Anthropic Landscape Research Articles

Landscape and meteorological determinants of malaria vectors' presence and abundance in the rural health district of Korhogo, Côte d'Ivoire, 2016-2018, and comparison with the less anthropized area of Diébougou, Burkina Faso.

Understanding how weather and landscape shape the fine-scale distribution and diversity of malaria vectors is crucial for efficient and locally tailored vector control. This study examines the meteorological and landscape determinants of (i) the spatiotemporal distribution (presence and abundance) of the major malaria vectors in the rural region of Korhogo (northern Côte d'Ivoire) and (ii) the differences in vector probability of presence, abundance, and diversity observed between that area and another rural West African region located 300 km away in Diébougou, Burkina Faso. We monitored Anopheles human-biting activity in 28 villages of the Korhogo health district for 18 months (2016 to 2018), and extracted fine-scale environmental variables (meteorological and landscape) from high-resolution satellite imagery. We used a state-of-the-art statistical modeling framework to associate these data and identify environmental determinants of the presence and abundance of malaria vectors in the area. We then compared the results of this analysis with those of a similar, previously published study conducted in the Diébougou area. The spatiotemporal distribution of malaria vectors in the Korhogo area was highly heterogeneous and appeared to be strongly determined and constrained by meteorological conditions. Rice paddies, temporary sites filled by rainfall, rivers and riparian forests appeared to be the larval habitats of Anopheles mosquitoes. As in Diébougou, meteorological conditions (temperatures, rainfall) appeared to significantly affect all developmental stages of the mosquitoes. Additionally, ligneous savannas were associated with lower abundance of malaria vectors. Anopheles species diversity was lower in Korhogo compared to Diébougou, while biting rates were much higher. Our results suggest that these differences may be due to the more anthropized nature of the Korhogo region in comparison to Diébougou (less forested areas, more agricultural land), supporting the hypothesis of higher malaria vector densities and lower mosquito diversity in more anthropized landscapes in rural West Africa. This study offers valuable insights into the landscape and meteorological determinants of the spatiotemporal distribution of malaria vectors in the Korhogo region and, more broadly, in rural west-Africa. The results emphasize the adverse effects of the ongoing landscape anthropization process in the sub-region, including deforestation and agricultural development, on malaria vector control.

Seed dispersal by bats (Chiroptera: Phyllostomidae) and mutualistic networks in a landscape dominated by cocoa in the Brazilian amazon

Bats play essential roles in neotropical ecosystems, performing crucial ecological functions such as insect pest control, pollination of plants with significant economic, social, and ecological value, and seed dispersal, including that of pioneer plant species. These animals are directly linked to human well-being, and declines in their populations can even have adverse effects, such as increasing the need for pesticides in regions where natural insect control is reduced. The seed dispersal conducted by bats is fundamental for maintaining neotropical biodiversity, as it supports habitat regeneration and the propagation of various plant species. Moreover, the role of these dispersers is enhanced due to their ability to inhabit a variety of environments, from natural forests to anthropized areas. However, the conversion of natural forests into agricultural production areas, as well as urbanization, has affected the structure of mutualistic networks between bats and plants. In this context, the objective of this study was to identify the pattern of seed dispersal by bats of the Phyllostomidae family in an anthropized landscape of the Brazilian Amazon. Data collection was conducted in different areas of natural forest, cocoa cultivation, and urban areas in the municipalities of the States of Pará. Regarding the results, the most representative subfamilies of bats were Carollinae (72.15%) and Stenodermatinae (21.8%). The botanical families Piperaceae (35.52%) and Solanaceae (19.71%) were the ones most preferred by the bats. Regarding species richness, the general bat-plant interaction network included 15 botanical families and 26 species of bats. The general interaction network was nested (WNODF= 29.8), with low Specialization (H2=0.27), Connectance (0.17), and Modularity corresponding to M=0.21. Thus, we highlight the importance of these species for the restoration of degraded environments. Therefore, through the execution of projects that demonstrate the importance of chiropterochory in the restoration of degraded ecosystems in the Amazon, it will be possible to create measures and subsidies focused on the conservation of bat and plant species that play a role in maintaining the planet's biodiversity.

Protected area creation and its limited effect on deforestation: Insights from the Kiziba-Baluba hunting domain (DR Congo)

The study examines the spatiotemporal dynamics of landscape anthropization in the Kiziba-Baluba Hunting Domain (KBHD), near Lubumbashi in southeastern Democratic Republic of Congo, facing increasing human threats. It assesses these dynamics from 1989 to 2023 using remote sensing, Geographic Information Systems (GIS), and landscape ecology principles. The results reveal a significant decrease in forest cover, declining from 70.33 % in 1989 to 26.22 % in 2023, with an annual deforestation rate of -1.84 %. This deforestation has led to the expansion of savannas (63.93 %), agriculture (5.76 %), and built-up and bare soil (0.93 %) through patch creation and aggregation. The level of landscape disturbance has increased sixfold over 34 years, from 0.42 in 1989 to 2.81 in 2023. The reduction in the size of the largest forest patch and increased spatial isolation show rising fragmentation and dissection, often followed by the attrition of residual patches. These findings highlight the inefficiency of current conservation measures in KBHD, indicating a need for restructuring management, redefining protected area boundaries, developing a suitable management plan, implementing reforestation programs, strengthening enforcement of environmental laws, and actively involving local communities.

Use of woody species in the Caatinga dry forest may lead to higher vulnerability to extirpation: An assessment based on ethnobiological, reproductive and conservation criteria

Tropical forests play an important role in maintaining, replenishing and conserving a large portion of the planet's biodiversity. However, these forests have been converted into anthropic landscapes, threatening the persistence of wildlife. The exploitation of forest products can result in different ecological impacts at different levels of biological organization. In this study, we propose a vulnerability index to examine the susceptibility of woody plants used by locals in a human-modified landscape of the Caatinga dry forest (i.e., the Catimbau National Park). We contrasted patterns of (1) plant use by local people (risk of use, collection risk, local importance, and diversity of use), (2) plant reproductive strategies (pollination, sexual and reproductive systems, dispersal mode, flowering and fruiting phenology), and (3) the conservation status of the plant species. We combined this information to propose a vulnerability index expressing species sensitivity to human disturbances in 14 regenerating and 14 old-growth forest stands. We tested the hypothesis that regenerating forest stands will harbor more vulnerable plant species compared to old-growth forest stands. Among the 119 plant species registered in regenerating and old-growth forest stands, 80 species (67.2 %) were recorded as useful for local people in Caatinga. Specifically, about 71.8 % and 70.5 % are exploited by the rural population for some type of use in regenerating and old-growth forest stands, respectively. The most frequent type of use was medicinal, followed by construction and fuel in both regenerating and old-growth forest stands. Regarding the potentially collected plant parts, the total removal of the individual and collection of leaves exhibited similar and higher relevance in regenerating, while leaves were the most collected part in old-growth forest stands. Of the 80 plant species analyzed, 62 % and 58.5 %, respectively, were classified as exhibiting moderate and high vulnerability to extirpation in regenerating and old-growth forest stands; thus not supporting our hypothesis. Our results suggest that in the Caatinga dry forest, (1) woody plant species responsible for forest regeneration in the context of slash-and-burn agriculture are exploited for multiple uses, (2) medicinal use is the main type of use of woody plants occurring in regenerating and old-growth forest stands, (3) total removal of the individual and collection of leaves were the most collected plant parts, and (4) both regenerating and old-growth forest stands showed a high vulnerability to human disturbances in the study area. In the long term, the exploitation of vulnerable plant species may negatively affect the composition and structure of the community and, consequently, the rate and trajectory of succession. It can be expected that as populations of vulnerable plant species are reduced or extirpated from the community, ecological interactions such as pollination and dispersal, which are key to ecosystem maintenance, will change along with the services provided.

Missing Landscapes: A Geohistory of Parkland Landscapes in Northwestern Morocco

Northwestern Morocco is characterized by highly anthropized landscapes under the combined effect of agricultural intensification, resource overexploitation, urbanization, and tourism, but also local reforestation. Reconstructing the recent changes in vegetation in the region of the lower valley of the Loukkos river near Larache and their relationship to the settlement history are particularly helpful for understanding the processes at work within the landscape construction. The geohistorical approach combines paleoenvironmental, documentary, and historical data. The last few centuries have seen the emergence of wooded stands, in which cork oaks are a structural element. As forests were retreating, parklands intended for agriculture, agroforestry, and herding, like the Spanish dehesa and Portuguese montado, began to emerge. Nearly all of them have disappeared today, but we can identify their legacy and evaluate their cultural significance through comparing them with their counterparts in the Iberian Peninsula, but also in other areas of Morocco. Their deep historical roots give this landscape an evolving heritage character that is directly linked to the communities’ lifestyles, culture, and history.

Same landscape, different connectivity: contrasting patterns of gene flow in two sympatric ungulates in a mountain area

Comparative landscape genetics studies provide insights on the impact of landscape elements on gene flow patterns of different species inhabiting the same geographic area. We investigated the population genetic structure of two sympatric ungulates, roe deer Capreolus capreolus and Northern chamois Rupicapra rupicapra, in a mountain area of the central Italian Alps (Trentino, northern Italy). A total of 122 chamois and 72 roe deer samples were genotyped by two species-specific panels of 11 polymorphic microsatellite loci and analyzed by aspatial and spatially explicit analyses. While the roe deer population resulted unstructured, a clear population structure was detected in chamois, with two main groups, one inhabiting the eastern and the other spread in the western part of the study area. Landscape genetics analysis confirmed these scenarios and revealed a different effect of landscape on gene flow. An IBD (Isolation-By-Distance) model best explained genetic variation in roe deer, while IBR (Isolation-By-Resistance) was found as the process underlying genetic variation patterns in chamois, suggesting arable lands, coniferous forests, watercourses, and main roads as potential barriers. Species distribution and landscape use might explain these results: roe deer mostly occupy valley floors relatively connected to each other, and their spatial behavior may promote gene flow across areas. On the other hand, chamois prefer higher elevations and their movements may be hindered by valleys, rivers, and road networks. This study highlights the different impacts of natural and anthropic landscape elements on gene flow in two sympatric species, resulting from their different ecological requirements.

Association between environmental gradient of anthropization and phenotypic plasticity in two species of triatomines

BackgroundTriatoma garciabesi and T. guasayana are considered secondary vectors of Trypanosoma cruzi and frequently invade rural houses in central Argentina. Wing and head structures determine the ability of triatomines to disperse. Environmental changes exert selective pressures on populations of both species, promoting changes in these structures that could have consequences for flight dispersal. The aim of this study was to investigate the relationship between a gradient of anthropization and phenotypic plasticity in flight-related traits.MethodsThe research was carried out in Cruz del Eje and Ischilín departments (Córdoba, Argentina) and included 423 individuals of the two species of triatomines. To measure the degree of anthropization, a thematic map was constructed using supervised classification, from which seven landscapes were selected, and nine landscape metrics were extracted and used in a hierarchical analysis. To determine the flight capacity and the invasion of dwellings at different levels of anthropization for both species, entomological indices were calculated. Digital images of the body, head and wings were used to measure linear and geometric morphometric variables related to flight dispersion. One-way ANOVA and canonical variate analysis (CVA) were used to analyze differences in size and shape between levels of anthropization. Procrustes variance of shape was calculated to analyze differences in phenotypic variation in heads and wings.ResultsHierarchical analysis was used to classify the landscapes into three levels of anthropization: high, intermediate and low. The dispersal index for both species yielded similar results across the anthropization gradient. However, in less anthropized landscapes, the density index was higher for T. garciabesi. Additionally, in highly anthropized landscapes, females and males of both species exhibited reduced numbers. Regarding phenotypic changes, the size of body, head and wings of T. garciabesi captured in the most anthropized landscapes was greater than for those captured in less anthropized landscapes. No differences in body size were observed in T. guasayana collected in the different landscapes. However, males from highly anthropized landscapes had smaller heads and wings than those captured in less anthropized landscapes. Both wing and head shapes varied between less and more anthropogenic environments in both species.ConclusionsResults of the study indicate that the flight-dispersal characteristics of T. garciabesi and T. guasayana changed in response to varying degrees of anthropization.Graphical

Riparian habitat connectivity restoration in an anthropized landscape: A multi-species approach based on landscape graph and soil bioengineering structures.

In urbanized areas, rivers and riparian ecosystems are often the only ecological corridors available for wildlife movement. There, riverbanks are often stabilised by civil engineering structures (dykes, riprap). This can lead to habitat degradation and loss of landscape connectivity. Fascines (willow bundles tied together) could be an alternative to riprap, since they maintain the quality of the natural ecosystems by using native vegetal species instead of rocks, but their potential positive impact needs to be assessed. We proposed a landscape-scale decision-making method for river managers who want to restore banks by transforming riprap into fascines to improve landscape connectivity. We applied our methodology to a case study involving a 25 km-stretch of the Arve River, France. We selected four target vertebrate species based on biological traits to cover a wide range of dispersal capacities. For each species, we used landscape graphs to assess habitat connectivity under different contrasted riverbank scenarios. Scenarios included replacing all-natural banks with ripraps or replacing all ripraps with fascines. In addition, we systematically tested the effect of replacing individual 100 or 500 m sections of ripraps by fascines, to locate where riverbank restoration would maximize connectivity gain. The four species selected responded very differently to the scenarios (up to +14% and +46% change in Probability of Connectivity for common toads and Eurasian beavers, respectively, 0% for common sandpipers and barred grass snakes). The restoration of specific riverbank sections could result in important gains in PC (up to +33% for one single section for one species) but no section maximized connectivity gain for all the target species.

New threats in the recovery of large carnivores inhabiting human-modified landscapes: the case of the Cantabrian brown bear (Ursus arctos)

Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears (Ursus arctos) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which—Clostridium novyi and verotoxigenic Escherichia coli—not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population.

Crop phenology reshapes the food‐safety landscape for roe deer in an agroecosystem

Abstract Understanding the behavioural adjustments of wildlife in anthropized landscapes is key for promoting sustainable human–wildlife coexistence. Little is known, however, about how synanthropic species navigate spatio‐temporal variation in the availability of food and cover that are shaped by human practices such as agriculture. Animal habitat use is predominantly driven by spatial and temporal variations in food and cover, as individuals respond to fluctuations in the trade‐off between food acquisition and risk avoidance. In agroecosystems, the availability of high‐quality forage and cover is dependent on agricultural practices (e.g., harvesting) and crop phenology, providing an ideal opportunity to evaluate how wildlife adjust their behaviour in a heterogeneous human‐dominated landscape. We investigated the influence of crop phenology on the behaviour of European roe deer (Capreolus capreolus) to infer the functional roles of crop types in the food‐cover landscape. We analysed the habitat selection and activity patterns of 105 GPS‐collared adult female roe deer using a unique data set combining field‐specific land cover data, region‐specific estimates of crop phenology and weekly harvesting data for three common crops in a French agroecosystem. We found very distinct habitat selection and activity patterns according to crop type, phenological stage and time of day. Wheat and artificial meadows were strongly selected at night‐time during the early and post‐harvest stages only, when roe deer were highly active, suggestive of feeding activity. On the contrary, roe deer strongly selected maize during the day when it was high enough to provide cover, when they were less active, indicating that it was primarily used for refuge. These patterns depended on the availability of more ‘natural’ cover, suggesting that mature maize may substitute for ‘natural’ cover when the latter is scarce. Synthesis and application: Our work highlights the importance of behavioural plasticity and habitat complementation in the persistence of this synanthropic species in agroecosystems. This behavioural adjustment may buffer the consequences of the reduction in natural habitats that accompanies intensification of agricultural production and has implications for understanding how agricultural practices shape the food‐safety trade‐off of wildlife living in these highly modified landscapes.

First evidence of widespread positivity to anticoagulant rodenticides in grey wolves (Canis lupus)

Second-generation Anticoagulant Rodenticides (ARs) can be critical for carnivores, due to their widespread use and impacts. However, although many studies explored the impacts of ARs on small and mesocarnivores, none assessed the extent to which they could contaminate large carnivores in anthropized landscapes.We filled this gap by exploring spatiotemporal trends in grey wolf (Canis lupus) exposure to ARs in central and northern Italy, by subjecting a large sample of dead wolves (n = 186) to the LC-MS/MS method.Most wolves (n = 115/186, 61.8 %) tested positive for ARs (1 compound, n = 36; 2 compounds, n = 47; 3 compounds, n = 16; 4 or more compounds, n = 16). Bromadiolone, brodifacoum and difenacoum, were the most common compounds, with brodifacoum and bromadiolone being the ARs that co-occurred the most (n = 61).Both the probability of testing positive for multiple ARs and the concentration of brodifacoum, and bromadiolone in the liver, systematically increased in wolves that were found at more anthropized sites. Moreover, wolves became more likely to test positive for ARs through time, particularly after 2020.Our results underline that rodent control, based on ARs, increases the risks of unintentional poisoning of non-target wildlife. However, this risk does not only involve small and mesocarnivores, but also large carnivores at the top of the food chain, such as wolves. Therefore, rodent control is adding one further conservation threat to endangered large carnivores in anthropized landscapes of Europe, whose severity could increase over time and be far higher than previously thought. Large-scale monitoring schemes for ARs in European large carnivores should be devised as soon as possible.

Two thousand years of garden urbanism in the Upper Amazon.

A dense system of pre-Hispanic urban centers has been found in the Upano Valley of Amazonian Ecuador, in the eastern foothills of the Andes. Fieldwork and light detection and ranging (LIDAR) analysis have revealed an anthropized landscape with clusters of monumental platforms, plazas, and streets following a specific pattern intertwined with extensive agricultural drainages and terraces as well as wide straight roads running over great distances. Archaeological excavations date the occupation from around 500 BCE to between 300 and 600 CE. The most notable landscape feature is the complex road system extending over tens of kilometers, connecting the different urban centers, thus creating a regional-scale network. Such extensive early development in the Upper Amazon is comparable to similar Maya urban systems recently highlighted in Mexico and Guatemala.

Design of an interpretive trail and conservation of native orchids (Orchidaceae) in an anthropized landscape

Objective: to design an interpretive trail of native orchids in the gardens of Campus Cordoba, Colegio de Postgraduados.Design/Methodology/Approach: this study is descriptive and field based. First, the feasibility of the trail wasvalidated through an online survey. Afterwards, several field trips were conducted; the script was created, andfinally the interpretive script of the trail was validated.Results: of the respondents, 95% considered the orchid interpretive trail as feasible. The inventory of thetrail area allowed to verify that the orchids are accessible at all stations along the route. The design of theinterpretive trail has nine thematic stations: 0. Introduction, 1. The Catasetum trail, 2. In vitro germination, 3.Acclimatization of orchids, 4. Miniature orchids, 5. Establishing orchids in phorophytes, 6. The Laelias trail,7. The “May Flowers” trail, and 8. The “Donkey ears” (Thricocentrum luridum). The interpretive trail allowsanyone to know and appreciate the diversity of wild orchids, 28 species and their phorophytes, along 700 m ofwalking trails for a 2.5-hours route.Limitations of the study/Implications: it is a guided interpretive trail.Findings/Conclusions: The interpretive trail allows us to appreciate the importance of the Orchidaceaefamily; which is one of the largest families in Mexico and the world through environmental and ornamentalimportance.

Negative effects of agricultural open-channel irrigation system on vertebrate populations in central Mexico.

Linear infrastructures such as agricultural irrigation channels produce physical changes and negative impacts to habitats, wildlife populations, communities, and ecosystems. Open irrigation channels act as a pitfall for wildlife and can affect vertebrates of all sizes. Nonetheless, small channels have received relatively little attention by conservation biologists. The objective of this study was to analyze vertebrate species richness and mortality in relation to different sections of an irrigation channel system and the surrounding landscape characteristics. For two years, we conducted monthly surveys along an open-channel irrigation system to estimate its effect on vertebrates through records of dead and alive individuals. We examined the spatial relation of species richness and mortality with transects using a canonical correspondence analysis and chi-squared tests to determine possible variations in the different structures of the channel and seasonality. Further, a landscape diversity index was used to analyze the importance of surrounding habitat structure and composition on these parameters. Most vertebrates (61%) were found dead, small mammals and reptiles were the most affected. Our results indicate that mortality of small vertebrates varies depending on species, structures of the open-channel agricultural irrigation system (i.e., concrete channel and floodgates), seasonality (i.e., wet, and dry), and landscape heterogeneity (i.e., high, medium, and low landscape diversity). The open-channel irrigation system is a threat to populations of small vertebrates in anthropized landscapes, conservation efforts should be directed at protecting water bodies and restructuring the open-channel agricultural irrigation system to avoid mortality of species such as small rodents (M. mexicanus) and reptiles (C. triseriatus, B. imbricata, and Thamnophis spp.).

Pollen movement of the endemic Agave cupreata by bats and birds in western Mexico

Abstract We quantified the amount of pollen carried by bats and birds visiting the flowers of cultivated and wild individuals of the endemic Agave cupreata in western Mexico and estimated the distance to which pollen was moved using diurnal/nocturnal inflorescence exclusions and fluorescent powders. There were no differences in the amount of pollen transported by bats and birds near cultivated and wild agaves, but overall, bats transported greater loads than birds. Nocturnal pollen movement was more frequent, and the maximum distance recorded was 630 m (diurnal and nocturnal), with no transfer between cultivated and wild plants. Bats seem to provide a greater pollination service than birds in our focal anthropized landscape. It is necessary to incorporate management practices into mezcal production that ensure enough food for the wide array of animal species using this resource, which in turn will help to maintain the pollination service.

Plastic ingestion in giant tortoises: An example of a novel anthropogenic impact for Galapagos wildlife

The human population of Galapagos has rapidly increased in the last decades accelerating the anthropogenic pressures on the archipelago's natural resources. The growing human footprint, including inadequate management of garbage, may lead to conservation conflicts. Here, we assessed the ingestion of debris by Western Santa Cruz giant tortoises (Chelonoidis porteri) within human-modified and protected areas. Additionally, we characterized environmental debris and quantified tortoise abundance together with tortoise fecal samples. We processed a total of 6629 fecal samples along a gradient of anthropogenic disturbance based on human debris presence. We found 590 pieces of debris in samples within human-modified areas (mean of 3.97 items/kg of feces) and only two pieces in the protected area (mean of 0.08 items/kg of feces). Plastic waste was the predominant category in feces within the anthropic area (86.3%; n = 511), followed by cloth, metal, paper, synthetic rubber, construction materials, and glass. On average, the proportion of plastic was higher in feces (84%) than it was in environmental debris (67%), denoting that plastics are more readily ingested than other types of debris. We also found that green, white, and light blue plastics were consumed more often than their prevalence in the environment, suggesting color discrimination. Tortoise abundance was higher in the protected area when compared to the human-modified area; however, recapture rates were higher in anthropized landscapes which increases tortoise exposure to plastics and other human associated threats. Our results indicate that plastics are frequently consumed by tortoises in the polluted anthropic areas of western Santa Cruz, but scarce in protected areas. More research is needed to understand the negative impacts associated with plastics for Galapagos terrestrial species. We encourage local stakeholders to implement current policies limiting expansion of urban areas, plastic use, and improving waste management systems to minimize threats to human and animal health.

Trophic interactions between two sympatric mesocarnivores in an anthropized landscape from the Mexican highlands

The study of diets in North American carnivores has been assessed from different methods, essentially analyzing the composition of their diet, and classifying the species based on the breadth of their trophic niche. Still, studies that explore aspects of their interactions are limited. This work studies the predator-prey relationship through an interaction network analysis approach, nesting, and the analysis of core vs peripheral individuals, for two sympatric species of the Mexican highlands, the bobcat (Lynx rufus) and the coyote (Canis latrans). In addition, the effect on the structure of the interaction networks under two conditions of environmental disturbance was evaluated. In environments with high disturbance: A network was obtained for 46 bobcats and 18 coyotes, identifying six bobcats and five core coyotes; and in environments with low disturbance, the network was obtained for 134 bobcats and 38 coyotes, identifying 30 bobcats and eight core coyotes. Three of the analyzed networks presented a nested pattern with the WNOFD metric (High disturbance: L. rufus: Nesting = 0.51, p < 0.05, C. latrans: 4.13, p < 0.05; Low disturbance: L. rufus, 0.91, p < 0.05) and only one network with the NOFD metric was nested (Low disturbance = C. latrans, 19.51, p < 0.05). There was an effect of environmental disturbance on the evaluated networks; in highly disturbed environments, the structure and composition of the interactions are different for both species. Unlike conventional methods for studying the diet of carnivores, our results provide a different methodology that allows characterizing the network of trophic relationships between predators and their prey, evaluating whether their relationships are nested, and analyzing information at the level of individuals and sexes. In subsequent studies, it is relevant to investigate the fragility of the network due to the loss of essential components of its structure, which will allow establishing measures for its conservation. Also, presents for the first time the structure of the trophic interaction network for two sympatric mesocarnivores from the Mexican highlands, as a tool to study their relationships and show mechanisms of their coexistence.

No country for small birds: Potential positive association among medium‐sized, aggressive species in Australian bird communities

AbstractAimAustralian woodlands have been intensively cleared since European settlement and, in parallel, many species of birds inhabiting this habitat type have experienced a marked decline. Conversely, some species such as noisy miner Manorina melanocephala respond positively to habitat disturbance and due to their hyper‐aggressiveness can end up driving away specialized and fragmentation‐sensitive species. Recent studies have suggested that the negative impact of miners is exacerbated by means of synergistic interactions between these and other aggressive species, including nest predators. However, it is not clear if these positive associations arise through similar habitat requirements or due to potential mutual benefits (‘facilitation effects’), which should predominate in harsh environments as the stress‐gradient hypothesis (SGH) predicts.LocationEastern Australia.MethodsWe combined a multi‐season community N‐mixture model and joint species distribution models within the Hierarchical Modelling of Species Communities framework to examine species co‐occurrence patterns after accounting for imperfect detection and the influence of environmental variables. We then explored how the balance between positive and negative associations varied along an abiotic stress gradient and whether species‐to‐species associations were non‐randomly distributed with respect to species traits.ResultsNo significant associations were detected; we only found tentative associations (posterior probability 85%) in a low proportion of species pairs (~4%). Although most non‐random (tentative) associations were negative, these were weaker and less consistent across models than the positive ones. Five medium‐sized species of swooping birds including the noisy miner monopolized virtually all positive associations. Communities from low‐productivity environments tended to show a lower degree of overall (community‐level) competitiveness than those located in less stressful (more productive) environments, which supports the SGH. There was no significant relationship between species trait dissimilarity and species‐to‐species association's strength.Main ConclusionsOur results suggest that aggressive species like miners, kookaburras, lorikeets, magpies and butcherbirds can form potential synergies with each other that may intensify the direct negative influence of each species on small‐sized songbirds. Since these species thrive in anthropized landscapes and have drastically increased their numbers in some regions, their associative potential should be considered in conservation actions.

Landscape anthropization explains the genetic structure of an endemic Mexican bird (Thryophilus sinaloa: Troglodytidae) across the tropical dry forest biodiversity hotspot

Landscape anthropization explains the genetic structure of an endemic Mexican bird (Thryophilus sinaloa: Troglodytidae) across the tropical dry forest biodiversity hotspot

Mapping Cerrado remnants in an anthropized landscape in southeast Brazil

In the eastern São Paulo state, Brazil, a disjoint tropical savanna (Cerrado) site occurs in Vale do Paraíba Paulista. Considering the degradation of Cerrado in the region and that currently LULC mapping is not accurate enough to properly map Cerrado vegetation in an anthropized landscape, we aimed to locate Cerrado remnants in the region and to evaluate the conservation status of these remnants and its main anthropic pressures. We hypothesized that Cerrado pacthes in Vale do Paraíba Paulista were small, irregular in shape, disconnected from each other, and threatened by agriculture and urban expansion, which we found. We also expected that woody formations of Cerrado would predominate in the region, what we observed. Different Cerrado formations covered an area of 3153.35 ha in Vale do Paraíba Paulista, only about 1.5% of original extension, and remnants located within private properties. This study highlighted Cerrado occurrence in Vale do Paraíba Paulista and the need for conservation public policies for this biome in the region.