Mammal Research最新文献

Bats are unique among mammals in their capacity for powered flight and present high species diversity and feeding habits in the Neotropical region. Despite the remarkable increase in knowledge on the distribution of neotropical bats in recent decades, information on the species’ occurrence throughout Brazil is still widely heterogeneous, with significant knowledge gaps in many biomes. The Ubajara National Park (PNU), northwestern Ceará, is an area of extreme biodiversity in the Caatinga biome, characterized by several natural caves associated with a noticeable bat community. Herein, we carried out a complementary inventory of bat diversity in the PNU, focusing on six caves and their surrounding foraging sites. Two surveys totaling 36 sampling nights were conducted using complementary methods such as mist nets, harp trap, roosting searches, and acoustic monitoring. Thirty species of bats belonging to eight families were recorded. We found significant complementarity between the sampling methods resulting in the stabilization of the rarefaction curve. Eight species were found in roosting colonies in at least one of the sampled cavities. A total of 965 individuals from 18 species, with the majority belonging to the family Phyllostomidae, were recorded using active sampling techniques. Passive acoustic monitoring yielded 14 different sonotypes of species from the Emballonuridae, Mormoopidae, Molossidae, Vespertilionidae, and Noctilionidae families. The acoustic activity of bats from distinct families was higher in the dry season and varied throughout the night. Two species registered with passive acoustic monitoring were among the captured ones, thus reinforcing the importance of diversifying methodologies to obtain more complete bat inventories.

The Alpine mountain hare (Lepus timidus varronis) and the European hare (Lepus europaeus) live parapatrically along the elevation gradient in the Alps with areas of overlap. Indications suggest competition between the two lagomorph species in overlapping areas. Resource partitioning in form of feeding niche differentiation may reduce competition and enable coexistence. The two hare species hybridise and produce fertile hybrids. To examine foraging behaviour of Alpine mountain hares, European hares and their hybrids in the Alps with particular interest in indications of competition between the two lagomorph species, we performed genetic analysis of hare faecal samples collected on five transects along the altitudinal gradient in the Alps in Grisons (Switzerland) at the middle and the end of the vegetation growth period in the year 2021. We then investigated visually foraging ecology using Fourier-Transform Infrared Spectroscopy (FTIRS). We recorded 32 European hares, 50 Alpine mountain hares, and 18 hybrids. Foraging behaviour of the Alpine mountain hares was different from foraging behaviour of European hares and hybrids. Alpine mountain hares displayed a specialist’s foraging behaviour, whereas European hares and hybrids a generalist’s foraging behaviour. Some Alpine mountain hares inhabiting overlapping elevations with European hares showed feeding niche differentiation, whereas others showed similar feeding behaviour as European hares suggesting competition between the two species about food. Our study underlines that European hares living in the Alps might be a competitor to the Alpine mountain hare. As a specialist, the Alpine mountain hare will be susceptible to future environmental change due to climate change.

The wild boar (Sus scrofa) was introduced to Patagonia in the early 20th century through multiple independent events in Junín de los Andes, the Huemul Peninsula, and Victoria Island (Neuquén Province). Despite uncertainties surrounding their origin, questions persist regarding the extent of hybridization between these populations and domestic or feral pigs. This study presents (i) an analysis of the genetic variability and phylogenetic origin of the sub-Andean population (Neuquén province) of wild pigs from Patagonia using the molecular marker control region and (ii) a population genotyping with the MC1R marker to identify pure wild boar or domestic alleles in the zone. The results confirm the Iberian origin of the Patagonian wild pigs population and suggest potential genetic erosion due to genetic drift, as evidenced by low diversity values (Hd = 0.7950 ± 0.0510 and π = 0.0036 ± 0.0005) compared with previous studies from Argentina and Europe. Moreover, MC1R genotyping reveals the presence of hybrids in the region (allelic frequencies E⁺ = 0.5, E^PD2 = 0.250, E^D1e = 0.250), with a pure core observed on Isla Victoria, Nahuel Huapi National Park (allelic frequency E⁺ = 1). These findings are significant as hybrids contribute to the invasive potential of the species, a concern particularly pertinent in areas with protected habitats. Additionally, the identification of a pure wild boar population on Isla Victoria suggests its potential importance as one of the few remaining pure populations in the country.

Rhagomys is a rare Sigmodontinae rodent from South America that includes three known species: R. rufescens, R. longilingua, and R. septentrionalis. These lineages have an intriguing and disjunct geographic distribution, occurring in forest areas in the Andes and Atlantic Forest. These regions are currently separated by the Cerrado and Chaco, two biomes of open vegetation in South America. Despite recent studies, the reduced number of Rhagomys specimens in zoological collections is the main limiting factor for its better systematic understanding. Here, we compile data from the literature and analyze a comprehensive sampling based on an integrative approach to describe a new Rhagomys species, apparently restricted to the Brazilian Atlantic Forest. This new species is diagnosed by a suite of morphological characters, DNA synapomorphies, and its karyotype. Phylogenetic analyses place the new form as sister of the Rhagomys rufescens, its congeneric species from the Atlantic Forest, and apart from the Andean species, showing a current separation between the Andes and the Atlantic Forest lineages.

The carnassial teeth of Carnivora and Dasyuromorphia are characterized by the enlargement of the carnassial blades and reduction of crushing structures. In some species, the highly carnassialized teeth exhibit a unicuspid talonid with only the hypoconid present (“trenchant heel”). This condition is similar to that seen in the molars of pretribosphenic cladotherians such as Dryolestida, with a single talonid cusp and hypoflexid groove. Tooth wear and reconstruction of the power stroke show that the hypoflexid of the trenchant heel occludes with the paracone of the distal upper antagonist, providing a cutting and guiding function during the power stroke, and maintaining a uniform inclination of the tooth movement up to the point of centric occlusion. In case of the Dasyuromorphia, this occlusal relationship is most pronounced between the distal molars (M4/m4), whereas in the Carnivora it occurs between the upper and lower mesial molars (M1/m1). The occurrence of distal hypoflexid-like grooves is a recurring trend in mammal evolution, before and after the evolution of tribosphenic molars with multicuspid talonid.

After centuries of widespread extinction, the Eurasian beaver Castor fiber has recolonised most of its former extent of occurrence, following international and national protection laws, reintroduction programmes, and unauthorized releases. Beavers provide valuable ecosystem services and multiple benefits to native biodiversity, though their activity may trigger conflicts with humans, especially in highly modified landscapes. Therefore, it is important to monitor their range-expansion, particularly at the early stages of the colonization process. This study quantifies beaver presence in Central and Northern Italy, where reproduction was first detected in recent years after five centuries of absence. A mix of techniques including both direct and indirect signs of presence was adopted to assess the occurrence and status of beavers in the area, retrieving data for the application of density estimators and, thus, population estimates. We document that at least 16 reproductive events occurred between 2021 and early 2023, with at least 55 areas of activity, located across three rivers of Central Italy, corresponding to a minimum of 40 individuals. Seven to ten individuals (in at least 5 areas of activity) were also recorded in Northern regions, in continuity with the populations occurring in neighboring countries beyond the Alps. Given the fast range expansion by the species and the potential for conflict with human activities, alongside the efficiency and applicability of our approach, this type of beaver field survey should be adopted by wildlife managers and policy makers both in areas of established presence but also in potential expansion areas, to develop management plans and to figure out opportunities this returning native species may bring.

The Himalayan brown bear (Ursus arctos isabellinus) has been listed as a critically endangered species in Pakistan due to unfavorable interactions with local populations resulting in agricultural losses and livestock assaults. We investigated the current distribution, activity pattern, and human-bear interaction in Deosai National Park and the surrounding areas in 2021. We used infrared camera traps in 89 locations for 1,272 trap nights to determine the presence and monitor the activity pattern of Himalayan brown bears. We also conducted an in-person survey with 235 respondents living in the study area to understand their perspectives on the human-bear interaction. We placed 89 camera trap stations and collected 103 independent detections, yielding a rate of 8.09 independent detections per 100 trap nights. The bear diel activity showed a bimodal pattern with peaks during mid-day and sunset, and their activity was 11 h during a 24 h. From local communities, we detected that the main concern was livestock depredation and crop loss due to U. arctos isabellinus presence. Our study provides important baseline data for Himalayan brown bears in Deosai National Park, from which we can contribute to the development of conservation plans that resonate with the needs of bears and the people who live with them.

Understanding underlying genetic structure is essential for the conservation and management of rare or uncommon species because it is important to protect their evolutionary potential and adaptability by preserving genetic diversity. Southeastern Myotis (Myotis austroriparius or MYAU) is an uncommon bat species that ranges across much of the southeastern United States. At the state level, MYAU is regarded as endangered or a Species of Greatest Conservation Need across nearly all its distribution. The overall objective of this study was to examine the genetic structure and genetic diversity of MYAU by determining levels of subpopulation connectivity across its range. We collected, sequenced, and analyzed tissue samples from 376 individuals from 38 sites, 11 states, and 8 ecoregions using genotyping-by-sequencing (GBS). We used Sanger sequencing to sequence a portion of the mtDNA control region from 472 tissue samples from 42 sites, 12 states, and 8 ecoregions. GBS results indicated that MYAU has a single, panmictic population with little genetic structure and should be managed as so. Results from mtDNA indicated higher levels of genetic structure, likely due to low effective population size, some level of sex-biased dispersal, and increased mutation rates, but not enough to consider separate management units or clades. Genetic diversity estimates were low to moderate. Results from this study can be used to infer and improve long-term protection and management protocols for MYAU. Researchers and managers should preserve gene flow and ensure subpopulations remain connected by maintaining forest corridors and protecting natural and artificial roosts for MYAU in order to prevent future population segregation.

The lack of knowledge about the distributional patterns of threatened ungulates hinders the implementation of effective strategies for the conservation of their populations in Neotropical savannas. The Orinoquia is one of those ecoregions with limited data, poorly represented in the Colombian National System of Protected Areas. Nevertheless, the savannas of the Orinoquia serve as the habitat for 70% of the ungulate species reported in the country. The objective of our research was to identify the presence of the lowland tapir (Tapirus terrestris) and evaluate its representation in different land cover types and within Protected Areas (PAs) in the department of the Vichada. To accomplish this, we: (i) modeled the ecological niche of the lowland tapir using the MaxEnt algorithm, (ii) classified the potential distribution into three zones of habitat suitability, and (iii) assessed the representativeness of habitat suitability within the land cover of the savanna ecosystem and PAs. The suitable area for the lowland tapir was 134,575 km², with the most representative savanna landscapes being: (i) savannas (118,125 km², 87.8%) and (ii) evergreen broadleaf forests (12,550 km², 9.3%). Furthermore, (2,925 km², 2.2%) of the suitable area was reported within of the Natural Reserves of Civil Society. Our results highlight the ecological importance of private conservation initiatives as a complementary strategy to government PAs as well as contributing to functional connectivity on the regional scale. We provide information on the spatial ecology of the lowland tapir as an input for conservation practitioners and land planning in the savanna of eastern Colombia.

The jaguar (Panthera onca) is endangered throughout its geographical distribution, yet assessments of jaguar population dynamics are scarce. This study uses camera trap data from 4 surveys spanning 8 years to gain knowledge on jaguar population dynamics in Emas National Park (ENP), one of the largest protected areas in the Brazilian Cerrado biome, surrounded by large scale agriculture. We used spatially explicit capture-recapture models (SCR) to estimate jaguar density and population trends, and Cormack-Jolly Seber models (CJS) to estimate apparent survival. We derived estimates of recruitment into the independent population (adult and subadult) from population trends and survival estimates. Baseline detection rates were negatively affected by distance to river, higher for males than females, and on-road than off-road. The movement parameter σ was higher for males than females. Sex-ratio was slightly skewed towards females, and survey specific density estimates ranged from 0.14 (95% CI = 0.07 – 0.30) to 0.25 (95% CI = 0.13 – 0.46) ind./100km², leading to an average annual population growth rate of 0.94 (95% CI = 0.82 – 1.06), i.e., a largely stable population. Survival was high (0.77; 95% CI = 0.57 – 0.89), and some individuals remained in the population for over 10 years, pointing towards a healthy population with low turn-over rates. However, recruitment into the independent population was low (0.19; 95% CI = 0.02 – 0.40), suggesting a somewhat isolated and saturated population. Our results highlight the importance of further conservation strategies to prevent population decline from anthropogenic pressures and stochastic factors.