Showing papers on "Flying squirrel published in 2021"

Stable isotopes reveal unexpected relationships between fire history and the diet of Spotted Owls

Abstract: Although the effects of shifting fire regimes on bird populations have been recognized as important to ecology and conservation, the consequences of fire for trophic interactions of avian species – and raptors in particular – remain relatively unknown. Here, we found that within national parks with long‐standing (40+ years) fire management programmes, California Spotted Owls Strix occidentalis occidentalis consumed predominantly Woodrats Neotoma spp. and Pocket Gophers Thomomys spp.; however, in contrast to our predictions, when their territories experienced more extensive and frequent fire, Spotted Owls consumed proportionally more Flying Squirrels Glaucomys oregonensis. We hypothesize this finding could have been driven by either changes to prey abundance following fires (e.g. increases in flying squirrels) or changes to prey availability (e.g. shifts in forest structure or flying squirrel spatial distribution that increased predation upon them by owls). Our work thus demonstrates that fire may have unexpected consequences for the trophic interactions of raptor species and provides valuable information for the conservation of Spotted Owls in fire‐prone forest landscapes.

Elevational gradients strongly mediate habitat selection patterns in a nocturnal predator

Abstract: Mountain ecosystems contain strong elevational gradients in climate and vegetation that shape species distributions and the structure of animal communities. Nevertheless, studies of habitat selection for individual species rarely account for such gradients that often result in species being managed uniformly across their range, which may not improve conservation as intended. Therefore, we characterized variation in nocturnal habitat selection by 18 GPS‐tagged California spotted owls (Strix occidentalis occidentalis) along a 1400‐m elevational gradient in the Sierra Nevada, California. We characterized three‐dimensional forest structure with light detection and ranging data that we used in mixed‐effects resource‐ and step‐selection analyses of owl habitat selection. At lower elevations, owls selected stands with shorter trees, sites closer to hard edges between tall forests and open areas, sites with less diversity in forest seral types and sites with more ridge and southwest aspects. In contrast, owls at higher elevations selected the opposite. Within public forests that had taller trees and within their home range core (45% kernel density estimate of GPS points) areas, owls selected forests with less and more canopy cover at low and high elevations, respectively. Outside of their core areas, owls selected areas with fewer and more tall trees at low and high elevations, respectively. These findings may be explained by elevational gradients in prey distribution and variation in owl diet because owls consume more woodrats (Neotoma spp; earlier seral species) at lower elevations and more flying squirrels (Glaucomys sabrinus; older forest species) at higher elevations. Thus, at low elevations and in areas unlikely to support nesting, spotted owls could benefit from management that promotes woodrat habitat by encouraging oak regeneration and creating small brushy openings within forests with shorter (younger) trees. Conversely, at higher elevations, (1) enhancing flying squirrel habitat by promoting large trees and denser canopy on mesic sites and (2) managing for greater cover type diversity on southwest‐facing slopes and ridgetops is more likely to improve foraging habitat quality for spotted owls. The patterns of owl selection over elevational gradients has not been explicitly considered in most habitat management plans but clearly would improve management throughout mountain ecosystems.

Distribution and relative abundance of Indian Giant Flying Squirrel (Petaurista philippensis) in Gujarat, India

Abstract: We assessed the distribution pattern and abundance of Petaurista philippensis in the state of Gujarat, India. Itis the only species of flying squirrel found in the western states of India. The species was distributed on a large geographic area with confined populations in the eastern dry and moist deciduous forest stretch with tall trees within the state. During the study period, 33 times flying squirrels were encountered at 14 sites in 7 districts, concentrated mainly in protected areas. The overall encounter rate was 0.50 individuals/km among which, the central districts of Gujarat showed the highest while the north-east districts showed the lowest abundance of P. philippensis. It was found to be a tree-dwelling species, positively associated with old-growth forests with tall trees. The abundance rates were found to be associated with forest degradation and hunting practices. Illegal hunting practices persists in some areas of Gujarat, may affect the population number and trend. Apart from forest degradation and fragmentation, hunting for domestic consumption, ethnomedicinal uses, traditions, and human-made forest fires were the major potent threats of flying squirrels as found during the present study.

A de novo genome assembly and annotation of the southern flying squirrel (Glaucomys volans).

Abstract: Northern (Glaucomys sabrinus) and southern (Glaucomys volans) flying squirrels are widespread species distributed across North America. Northern flying squirrels are common inhabitants of the boreal forest, also occurring in coniferous forest remnants farther south, whereas the southern flying squirrel range is centered in eastern temperate woodlands. These two flying squirrel species exhibit a hybrid zone across a latitudinal gradient in an area of recent secondary contact. Glaucomys hybrid offspring are viable and can successfully backcross with either parental species, however, the fitness implications of such events are currently unknown. Some populations of G. sabrinus are endangered, and thus, interspecific hybridization is a key conservation concern in flying squirrels. To provide a resource for future studies to evaluate hybridization and possible introgression, we sequenced and assembled a de novo long-read genome from a G. volans individual sampled in southern Ontario, Canada, while four short-read genomes (two G. sabrinus and two G. volans, all from Ontario) were resequenced on Illumina platforms. The final genome assembly consisted of approximately 2.40 Gb with a scaffold N50 of 455.26 Kb. benchmarking universal single-copy orthologs reconstructed 3742 (91.2%) complete mammalian genes and genome annotation using RNA-Seq identified the locations of 19,124 protein-coding genes. The four short-read individuals were aligned to our reference genome to investigate the demographic history of the two species. A principal component analysis clearly separated resequenced individuals, while inferring population size history using the pairwise sequentially Markovian coalescent model noted an approximate species split 1 million years ago, and a single, possibly recently introgressed individual.

Phylogenetic and morphological significance of an overlooked flying squirrel (Pteromyini, Rodentia) from the eastern Himalayas with the description of a new genus.

Abstract: The flying squirrels (Pteromyini, Rodentia) are the most diverse and widely distributed group of gliding mammals. Taxonomic boundaries and relationships within flying squirrels remain an area of active research in mammalogy. The discovery of new specimens of Pteromys ( Hylopetes) leonardi Thomas, 1921 previously considered a synonym of Hylopetes alboniger, in Yunnan Province, China allowed a morphological and genetic reassessment of the status of this taxon. Phylogenetic reconstruction was implemented using sequences of two mitochondrial (12S ribosomal DNA and 16S ribosomal DNA) and one nuclear (interphotoreceptor retinoid-binding protein) gene fragments. Morphological assessments involved examinations of features preserved on skins, skulls, and penises of museum specimens, supplemented with principal component analysis of craniometric data. Together these assessments revealed that this taxon should be recognized not only as a distinct species, and should also be placed within a new genus, described here as Priapomys.

Aliveria mojmiri sp. nov. among other flying and ground squirrels (Rodentia, Mammalia) from the early Miocene of Mokrá-Quarry sites (Moravia, Czech Republic)

Abstract: This article focuses on the sciurid (Rodentia, Sciuridae) remains from the early Miocene (MN4) Mokra-Quarry sites, Moravia, Czech Republic. The sciurid assemblage in the different fissures ranges from one genus in MWQ4/2018 to three different genera in MCQ3/2005. Regarding subfamily Sciurinae, the dentognathic remains are referred to Palaeosciurus aff. fissurae, which shows an intermediate stage of evolution between Palaeosciurus fissurae and Palaeosciurus sutteri according to the development of conules in both upper and lower molars. Although the sciurid postcranial remains are left unassigned, several calcanei show strong morphological features belonging to ground squirrels, and, are therefore attributed to cf. Palaeosciurus. As for Pteromyinae subfamily, three genera were recovered (Miopetaurista, Blackia and Aliveria), including a new species: Aliveria mojmiri sp. nov. The new species shows a more specialised dental pattern and could further represent the ancestral species from which several middle Miocene genera evolved. Furthermore, some of the recovered calcanei have been here identified as cf. Aliveria, representing the first postcranial remains ever belonging to the genus, and confirm its attribution as a flying squirrel. The presence of both ground and flying squirrels is in concordance with an open landscape with patches of woodland proposed for Mokra-Quarry sites.

San Bernardino Flying Squirrel Use of Residential Areas: A Citizen Science Approach

Abstract: The San Bernardino flying squirrel (Glaucomys oregonensis californicus) is a California Species of Special Concern restricted to montane forests of southern California. We confirmed the distribution of this species in residential areas of the San Bernardino and San Jacinto Mountains with the assistance of citizen scientist volunteers. Project participants placed motion sensor camera traps near bird feeders on their property and uploaded their results to a project webpage and associated iNaturalist project. Flying squirrels were documented at all sites monitored in the San Bernardino Mountains but were not detected in the San Jacinto Mountains, consistent with survey results in recent decades. Forest structure plots between the 2 ranges differed in tree density, tree height, litter depth, and canopy closure, but it is unclear whether these differences alone can explain the lack of detections in the San Jacinto Mountains. Habitat in residential areas may provide subsidized food and water resources that are attractive to flying squirrels and important to their persistence, especially in seasonally dry forests and areas subject to prolonged drought, such as those in the study area.

A de novo genome assembly and annotation of the southern flying squirrel (Glaucomys volans)

Abstract: Northern (Glaucomys sabrinus) and southern (Glaucomys volans) flying squirrels are widespread species distributed across much of North America. Northern flying squirrels are common inhabitants of the boreal forest, also occurring in coniferous forest remnants farther south, whereas the southern flying squirrel range is centered in eastern temperate woodlands. These two flying squirrel species exhibit a hybrid zone across a latitudinal gradient in an area of recent secondary contact. Glaucomys hybrid offspring are viable and can successfully backcross with either parental species, however, the fitness implications of such events are currently unknown. Some populations of G. sabrinus are endangered, and thus, interspecific hybridization is a key conservation concern in flying squirrels. We sequenced and assembled a de novo long-read genome from a G. volans individual sampled in southern Ontario, Canada, while four short-read genomes (2 G. sabrinus and 2 G. volans, all from Ontario) were re-sequenced on Illumina platforms. The final genome assembly consisted of approximately 2.40Gb with a scaffold N50 of 455.26Kb. Benchmarking Universal Single-Copy Orthologs reconstructed 3,742 (91.2%) complete mammalian genes, and genome annotation using RNA-seq identified the locations of 19,124 protein-coding genes. The four short-read individuals were aligned to our reference genome to investigate the demographic history of the two species. A Principal Component Analysis clearly separated re-sequenced individuals, while inferring population size history using the Pairwise Sequentially Markovian Coalescent model noted an approximate species split one million years ago, and a single, possibly recently introgressed individual.

Observation of Infanticide in the Particolored Flying Squirrel (Hylopetes alboniger) from a Forest in Northeastern Bangladesh

Abstract: . Infanticide, the intentional killing of conspecific infants, has been observed widely in mammals, including squirrels. Several ground squirrels revealed this behavioral anomaly, yet no report has been published on the flying squirrels. We report an observation of killing an infant of the particolored flying squirrel (Hylopetes alboniger) by a conspecific adult intruder in Satchari National Park of northeast Bangladesh. Among the several adaptive explanations for infanticide, our observations point to sexual selection in males that confers a competitive advantage by making females receptive. However, the resource competition hypothesis, where the intruder's offsprings gain access to resources as a result of the infanticide cannot be ruled out. Extensive studies are needed to document the extent of infanticide in flying squirrels and their adaptive significance.