of timing of breeding and risk‐taking behaviour on three measures of reproductive success: clutch size, number of fledglings produced and body condition of the offspring. We found that risk‐prone individuals started breeding earlier than risk‐averse individuals but we did not find evidence for an effect of timing of breeding on any of the variables of seasonal breeding success. However, we observed that fast‐exploring females tended to lay smaller clutches. Measurements reflecting lifetime reproductive success may better reflect an effect of timing of breeding and risk‐taking behaviour, but this needs to be studied. Our results support the idea that risk‐taking behaviour is linked to early breeding in high‐latitude environments. We suggest that, despite the risks that low temperatures and snowstorms pose to breeding rayaditos during early spring, it is possible that early breeders increase the probability of occupying better nesting cavities and they may adjust the timing of breeding to match brood provisioning with peak resource abundance. [ABSTRACT FROM AUTHOR]

Data collected between 2015 and 2022 was utilised to assess longitudinal connectivity and explain the temporal and spatial fluctuation of large wood (LW) along the Blanco River, which was severely affected by the 2008 eruption of the Chaitén Volcano in southern Chile. The study was performed along a ~ 10.6-km long segment, which was divided into two sub-segments (upper and lower). LW source areas were identified using information from previous research, complemented by the analysis of satellite images to cover the study period. LW fluctuation was studied for the period 2017–2022, using field data and images from an unmanned aerial vehicle along seven 80 m-long reaches located within the lower sub-segment of the river. Using the generated georeferenced orthomosaics and digital elevation models, LW and wood jams (WJs) locations, abundance, dimensions, volumes, and WJs stability were assessed, as well as wood deposition patterns. Streambank erosions and landslides were found to be the main LW sources. Considering wood sourcing, and the variations in the number of LW and WJs, in the dimensions of individual LW and WJs volume and deposition patterns as indicators, it was possible to infer the longitudinal connectivity conditions for the studied segment through time. The results showed that the upper and lower subsegments were poorly connected. However, changes in LW abundance over time, its dimensions and volumes, and the very low stability of WJs, and LW deposition patterns indicative of fluvial transport confirmed that the lower subsegment was longitudinally connected. The results also verified that the presence of LW did not affect water or sediment longitudinal connectivity along the fluvial system. The volume of individual LW and WJs showed a decreasing trend with time in all study reaches. As the bank erosions able to source LW to the channel are also reducing with time, pieces of wood deposited in the active channel may become the only way to sustain LW availability for the next few years. Things could change with the occurrence of an extreme and infrequent flood able to connect the upper and lower sub-segments and force the river to initiate a new phase of planform adjustments. [Display omitted] • Large wood (LW) was studied in a river affected by a volcanic eruption. • LW volume decreased from upstream to downstream and with time since the eruption. • Different degrees of connectivity were derived from a semi-quantitative approach. • LW is not affecting longitudinal water and sediment connectivity along the river. [ABSTRACT FROM AUTHOR]

Abstract Woodpeckers can be difficult to detect, as they are often cryptic, secretive, occurring in low densities, and wary of humans. Several methods exist to detect woodpeckers (e.g., playback surveys, passive point counts), yet no research has established which technique best detects these elusive picids. Thus, we designed an experiment to determine which of three methods best results in a detection of Magellanic Woodpeckers (Campephilus magellanicus), and if weather variables influence detection probability. Mostly during austral summers 2015–2017, we (a) used a drumming device to simulate a double‐knock (i.e., territorial acoustical signal), (b) broadcasted a territorial call, and (c) passively listened (control) for Magellanic Woodpeckers. We conducted our experiment on Navarino Island, Chile, where the Magellanic Woodpecker is the sole picid. The drumming device most effectively influenced the likelihood of a woodpecker detection. The odds of a woodpecker responding to a double‐knock were 2.14 times more likely than responding to either a call or control. Moreover, the odds of a woodpecker detection decreased by 42% as wind increased by one category and decreased by 40% for every additional month (i.e., October–March), which was expected because woodpeckers become less territorial as the breeding season progresses. As Campephilus woodpeckers communicate via drums or double‐knocks, using a drumming device likely will be an effective technique to detect not only Magellanic Woodpeckers, but other woodpeckers within the Campephilus genus in Central and South America.

Fingerprinting techniques were incorporated into a paired catchment investigation in southern Chile to quantify the contribution of three fine sediment sources (catchment surfaces, forest roads and stream channels) to catchment suspended sediment yields during forest harvesting and replanting operations. Optimum composite fingerprints for use in sediment source discrimination and apportionment comprised 137Cs and 210Pbex for the control catchment (LUC) throughout the study and for the treatment catchment (LUT) during the pre-harvest period, and 137Cs and soil organic matter during harvest and post-harvest periods for LUT. Prior to harvesting, the dominant sediment source to the sediment load in both catchments was the stream channel and remained relatively constant throughout the study for LUC. For the entire study period the total suspended sediment yield from LUT (3,160 kg ha-1) approximately doubled that from LUC (1,650 kg ha-1). Most of this difference is accounted for by the increase in sediment output during the rainy months following clearcutting. The disturbance associated with forest operations in LUT caused the contributions to the load from the catchment slopes and forest roads to increase markedly (total contributions 835 and 795 kg ha-1, respectively). However, the total contribution from the stream channel for LUT during the study period (1,530 kg ha-1) remained similar to that from LUC. The results of the investigation demonstrated that any attempt to reduce sediment loading from forest harvesting would require adopting best management practices to reduce sediment mobilization from catchment surfaces and forest roads. [ABSTRACT FROM AUTHOR]

Extra‐pair behavior is present in 76% of socially monogamous bird species with biparental care. This behavior may produce costs to females related to a reduction in paternal care. We estimated the percentage of extra‐pair offspring and quantified paternal care in 44 nests of Thorn‐tailed Rayadito (Aphrastura spinicauda) to assess whether males reduce their parental care when females obtain extra‐pair fertilizations. We used data from a sub‐Antarctic population of Rayadito located on Navarino Island (55°4′S, 67°40′W), southern Chile. We found no statistical support for a relationship between variation in paternal care and the percentage of extra‐pair offspring. We discuss how the inability of breeding males to assess their genetic paternity and potential restrictions on behavioral flexibility may explain this result. Additionally, if paternal care is subjected to sexual selection, this could limit a facultative response to female extra‐pair behavior by males. Finally, it is possible that a reduction in paternal care might not have evolved in this particular locality given the low frequency of extra‐pair paternity in our study population. [ABSTRACT FROM AUTHOR]

The effects of a sudden rainfall (40 mm d-1) event on the surface waters covering muddy tidal flats were studied during April 2016 at the estuarine Cruces River wetland in south-central Chile (~40°S). The study area included flooded vestigial tree trunks, which is evidence of coseismic subsidence associated with the 1960 Valdivia earthquake as a source of environmental variability. The tidal flat with vestigial tree trunks registered the fastest and highest depth of inundation. In contrast, the tidal currents velocity and total suspended solids' concentrations were higher at the flat without trunks. Sudden rainfall events can significantly modify the characteristics of surface waters above sedimentary intertidal surfaces, where structures such as flooded trunks are present. [ABSTRACT FROM AUTHOR]

The intermediate-sized cities of southern Chile experience days of high pollution levels every winter due to the use of wood-burning stoves. Several studies have analysed the factors that hinder energy transition and the social acceptance of measures to improve air quality, the consequences of which are disturbing. However, they have mainly focused on health issues without considering the social impacts of air pollution. This study aims to assess whether exposure to outdoor air pollution is associated with school absenteeism. We analysed the records of approx. 5,000 students in the fourth grade from 25 schools in five cities in southern Chile (2010–2017). Using a fixed-effects model and applying it to the school level, we were able to estimate the effect of air pollution on absenteeism from school after controlling for the effects of individual characteristics. Previous studies have found that independent of air pollution, students from low-income families have a higher absenteeism rate. Our findings suggest that as air pollution worsens, pupils from middle and high-income households are also more likely to miss school days. We argue that this is, presumably, because high-income families are able to develop protective behaviour such as bringing their children to the doctor or keeping them at home on highly polluted days. [ABSTRACT FROM AUTHOR]

Rhipicephalus sanguineus is a species complex with a challenging diagnosis. There are two main lineages: a temperate lineage—now recognized as R. sanguineus sensu stricto (s.s.)—and a tropical lineage. In the Americas, several studies examined the distribution of both lineages. Meanwhile, in Chile, the distribution of the tropical lineage was reported from 18° to 22° S and R. sanguineus s.s. from 20° to 33° S; the morphological diagnosis located R. sanguineus in south-central Chile. In this study, we assessed the morphological and genetic identity of ticks collected from 47 dogs in southern Chile. Six dogs (12.8%) were parasitized by ticks that were morphologically and genetically assigned to R. sanguineus s.s. This finding would represent the southernmost record of this species in the country, located at over 308 km further south than the previous record, suggesting a latitudinal expansion of its distribution. Experimental studies are further required to understand how this tick survives extreme weather conditions when compared to other R. sanguineus s.s. from lesser latitudes. [ABSTRACT FROM AUTHOR]

Peatlands are recognized as crucial greenhouse gas sources and sinks and have been extensively studied. Their emissions exhibit high spatial heterogeneity when measured on site using flux chambers. However, the mechanism by which this spatial variability behaves on a very fine scale remains unclear. This study investigates the fine-scale spatial variability of greenhouse gas emissions from a subantarctic Sphagnum peatland bog. Using a recently developed skirt chamber, methane emissions and ecosystem respiration (as carbon dioxide) were measured at a submeter scale resolution, at five specific 3 × 3 m plots, which were examined across the site throughout a single campaign during the Austral summer season. The results indicated that methane fluxes were significantly less homogeneously distributed compared with ecosystem respiration. Furthermore, we established that the spatial variation scale, i.e., the minimum spatial domain over which notable changes in methane emissions and ecosystem respiration occur, was <0.56 m 2 . Factors such as ground height relative to the water table and vegetation coverage were analyzed. It was observed that Tetroncium magellanicum exhibited a notable correlation with higher methane fluxes, likely because of the aerenchymatous nature of this species, facilitating gas transport. This study advances understanding of gas exchange patterns in peatlands but also emphasizes the need for further efforts for characterizing spatial dynamics at a very fine scale for precise greenhouse gas budget assessment.

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chondrocranial and hyobranchial structure in two South American suctorial tadpoles of the genus Telmatobufo (Anura: Calyptocephalellidae). The chondrocranium, hyobranchium, rectus abdominis muscle, and epaxial musculature of Telmatobufo australis and T. ignotus are described. In addition, these structures were compared wih those of the non-suctorial Calyptocephalella gayi, the sister group of Telmatobufo.

This paper examines theoretical issues surrounding how conservation efforts are reproduced within contemporary capitalism drawing on two cases: Brazil’s eastern Amazon and the forested regions of southern Chile. Drawing on a critical approach to analyze the data from the respective cases, we analyze the ways in which conservation efforts have been territorialized and loaded with symbolism and diversity, which express different ideological geographies. We argue that in the contemporary crisis of capitalism (which has been misunderstood by many observers as an environmental crisis), an array of new commodities have emerged. These processes of commodification have been marked by the commodification of “environmental services” and the creation of more private nature reserves creating value in new ways marked by scarcity and unique natural attractions.

This study describes the cephalic sensory canal pores of the Patagonian toothfish's juvenile and adult specimens (Dissostichus eleginoides) from southern Chile. Specimens exhibited four supraorbital, eight infraorbital, and five mandibular pores, followed by six preoperculars, one coronal pore, one supratemporal pore, and four temporal pores. Juveniles exhibited circular pores in the mandibular, infraorbital, and preopercular region. The first two supraorbital pores are circular, the third is rectangular, and the fourth triangular. The coronal pore is circular with a bifurcation; the supratemporal pore is rectangular. In adults, the first mandibular canal pore is circular, and the last four are elongated. The preopercular canal pores are elongated. The two first supraorbital canal pores are circular, unlike the third and fourth, which are rectangular. The coronal pore is rectangular without bifurcation, and the supratemporal pore has a T-shape. The jaw of juveniles does not present all mandibular canal pores; in the infraorbital region, the first five pores extend as a thin canaliculus, while the adjacent pores appear as longer canaliculi in adults. The differences could be related to changes in spatial distribution during larval, juvenile, and adult stages. Adult cephalic sensory canal pores may have an important role in detecting vibratory waves allowing them to capture their prey and perceive potential predators. Our results provide information regarding the cephalic sensory canal pores of the Patagonian toothfish that may stimulate future studies of this species' mechanosensory system. [ABSTRACT FROM AUTHOR]

The cosmopolitan red alga Callophyllis variegata is harvested and exported as food to Asian countries. In anticipation of overexploitation problems, this study aimed to describe temporal changes in their population structures and chemical composition by comparing intact (Pichicuyén) and exploited populations (San Antonio) of southern Chile, by using linear mixed models. Abundance parameters and size classes were higher in summer months, whereas fertile stages tetrasporophytes and carposporophytes were more abundant in autumn–winter periods. Recruitment was plentiful toward late winter–spring months. Geographical differences were also detected, and San Antonio (C. variegata-exploited) stocks exhibited lower productivity but similar cover/density in comparison to Pichicuyen (intact location). Likewise, this population showed a size structure toward smaller individuals (e.g., recruits) and more sterile individuals than Pichicuyen. Phosphorous, protein, lipid, soluble carbohydrate, and fiber composition also showed a clear seasonal trend, but no differences between localities were found for lipids and soluble carbohydrates. Since C. variegata showed good productivity and interesting nutritional value, we concluded this species shows potential for exploitation and commercialization in southern Chile, as long as specific management protocols and market studies are developed. [ABSTRACT FROM AUTHOR]

The eco‐hydrogeomorphic significance of large wood (LW) and its potential for increasing downstream hazards during extreme floods have been widely recognized. We used LW data collected for a 10‐year period from the two low‐order streams of Pichún (Pi) and Vuelta de Zorra (VZ) in Southern Chile to (a) determine if the abundance and dimensions of individual LW pieces change with time, (b) quantify wood load fluctuations during the 10‐year period, and (c) assess the role of LW recruitment from the riparian forests to explain wood load fluctuations during the study period. Nine years after the first survey, the number of LW pieces in Pi and VZ diminished by 60 and 40%, respectively. Despite the reduction in these numbers, in Pi, the LW dimensions did not change significantly during the study. In VZ, the dimensions exhibited statistically significant differences, despite being within the same class. In both catchments, the LW load fluctuated during a 10‐year period, but the drivers of change differed. Although tree toppling was the recruitment mechanism responsible for LW in both stream cases, the high wood load measured in Pi at the beginning of the study suggested massive tree recruitments before the first survey, followed by wood exports which were higher than inputs in the subsequent 10‐year period. In VZ, LW load decreased during the first 9 years (mean annual rate of ~9.2 m3 year−1) and then increased by ~12.1 m3 year−1 in year 10. At VZ, the inputs consisted of single trees that were recruited from the riparian area and by upstream flotation, while exports occurred by downstream fluvial transport. Wood inputs and exports occurred asynchronously and led to LW load fluctuations at decadal and annual intervals. Land management and tree species thus exert a major influence on wood inventory and budget in streams. © 2020 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Globally, Indigenous Marine Areas are contributing to ocean sustainability by protecting key habitats and species whilst safeguarding customary uses for local communities. They are emerging as one of the key political mechanisms that can counteract the ravages of the blue Anthropocene. Nevertheless, their contributions are threatened by the accelerating expansion of economic activities, and exclusionary marine governance systems, affecting both marine biodiversity and human wellbeing. In southern Chile, indigenous communities have been countering the expansion of the salmon farms by promoting the establishment of Espacios Costeros Marinos para Pueblos Originarios (here called Indigenous Marine Areas or IMAs). These IMAs are being developed by coastal communities to protect traditional or customary coastal uses, and revitalizing culture whilst contributing to marine conservation. Using a relational theoretical approach and mixed methods, the paper presents the major trends in the implementation of IMAs in Chile. Through the case of the Los Lagos Region, it shows how the action-network that pursued the designation of IMAs is continuing today. The paper stresses the role of conservation assemblages to lead collective actions, showing how these constellations of agents have been interacting during the decision-making process and institutional building, whilst promoting the establishment of IMAs as place-based democratic mechanism to promote the sustainability of the southern Chile. [ABSTRACT FROM AUTHOR]

In this paper we present and assess human isotopic data (δ13C and δ15N) available for Southern Chile. We analyze 24 cases from six different geographical zones, dated 200-1850 AD. This new information allows us to characterize individuals who had different subsistence patterns, social organization and historical trajectories, vis-a-vis phenomena like the adoption of ceramics (150 BC), cultigens (750-1000 AD) and the arrival of Europeans (1550 AD). This is complemented by a regional baseline of 45 archaeological faunal and plant resources. Based on our results, three dietary patterns can be identified over time (from 1000 to 1850 AD): one oriented towards marine resources, another towards C 3 plants and terrestrial protein, and the last focused on a mixed consumption of C 3 and C 4 plants, complemented by intake of terrestrial and marine protein. These cases show significant intra-zone consistency over time, and high inter-zone variability. This heterogeneous situation is evident even in synchronous individuals ascribed to the same cultural-historical unit or inhabiting the same geographical macro-zone (valley, coast, islands). It also contrasts with results from adjacent areas to Southern Chile. This highlights the complex diet variability that existed in societies which otherwise appear to be extremely alike in their archaeological record (burials, pottery) and ethnographic features (language, rituals). [ABSTRACT FROM AUTHOR]

Copyright of Boletín del Museo Chileno de Arte Precolombino is the property of Museo Chileno de Arte Precolombino and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background The study of altitudinal gradients provides insights about species diversity, distribution patterns and related drivers. The Magellanic sub-Antarctic ecoregion has a steep elevational gradient, peaking at around 1,000 m a.s.l., and marked changes in temperature and landscape composition can be observed over relatively short distances. Methods This study assessed freshwater macroinvertebrate diversity associated with lakes and ponds along the altitudinal gradient of a Magellanic sub-Antarctic watershed. Results A monotonic decline in species richness was observed with increasing elevation, with simpler and more even community composition at higher altitude. This pattern differs from the mid-peak trend found in streams of the same watershed. Functional feeding group structure also diminished with increasing elevation. Discussion The study provides a descriptive baseline of macroinvertebrate community structure associated with lentic freshwater ecosystems in the Magellanic sub-Antarctic ecoregion, and confirms that elevation has substantial effects on community structure, function and environmental features, even in these relatively low elevation mountain ranges. The harsh environmental conditions of this ecoregion increase freshwater macroinvertebrate development time, as well as decreasing habitat availability and food supply, supporting simple but well adapted communities. In conjunction with previous research, this study provides a watershed-scale platform of information underpinning future long-term research in the region.

The Puelo and Petrohué rivers were surveyed between April 2016 and February 2017 to assess the presence and seasonal abundance of Didymosphenia geminata in the wild aquatic systems of these two important rivers in southern Chile. Didymo was reported in the Puelo River in 2012, while it was declared absent from the Petrohué River before this study commenced in the fall of 2016. Results showed that cells of D. geminata were recorded in both rivers, in the Phytobenthos as well as in the water column. However, the classical mucilage which characterizes this plague was only recorded in one of the sampled rivers (Puelo). The mucilage was not recorded in any of the sections sampled in the Petrohué River, which was attributed to the high concentration of phosphorous present in the system. The concentration of phosphorous recorded throughout the study in the Puelo River was low. However, differences in the recorded presence or absence of D. geminata between sampling sites on the Petrohué River was mainly attributable to the availability of incident sunlight. This study records for the first time the presence of D. geminata in the Petrohué River. [ABSTRACT FROM AUTHOR]

Woodpeckers can be difficult to detect, as they are often cryptic, secretive, occurring in low densities, and wary of humans. Several methods exist to detect woodpeckers (e.g., playback surveys, passive point counts), yet no research has established which technique best detects these elusive picids. Thus, we designed an experiment to determine which of three methods best results in a detection of Magellanic Woodpeckers (Campephilus magellanicus), and if weather variables influence detection probability.Mostly during austral summers 2015–2017, we (a) used a drumming device to simulate a double‐knock (i.e., territorial acoustical signal), (b) broadcasted a territorial call, and (c) passively listened (control) for Magellanic Woodpeckers. We conducted our experiment on Navarino Island, Chile, where the Magellanic Woodpecker is the sole picid.The drumming device most effectively influenced the likelihood of a woodpecker detection. The odds of a woodpecker responding to a double‐knock were 2.14 times more likely than responding to either a call or control. Moreover, the odds of a woodpecker detection decreased by 42% as wind increased by one category and decreased by 40% for every additional month (i.e., October–March), which was expected because woodpeckers become less territorial as the breeding season progresses.As Campephilus woodpeckers communicate via drums or double‐knocks, using a drumming device likely will be an effective technique to detect not only Magellanic Woodpeckers, but other woodpeckers within the Campephilus genus in Central and South America. [ABSTRACT FROM AUTHOR]