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One of the negative effects of linear infrastructures is the formation of barriers to the movements for arboreal wildlife resulting in the reduction in connectivity between populations and thus increasing the risk of extinction. One of the most widely used ways to mitigate these barrier effects is canopy bridges. There is a lack of knowledge about how behavioral differences between species may affect the efficacy of canopy bridges. The purpose of this study was to evaluate the hypothesis that Leontopithecus rosalia (an endangered endemic species) and Callithrix spp. hybrids (introduced invasive species) perceive canopy bridges as sites with risk of predation. We compared the behavior of these species during attempts to cross four canopy bridges installed over oil and gas pipeline right-of-way strips, and another 4 bridges installed inside the forest near the pipeline bridges. The behavior was recorded from 30-second videos obtained from two camera traps installed at each end of the bridges. Of the 1917 crossing events identified, 356 events were randomly chosen for behavioral data collection. Of these, 173 were social group crossing events and 183 individual crossing events. There were few crossings (7.9%) with the two species present. The differences between the species were more quantitative than qualitative and may be related to interspecific differences in vulnerability to predation and anti-predatory tactics. Both species exhibited significantly more behaviors related to perception of risk of predation (vigilance, hesitation, rapid passage) in the pipeline bridges than in the forest bridges. One vigilance measure showed higher occurrence during the first months after installation of the cameras, especially for Callithrix spp., but in general there was little waning of the risk-assessment response. Alarm calls, scent marking and social and feeding behaviors were rare or absent. Low-cost simple canopy bridges may be an effective strategy to overcome the barrier effect of right-of-way strips over gas and oil pipelines. However, the results on perceived risk of predation raise the hypothesis that there may be a cost-benefit ratio between distance to be traveled and risk perception that would lead to a reduction in effectiveness of bridges in greater distance. We discuss the implications for conservation of an endangered species and management of an invasive species. [ABSTRACT FROM AUTHOR]

The first step towards understanding the conservation situation and informing conservation decision‐making is to identify the habitat loss drivers. However, for nearly all tropical biota, there is a glaring lack of information on the spatiotemporal patterns of anthropogenic drivers.Our objective was to analyse the spatial and temporal distribution of the main anthropogenic drivers of habitat loss for Bradypus torquatus and Bradypus crinitus, two endangered and endemic species to the Brazilian Atlantic Forest.We used land‐use information associated with seven major IUCN‐based threats to sloths, covering a three‐generation time window (1988–2020), to quantify the current area occupied, temporal changes, heterogeneity, and intensity of drivers across species distributions.We found that cattle farming and ranching dominate the range of both species (from 49% to 56%) and cover an area larger than the remaining native forest. Other drivers also represent important spatial and temporal features of land conversion across species distributions.Driven mainly by livestock expansion, both sloth species have experienced a significant loss of forest cover (Bradypus torquatus – 659098.70 ha; Bradypus crinitus – 139013.20 ha) in the Brazilian Atlantic forest. Overall, Bradypus torquatus showed a higher rate of deforestation than forest regeneration, whereas forest gains outweighed habitat loss for Bradypus crinitus.Our results show that a substantial area of native forest – essential for strictly arboreal species – is being continuously replaced by cattle ranching and agricultural activities, which may lead to population isolation and decline, threatening the long‐term population viability. [ABSTRACT FROM AUTHOR]

One of the negative effects of linear infrastructures is the formation of barriers to the movements for arboreal wildlife resulting in the reduction in connectivity between populations and thus increasing the risk of extinction. One of the most widely used ways to mitigate these barrier effects is canopy bridges. There is a lack of knowledge about how behavioral differences between species may affect the efficacy of canopy bridges. The purpose of this study was to evaluate the hypothesis that Leontopithecus rosalia (an endangered endemic species) and Callithrix spp. hybrids (introduced invasive species) perceive canopy bridges as sites with risk of predation. We compared the behavior of these species during attempts to cross four canopy bridges installed over oil and gas pipeline right-of-way strips, and another 4 bridges installed inside the forest near the pipeline bridges. The behavior was recorded from 30-second videos obtained from two camera traps installed at each end of the bridges. Of the 1917 crossing events identified, 356 events were randomly chosen for behavioral data collection. Of these, 173 were social group crossing events and 183 individual crossing events. There were few crossings (7.9%) with the two species present. The differences between the species were more quantitative than qualitative and may be related to interspecific differences in vulnerability to predation and anti-predatory tactics. Both species exhibited significantly more behaviors related to perception of risk of predation (vigilance, hesitation, rapid passage) in the pipeline bridges than in the forest bridges. One vigilance measure showed higher occurrence during the first months after installation of the cameras, especially for Callithrix spp., but in general there was little waning of the risk-assessment response. Alarm calls, scent marking and social and feeding behaviors were rare or absent. Low-cost simple canopy bridges may be an effective strategy to overcome the barrier effect of right-of-way strips over gas and oil pipelines. However, the results on perceived risk of predation raise the hypothesis that there may be a cost-benefit ratio between distance to be traveled and risk perception that would lead to a reduction in effectiveness of bridges in greater distance. We discuss the implications for conservation of an endangered species and management of an invasive species.

Beach and sun tourism in the Colombian Caribbean is an extremely important activity that leads to social practices that generate recreational and economic activities directly impacting the environment. The research focuses on assessing the sensitivity to the loss of beaches as tourist resources in four locations within the Colombian Caribbean (Santa Verónica, Salinas del Rey, Bocatocino, and Las Arenas). The sensitivity indicator was developed using GIS to process variables such as the width of the usable beach, the presence of dunes, and rates of coastal erosion spanning from 2003 to 2019. Additionally, anthropic occupation was examined through satellite images. The results allowed for identifying vulnerability indices and recognizing the critical role of dunes in beach preservation. The study revealed that the analyzed beaches exhibited varying degrees of sensitivity. Notably, historical erosion rates and dunes were the most influential variables affecting sensitivity. In conclusion, understanding the sensitivity state concerning the loss of beach areas as tourist resources helps delineate stable sectors and those more susceptible to erosion processes. This knowledge proves invaluable in prioritizing the design and implementation of protective measures in areas requiring urgent attention. [ABSTRACT FROM AUTHOR]

Copyright of Caldasia is the property of Universidad Nacional de Colombia 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.)

The persistence of species in fragmented landscapes relies on landscape connectivity and individuals' ability in dispersing among habitat patches. Accordingly, matrix structure can affect the orientation of dispersing individuals across the landscape. In this study, we measured the impact of matrix structure on the dispersal performance of the white‐eared opossum (Didelphis albiventris). We released individuals in three types of matrix: bare field, corn crops, and soybean crops, with distances of 30, 50, and 100 m to the nearest habitat patch. To test if the release height would affect the individuals' dispersal performance, we released animals from the ground and from 2‐m‐high platforms. We released and tracked 14 individuals in bare field on the ground; 30 in corn crops, 22 on the ground, and 8 on platforms; 17 on soybeans crop, 12 on the ground, and 5 on platforms. The type of matrix influenced the perceptual range. Perceptual range was 100 m in bare field, 50 m in corn field, and <30 m in soybean field. The platforms only increased the perceptual range of individuals in the corn field from 50 to 100 m. Visual and olfactory cues would cause this effect. We conclude that matrix structure affects dispersal performance, and that vertical elements of the matrix, such as scattered trees, may increase orientation in crop fields during inter‐patch dispersal. [ABSTRACT FROM AUTHOR]

Chaetophractus villosus was once distributed from the south of Bolivia and Paraguay to the northwest of Patagonia, where the species survived in glacial refugia during Pleistocene. After the ice retreated, the species expanded its distribution further south reaching Chubut River. In the last two centuries, the species colonized the rest of Patagonia on both sides of the Andes and was introduced in Tierra del Fuego (TDF) in 1982, where it expanded its distribution range along 484 km2 until 2005. A single mitochondrial Control Region haplotype (HC) was described across Argentine Patagonia based on the low number of samples. This lack of variability was exceptional and impressive, taking into account that the northern neighboring areas of distribution are considered ancestral due to the haplotype richness. Here, we added new field and genetic data and compiled recent bibliography to update the biogeography and phylogeography of the species in southern South America. To explain the unprecedent lack of genetic variability, we discussed three main aspects: a historical biogeographic aspect related to the natural barriers for the species, a strong stochastic component, and the possible adaptive advantages of the only mitochondrial lineage detected, whose colonization and acclimatization to the new environment were mediated by man. We also estimated that the current distribution range in TDF is about 8527 km2. [ABSTRACT FROM AUTHOR]

Abstract The bifurcation of a river is a transient condition caused by an avulsion where a channel is abandoned, and a new one is developed. The bifurcation may remain for an extended period. The Mezcalapa River, located in the Grijalva River Basin, in southwestern Mexico, has a record of several avulsions; the last one occurred in 1934 giving origin to the bifurcation Mezcalapa-Samaria-Carrizal that is still active. There have been significant changes in the flow distribution in the bifurcation during the last five decades, with flow distribution ratios oscillating from 0.1, that was attained by 1983 and again in 2017, to ratios of 2 observed by 2004. We utilized historical records of gauging stations, satellite imagery, and field data to characterize the hydraulic and morphologic behavior of the bifurcation. Historical data shows that a system of dams has reduced the sediment yield arriving at the bifurcation since 1966 and that the bifurcation planform is changing constantly. Interventions to control the flow distribution have a considerable impact on the behavior of the bifurcation. Highlights • Bifurcation evolution as a product of avulsion in lowlands during the last 50 years • The bifurcation suffered the effect of four dams located upstream. • The banks are dynamic, with a constant migration process. • The flow distribution has a high sedimentation process in one of the bifurcates. • Changes were correlated with the anthropogenic modifications in the fluvial system. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of human trampling on the benthic macrofauna of two beaches in Southeast Brazil with different levels of intensity of tourism, Grussaí (more impacted) and Manguinhos (less impacted), during periods of high and low tourism activity. The macrofauna of urbanized (U) and non-urbanized ( NU) sectors of the inter-tidal zone was sampled and the number of visitors was recorded. General linear models revealed a decreasing in abundance of macrofauna species in the urbanized sectors of analyzed beaches, which are exposed to higher trampling impact than in non-urbanized areas. At Manguinhos Beach, trampling did not affect the macrofauna (<1 visitors ∙ m−²), except for the polychaete Scolelepis sp., which was less abundant in the U sector. Considering the benthic community, Atlantorchestoidea brasiliensis, Hemipodia californiensis and Scolelepis sp. were more sensitive to human trampling pressure and may be used as potential bioindicators of tourism impact. Management plans should consider mitigation of the effects of tourism, such as the control of the visitor number and their decentralization. [ABSTRACT FROM AUTHOR]

This work presents alterations in the concentrations of alkaline metals sodium, lithium and potassium, in abiotic compartments, at Araçá stream micro-basin, located in Canoas, RS. Its spring is located in a low populational density region and crosses an elevated environmental impacted urban area. Its final course crosses an agricultural area. Samples of atmospheric particulates, macrophites, water and sediments were analyzed. High concentrations of alkaline metals, related with draining of rice fields or with the ground type, as well as correlations among its concentrations with regional activities were verified. Tripogandra diurética has shown bioaccumulation compatible with their concentrations on waters.

Objective. Opossum populations (Didelphismarsupialis) were characterized in an ecotourism area in Santa Elena, district of the city of Medellín and in the periurban and urban areas of the city of Caldas, Antioquia; using phototraps. Materials and methods. 7 Moultrie Game Spy® cameras were placed to determine relative abundance index (RAI) and rotated every three weeks. Baits were used to make observation easier. Results. For the Santa Elena district the sampling effort was 360 days / trap, in which 22 photographs of the species were obtained. Didelphismarsupialis had a total RAI of 0.18; of which 0.06 represented its abundance in the native forest and the remaining value was part of the area with pine trees. For the peri urban zone of the city of Caldas the sampling effort was 679 days / trap. The species Didelphismarsupialis had a total RAI of 0.4; which represents an approximate number of 26 individuals at the Santa Inés practice center. In the urban area of the city of Caldas it was not possible to establish this pattern. Conclusion. The study indicates that despite the transformation of the peri urban area in the Aburrá Valley it is possible to find elements representative of its peri urban mammals, even in small private reserves. The Didelphidae family has adapted to highly modified ecosystems, even in areas with invasive species such as exotic monocultures of exotic species, livestock pastures and anthropic transformation given by the fragmentation of forests, however these marsupials are forced to migrate locally to changes in the microclimate of forest fragments. [ABSTRACT FROM AUTHOR]

Escudero, M.; Silva, R., and Mendoza, E., 2014. Beach erosion driven by natural and human activity at Isla del Carmen Barrier Island, Mexico. The study site is located on the Gulf of Mexico and is part of the most valuable lagoon-estuarine system in Mexico, not only in ecological terms but also as an important economic and social site for the country. Although the current state of the environment is still reasonably healthy over much of its area, the natural equilibrium has been greatly affected by human activities, as in many of other coastal lagoons worldwide ( e.g., infrastructure and building construction, installation of inappropriately designed defense structures, degradation of vegetation and an artificial lagoon opening). The consequence is a sediment deficit that, combined with the impact of tropical cyclones and the absence of an external sand supply, has led to persistent beach erosion. The analysis of the physical settings, historical shoreline changes and hydrodynamic patterns of the study site has helped to identify the critical elements affecting the current state of the beach. This paper proposes a shoreline protection scheme, based on the understanding of the current functioning of the site, in order to reduce local flooding and erosion risks, which affect the population and tourism, and to preserve the natural environmental services of the area. [ABSTRACT FROM AUTHOR]

Martins, K.A. and Pereira, P.S., 2014. Coastal erosion at Pau Amarelo Beach, northeast of Brazil. This article concerns the erosion at Pau Amarelo Beach in Pernambuco, Brazil. The maintenance of this beach is important for tourists and the community and is significant for the local economy. Pau Amarelo is a highly urbanized area with poor coastal plain. The coast is characterized by the presence of lined reefs running along the shore. In order to understand the causes of the erosion at this site, coastline variation, the displacement of urban areas and wave characteristics were analyzed. It is believed that both the human incursions on the backshore and the intensification of longshore currents in some parts of the coast, caused by wave diffraction at the reefs, contribute to the beach erosion. The breakwaters built south of Pau Amarelo are also believed to decrease sediment transport by blocking the drift current. Beach nourishment is suggested as the most suitable solution to the erosion at Pau Amarelo. [ABSTRACT FROM AUTHOR]

Copyright of Neotropical Biology & Conservation is the property of Pensoft Publishers 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.)

Summary: Heat was applied as a tracer for determining river–aquifer relations in the Motril-Salobreña aquifer (S Spain). The aquifer has typically been recharged by River Guadalfeo infiltration, nevertheless from 2005 a dam was constructed changing the traditional dynamic river flow and recharge events. Temperature measurements in river, air, and a number of boreholes located at different distances away from the river were monitored over a 6year period. Temperature is easy to monitor and especially useful in anthropized aquifers due to their natural and non-pollutant characteristics. The thermal responses of recharge events have been analyzed with different methodologies for the characterization of the recharge process. Changes in groundwater temperatures recorded between 15 and 40m deep are detected during the periods of higher river discharge. Temperature logs envelopes reveal areas of infiltration dominance and areas where vertical upward flows are present. For the quantification of the recharge volume, a model was constructed with VS2DHI. The study of the temperature measurements suggests an upper zone of groundwater temperature variability related with the direct infiltration from the river. Also there is a deeper zone where temperature changes are related with the heat transport associated to the main groundwater flow in the aquifer. With the evaluation of the temperature data by different means, the conceptual three-dimensional flow model has been strongly improved establishing the basis for a future 3D modelling. [Copyright &y& Elsevier]