Volume 89, Issue 2

The Virginia opossum is an animal that plays important roles in ecosystems and is a popular model for ecological studies. However, they are short-lived (average lifespan of 1.1 years), and a question arises: can the data taken from those animals be extrapolated to other years or do their characteristics change as quickly as the members of a population? Therefore, the aim of this article is to compare several characteristics (age, weight, body condition, infestation by fleas, severity of injuries, leucocyte and erythrocyte counts, and isotopic niche) of an opossum population over four years. For this, we trapped opossums in the same location at the same time of year for four years. We found that most characteristics remained similar over the study period; however, there was a change in erythrocyte counts, and the isotopic niche changed every year. A positive correlation was found between the δ 15 N and body condition. This suggests that if left undisturbed, opossum populations maintain their characteristics; however, their diet changes according to food availability. Opossums that are higher in the trophic net (most likely because they consume more carrion) tend to have a higher body condition.

Desert bighorn sheep ( Ovis canadensis ) populations often occur in remote areas at low densities, leading to gaps in knowledge of life history. In November 2011, we translocated 11 female desert bighorn sheep from the Fra Cristobal Mountains and 9 from Red Rock Wildlife Management Area (RRWMA) to the Peloncillo Mountains in southwestern New Mexico. In December 2012, we captured 21 adult females in the Peloncillo Mountains, 14 of which were recaptured from 2011. We fitted each animal with a very high frequency (VHF) collar and vaginal implant transmitter (VIT) to monitor for parturition. We captured 26 lambs (5 females, 7 males in 2012; 7 males, 7 females in 2013), recorded morphometric measurements and fitted lambs with VHF collars to monitor survival. Over the study, 14 lambs died, with 12 mortalities from predation, one from abandonment, and one from unknown causes. Lambing season was protracted over 3–4 months and survival was unrelated to birth timing. Body mass differences between sex varied by year, suggesting a connection to annual climate. Because most studies focus on captive animals with access to supplemental food, captive lambs may not be representative of free-ranging populations. Thus, we investigated morphological trends in a free-ranging population.

Ungulates have undergone major declines in Central and West African forests as a result of bushmeat trade and habitat loss. Monitoring forest ungulate status is a critical conservation need. We undertook a systematic camera-trap survey of the Ngoyla Faunal Reserve within the ∼11,000 km 2 Dja-Ngoyla Complex, part of the critical TRIDOM forest landscape in Central Africa. We deployed cameras at 36 sites over 2,734 camera-trap days. We recorded 3,307 independent detections of 12 species of forest ungulates. The Peters’ duiker and blue duiker were the most abundant, accounting for 71 % of all ungulate detections, both with occupancy >85 %. The black-fronted duiker and white-bellied duiker were relatively widespread but rare. There were very few detections of Bates’ pygmy antelope, sitatunga, forest buffalo, and bongo. These findings are similar to our baseline population estimates of ungulates in the neighbouring Dja World Heritage site. Our study provides further evidence of ecological partitioning among the more abundant duikers based on activity pattern and body size. The Dja-Ngoyla Complex is integral to the 178,000 km 2 TRIDOM conservation landscape. The landscape is a global conservation priority for securing the future of great apes, forest elephant, a community of forest ungulates, and other threatened species in the region.

Limited research appears on the Red Giant Gliding Squirrel ( Petaurista petaurista ) in general and the current study presents the first comprehensive analysis of its activity patterns, feeding behaviour, and food selection of the species in the tropical rainforests of Indian Eastern Himalayas. Surprisingly, the Red Giant Gliding Squirrel exhibited a predominantly frugivorous diet in the current study and deviates from the previously documented florivorous tendencies of Asian gliding squirrels, emphasising the crucial role of the local ecological context in understanding dietary patterns within mammals. When it comes to activity budget, the species spent the majority of the time in feeding followed by resting and travelling. The majority of the activity happened to be in the terminal canopy of the trees.

An overlap of ranges of Nilgiri langurs ( Semnopithecus johnii Fischer, 1829) and tufted gray langurs ( Semnopithecus priam Blyth, 1844) in the Western Ghats resulted in the formation of mixed-species groups (MSGs) with a notable presence of brown morphs and significant changes in group composition and population dynamics. Our study investigated the composition of MSGs and examine the vegetation in their ranges across the Western Ghats. We identified three new locations with MSGs in the Nilgiris and southern Western Ghats predominantly found in deciduous forests (∼50 %), at an average altitude of 621.01 m asl. The mean group size of MSGs was 10.9 ± 4.49 SD The geographic variation in the abundance of Nilgiri and tufted gray langurs, driven by their ecological adaptability and dispersal patterns, provides important insights into their ecological niches in the Western Ghats.

The Mainland leopard cat ( Prionailurus bengalensis bengalensis ) has a wide distribution, but little is known about its ecology in Nepal. We deployed 36 pairs of cameras for three weeks in 2020 in a non-protected area of the Nepalese Himalayan foothills. We obtained 18 leopard cat detections, however simultaneous detections on both flanks never occurred. We used a multi-session spatially-explicit capture-recapture (SECR) model and a Spatial Partial Identity Model (SPIM) to estimate its population density, which was 10.74 (CI = 4.32–26.7) and 12.83 (CCI = 3.09–25.99) individuals per 100 km 2 , suggesting a healthy population for this area.

The distribution of Platyrrhinus guianensis , a species originally considered endemic to the Guiana subregion, has recently been extended to a southernmost Brazilian Amazon point, yet included within the Guiana Shield. Based on comprehensive revisionary work, we extend this species occurrence eastwards and southwards, encompassing 11 localities, including Eastern Amazonia forests. These records correspond to primary and secondary floodplain forest habitats in the Brazilian states of Amapá, Maranhão, Mato Grosso, and Pará.

Swamp rabbits ( Sylvilagus aquaticus ) are a species of conservation concern in several states. We conducted latrine surveys at previously surveyed and new sites from 2021 to 2023 to clarify the species’ current status and distribution at its eastern extent, including the first surveys in South Carolina in > 25 years. We analyzed occupancy to determine what environmental variables affected swamp rabbit occurrence. Detection and occupancy probability from our top model were 0.75 (0.69–0.81 85 % CI ) and 0.32 (0.30–0.35 85 % CI ), respectively. Occupancy decreased with distance to emergent herbaceous or woody wetlands and increased with reduced tree canopy cover. Our results corroborate previous findings that semi-permanent or permanent wetlands are important to swamp rabbits and that they may be more likely to occupy habitats in proximity to open areas with herbaceous vegetation. Our study demonstrated that swamp rabbits persist within northwestern South Carolina, but no detections at 17 % ( n  = 5) of previously known sites, detections at 15 new sites, and observations of the species outside their purported range highlight the opportunity for further studies to assess connectivity of populations in the face of rapid land use change.

The Peruvian coast is considered the southern limit of the distribution area of the pantropical spotted dolphins ( Stenella attenuata) in the Eastern Tropical Pacific. However, sightings of this species were scattered and scarce. This study reports an unexpected increase in sightings of this species in northern Peru from 2021 to 2023. Over this period, a total of 34 groups were recorded, with 85.3 % ( n  = 29) observed just in 2023. This significant rise in sightings suggests shifts in dolphin distribution related to rising sea surface temperatures associated with a strong El Niño event.

The taxonomy, distributional range, and the general biology of the nectar-feeding bat Anoura cadenai are poorly understood, and the species was represented by a few specimens from Colombia deposited in scientific collections. Here, we report the first records of A. cadenai for Venezuela, increasing its range of occurrence and the list of bats known for this country to 174 species. The new records represent the eastmost known localities for A. cadenai and indicate that the species occur over a broader range of habitats than previously reported.

The prairie vole ( Microtus ochrogaster ) has become a model organism for studying monogamy. A precise account of the phylogeography of this species should increase our understanding of the proximate mechanisms and ultimate factors underlying the observed geographic variation in monogamy. The prairie vole is widespread throughout the North American grasslands, and seven subspecies have been identified based on morphological variation, which suggests the development of genetic structure. However, a prior analysis of allelic diversity at nuclear microsatellite loci showed little geographic differentiation throughout the species’ range. To further address this inconsistency, we sequenced a segment of the mitochondrial cytochrome b locus in 34 individuals from separate geographic locations throughout the species’ range. The mitochondrial analysis revealed three widespread genetic clusters without clear geographic patterns. Thus, the results were consistent with the nuclear analysis by demonstrating low geographic differentiation, indicating likely incomplete lineage sorting in the species. Additionally, the observed patterns of mitochondrial and nuclear variation were not consistent with subspecies designations. Based on our analysis and prior genetic and morphological analyses, we suggest that a reevaluation of the subspecies designations in prairie voles is warranted, with the six contiguous subspecies of prairie voles being synonymized.

The family Muridae represents the most diversified clade of rodents. Their remarkable convergent morphology has challenged taxonomists to establish a robust classification. Thanks to molecular phylogenetic analyses, five subfamilies of murid rodents are hereby defined: Lophiomyinae, Deomyinae, Gerbillinae, Leimacomyinae and Murinae. As the single representative of the subfamily Leimacomyinae, Leimacomys buettneri is known only by the first two specimens collected in 1890. It was classified either as belonging to the Dendromurinae (Nesomyidae), or recently placed in its own subfamily Leimacomyinae (Muridae). Here we present the first molecular genetic analysis of the holotype and the paratype of Leimacomys by genomic skimming and assembly of the mitogenomes. It confirms that Leimacomys belongs to the Muridae as a sister to all extant Deomyinae. As a result, we have re-examined the morphology of type specimens and compared them with deomyine taxa as well as Miocene fossil rodents that are considered as murid-like ancestors. This allows us to propose an updated scenario for the origins of the murid lineages. In the light of our novel genetic and morphological data, we propose to keep the subfamily Leimacomyinae, represented by the monotypic Leimacomys , within the family Muridae.

Microtus , the most speciose genus in the tribe Arvicolini, inhabits boreal and temperate regions. Despite recent increase in taxonomic research, the precise species diversity of Microtus voles in Iran is still unclear due to insufficient molecular work. This study aimed to identify Microtus species in West Azerbaijan province, near Turkey and Armenia, by sequencing the mitochondrial cytochrome b (cyt b ) gene from 20 vole specimens. Phylogenetic analyses confirmed the occurrence of Microtus rossiaemeridionalis in Iran for the first time, which has actually been predicted for the western side of Urmia (West Azerbaijan province) on the basis of habitat modelling. This study enhances the understanding of Microtus diversity in Iran, highlighting the need for comprehensive fieldwork and molecular assessments to accurately delineate rodent species composition in the country.