Rita de Cassia Bianchi

The impacts of free-ranging rural dogs on wildlife conservation, including predation and disease transmission, vary by context, highlighting the need to assess their specific effects. This study examines home range size and native habitat use of free-ranging owned rural dogs (FRORD) within protected areas and fragments of the Cerrado biome, Brazil. We monitored each of the 105 FRORDs once over a 2-mo period using GPS collars, between August 2022 and January 2024. Home range sizes were estimated using 95% autocorrelated kernel density estimates, with predictor variables analyzed through generalized linear mixed models. Most FRORD exhibited restricted home ranges (mean = 30.74 ha), with larger home ranges correlated with dogs accompanying owners in daily activities. Native habitat use was also analyzed through generalized linear mixed models, and FRORD primarily occupied farming areas, with only 4% of locations in native habitats. Both home range size and native habitat use were associated with household-level factors, suggesting that local context plays a more important role than individual characteristics. Dog movement patterns are strongly influenced by socio-environmental contexts. These findings facilitate targeted management strategies for specific local contexts, reducing biodiversity impacts and promoting animal welfare.

Biological invasions pose a major threat to biodiversity, yet their nonlethal, behaviorally mediated effects on native wildlife remain poorly understood, particularly in tropical systems. Domestic dogs (Canis familiaris) and wild boars (Sus scrofa) rank among the world’s worst invasive species and are recognized for their significant negative impacts on the ecosystem. Using long-term camera-trap data from two protected areas in Brazilian Cerrado, we investigated how invasive species influence native mammals across temporal and spatial dimensions. The effects of both invasive species were evaluated on seven native mammals with contrasting ecological traits: two canids, an apex predator, and four prey species. We assessed (i) changes in activity patterns through kernel density overlap, (ii) short-term attraction or avoidance using piece-wise exponential additive mixed models, and (iii) spatial responses via abundance-mediated multi-species occupancy models. Our results reveal that native species responded primarily through temporal adjustments rather than spatial exclusion. Xenarthrans were particularly affected, exhibiting activity pattern shifts that could carry energetic costs given their physiological constraints as imperfect homeotherms. Crab-eating foxes and opossums showed flexible, context-dependent responses. We found an exploratory hypothesis based on spatial trends, suggesting that apex predators may create spatial refugia that buffer native species from invasive species pressure. These findings highlight the urgency of domestic dog control, underscore that apex predator conservation could be a critical component of effective invasive species management, and that their management must be context-dependent.

The impacts of free-ranging rural dogs on wildlife conservation, including predation and disease transmission, vary by context, highlighting the need to assess their specific effects. This study examines the home range and native habitat use of dogs within a protected area and fragments of the Cerrado biome. We monitored 105 dogs using GPS collars over two months. Home ranges were estimated using the 95% autocorrelated kernel density estimate (AKDE), with influential variables analysed through general linear models (GLM). We assessed the number of GPS locations within native habitats for each dog and performed multiple ordinal regression to identify associated variables. Most dogs exhibited restricted home ranges (mean = 30.74 ha, range = 0.89–624.75 ha), with larger ranges correlated to dogs accompanying owners in daily activities. Dogs primarily occupied farming areas and human settlements, with only 4% of their locations recorded in native habitats; use of these areas was associated with lower body condition scores. The likely ecological impact of these dogs stems more from their high density in the matrix, which could reduce habitat connectivity. Dog movement patterns are strongly influenced by the socio-environmental contexts in which they live. These findings facilitate the development of targeted management strategies aimed at specific local contexts, reducing impacts on biodiversity and promoting animal welfare.

The domestic dog Canis familiaris is an exotic species known to have impacts on native fauna and it may induce spatial and temporal segregation in other species as a mechanism to reduce agonistic interactions. The tayra Eira barbara , a medium‐sized, widely distributed mustelid, is one of the species that can be affected. To test this hypothesis, between 2020 and 2022, we installed camera traps in an agricultural landscape composed of a protected area, agro‐livestock areas, an urban area, and several rural households. We calculated the activity patterns, their overlapping coefficients and generated models to explain the species's occupancy and verify possible interferences. We obtained 32 records of tayras and 100 of domestic dogs. In only 8 of 73 sampling points, the two species occurred concomitantly. Activity overlap was 68%; however, at the points where both species occurred, the overlap was 43%. Tayra showed to be positively associated with forest areas, and negatively with agricultural exploitation areas. Dogs predominantly occupied agricultural areas and were negatively related to forest areas. In addition to dog interference, which seems to affect tayra's use of the landscape, environmental conditions are also essential in describing the occupancy of the subordinate species. It is possible that their scansorial habit is important to avoid agonistic events.

Context: Human-induced habitat loss and fragmentation facilitate the presence of domestic dogs (Canis l. familiaris) in natural habitats, posing risks to native wildlife through predation and competition. The nine-banded armadillo (Dasypus novemcinctus) faces increased vulnerability to dog attacks due to frequent pursuits. Aims: We evaluate the effect of predator presence (exotic and native) on the activity pattern and temporal avoidance behaviour of nine-banded armadillos in the Northeast region of São Paulo state, Brazil. Methods: We analysed camera trap data (2020–2022) for co-occurrence activity between nine-banded armadillos and domestic dogs, and native predators. We also investigated temporal variations between armadillo detections in response to the presence of predators. Key results: Nine-banded armadillos and ocelots (Leopardus pardalis) exhibited nocturnal activity, whereas domestic dogs and jaguarundis (Herpailurus yagouaroundi) were diurnal. The activity pattern of nine-banded armadillos remained consistent in the presence of domestic dogs and native predators, although the time between detections increased at sites frequented by dogs and ocelots. Conclusions: Our findings suggest that armadillos may avoid areas frequented by domestic dogs and ocelots over time, even without direct interactions. Implications: Our research may assist conservationists and policymakers in developing domestic dog control to mitigate the impact of domestic dogs on nine-banded armadillos. Controlling domestic dog populations and raising awareness among owners to confine their pets are crucial measures.

Habitat loss and fragmentation are pervasive processes driving the disappearance of populations and species in the Neotropical region. Since species loss may translate into functional loss, assessing changes in the composition of assemblages’ functional traits might improve our understanding of the ecological roles played by species and ecosystem functioning. Here, we investigate how landscape structure and composition impact the functional diversity of terrestrial mammals in 18 forest patches composing eight protected areas in Southern Brazil. We used functional diversity (FD) based on dietary, physical, and behavioral traits and species vulnerability to extinction. We determined which landscape variables (patch size, proportions of forest and sugarcane, and patch isolation) most influenced mammal FD values by using a both-direction stepwise model selection from a linear global model. Finally, we evaluated the role of trophic guilds in explaining the variation in the FD values using a Principal Component Analysis. Between 2012 and 2017, using camera traps, we recorded 26 native medium- and large-sized mammals throughout the protected areas, of which 6 are regionally threatened, and 5 domestic/exotic species. Richness among the forest patches varied from 4 to 24 species (9.05 ± 5.83), while the FD values varied from 1.29 to 6.59 (2.62 ± 1.51). FD variation was best explained by patch size, which exhibited a strong positive correlation (adjusted R² = 0.55, slope = 0.67, p < 0.001). Insectivores and frugivores presented the highest correlation with patch size, explaining most of the variation in the FD values. Our findings strengthen the paramount role of large protected areas in maintaining mammal diversity and their ecological functions in human-modified landscapes.

Camera traps became the main observational method of a myriad of species over large areas. Data sets from camera traps can be used to describe the patterns and monitor the occupancy, abundance, and richness of wildlife, essential information for conservation in times of rapid climate and land‐cover changes. Habitat loss and poaching are responsible for historical population losses of mammals in the Atlantic Forest biodiversity hotspot, especially for medium to large‐sized species. Here we present a data set from camera trap surveys of medium to large‐sized native mammals (>1 kg) across the Atlantic Forest. We compiled data from 5380 ground‐level camera trap deployments in 3046 locations, from 2004 to 2020, resulting in 43,068 records of 58 species. These data add to existing data sets of mammals in the Atlantic Forest by including dates of camera operation needed for analyses dealing with imperfect detection. We also included, when available, information on important predictors of detection, namely the camera brand and model, use of bait, and obstruction of camera viewshed that can be measured from example pictures at each camera location. Besides its application in studies on the patterns and mechanisms behind occupancy, relative abundance, richness, and detection, the data set presented here can be used to study species' daily activity patterns, activity levels, and spatiotemporal interactions between species. Moreover, data can be used combined with other data sources in the multiple and expanding uses of integrated population modeling. An R script is available to view summaries of the data set. We expect that this data set will be used to advance the knowledge of mammal assemblages and to inform evidence‐based solutions for the conservation of the Atlantic Forest. The data are not copyright restricted; please cite this paper when using the data.

Microcystic/reticular (MRV) schwannoma has been described since 2008, but remains a rarely encountered entity. MRV has a predilection for visceral locations and has variable histologic appareances. Given its rarity and anatomic variability, this entity could raise differential diagnostic issues with other tumours and malignancies. We describe the case of a 69-year-old male followed at IRCCS Ospedale Policlinico San Martino of Genoa for his previous history of non-Hodgkin lymphoma. A para-aortic mass was discovered during follow-up, which -due to its stability, also after chemotherapy- had been hypothesized to be a non-lymphomatous lesion; given the dimensions and the site, the mass was removed. Histological evaluation showed a nodule limited by a slight fibrous capsule and characterized by a proliferation of medium-sized fusiform cells, with elongated nuclei and scarce eosinophilic cytoplasm. Given the lack of malignant signs and the strong expression of protein S-100, a diagnosis of mesenchymal neoplasia with expression of neural markers compatible with reticular schwannoma was made. The neoplasm has not recurred since its removal. The case we present is, at our best knowledge, the first described in the retroperitoneum, a site where the exclusion of other mesenchymal malignancies is mandatory. The rarity and variability of presentations could create problems of differential diagnosis both with mucinous-producing carcinomas or with other soft tissue tumours, with myxoid or reticular structure. The description of this case could help raise information on this rare neoplasm and help distinguish it from other malignancies, especially in unusual sites.

Giant anteater (Myrmecophaga tridactyla) populations are decreasing throughout their range. We tested a methodology for individual identification using camera records and fur patterns to estimate the giant anteater population in a protected area of the Brazilian Cerrado. We identified 9 adult individuals and successfully modeled population abundance and density. Our models estimated an adult population of 16.8 (range = 15–19) giant anteaters through a mark‐resight approach and 12.5 individuals (range = 9.7–25.5) through a spatially explicit capture‐recapture approach. Density estimates were 0.3–0.4 animals/km². Using these estimates, we performed a population viability analysis to understand and predict this population's future. We modeled scenarios without direct effects and models simulating a double carrying capacity and the supplementation and removal of individuals. Even in the more optimistic scenarios, the population is predicted to decreases over time, with ≤8 individuals remaining in 100 years. Given the study area surroundings, realistic models include removals of giant anteaters in the population. Identification of giant anteaters using cameras can inspire conservationists to acquire population data throughout its distribution and obtain population trends to evaluate the species' conservation status. Individual identification of giant anteaters using a motion‐sensitive camera design is feasible, opens new avenues for population analyses, and allows the study of population trends in difficult regions. © 2021 The Wildlife Society.

The tayra (Eira barbara) is a common and broadly distributed Neotropical carnivore, yet is not well‐studied. While this species is apparently associated with forested habitats, it also appears tolerant of some anthropogenic disturbance. We deployed 57 unbaited camera traps (n = 4923 trap‐days) in and around a protected area (Furnas do Bom Jesus State Park, São Paulo, Brazil) to survey for tayra and two potentially interactive species: puma (Puma concolor) and free‐ranging dogs (Canis familiaris). We used encounter histories generated from photographs and occupancy models to quantify tayra landscape use in the human‐dominated landscape composed of the protected area that was near a city and surrounded by agricultural lands dominated by small farms. We fit co‐occurrence models to understand whether puma and free‐ranging dogs affected landscape use by tayra. We detected tayra at 44% of sites and found that tayra landscape use increased with the proportion of forest cover within 500 m of the sampling site. Other factors predicting tayra landscape use included whether the sampling site was within the protected area, its distance to water, and slope. Dogs, which are common on the periphery of the protected area, seem to have a weak negative effect on tayra landscape use. Because of the concentration of forest within the park, this is an important protected area for the carnivore population within this human‐modified landscape. Thus, environmental variables, such as forest cover, distance to water, as well as administrative protection status, are important for understanding local‐scale tayra distribution.Abstract in Portuguese is available with online material.