Elucidating the sustainability of 700 y of Inuvialuit beluga whale hunting in the Mackenzie River Delta, Northwest Territories, Canada.

Beluga whales play a critical role in the subsistence economies and cultural heritage of Indigenous communities across the Arctic, yet the effects of Indigenous hunting on beluga whales remain unknown. Here, we integrate paleogenomics, genetic simulations, and stable δ13C and δ15N isotope analysis to investigate 700 y of beluga subsistence hunting in the Mackenzie Delta area of northwestern Canada. Genetic identification of the zooarchaeological remains, which is based on radiocarbon dating, span three time periods (1290 to 1440 CE; 1450 to 1650 CE; 1800 to 1870 CE), indicates shifts across time in the sex ratio of the harvested belugas. The equal number of females and males harvested in 1450 to 1650 CE versus more males harvested in the two other time periods may reflect changes in hunting practices or temporal shifts in beluga availability. We find temporal shifts and sex-based differences in δ13C of the harvested belugas across time, suggesting historical adaptability in the foraging ecology of the whales. We uncovered distinct mitochondrial diversity unique to the Mackenzie Delta belugas, but found no changes in nuclear genomic diversity nor any substructuring across time. Our findings indicate the genomic stability and continuity of the Mackenzie Delta beluga population across the 700 y surveyed, indicating the impact of Inuvialuit subsistence harvests on the genetic diversity of contemporary beluga individuals has been negligible.

Circumpolar phylogeography and demographic history of beluga whales reflect past climatic fluctuations.

Several Arctic marine mammal species are predicted to be negatively impacted by rapid sea ice loss associated with ongoing ocean warming. However, consequences for Arctic whales remain uncertain. To investigate how Arctic whales responded to past climatic fluctuations, we analysed 206 mitochondrial genomes from beluga whales (Delphinapterus leucas) sampled across their circumpolar range, and four nuclear genomes, covering both the Atlantic and the Pacific Arctic region. We found four well-differentiated mitochondrial lineages, which were established before the onset of the last glacial expansion ~110 thousand years ago. Our findings suggested these lineages diverged in allopatry, reflecting isolation of populations during glacial periods when the Arctic sea-shelf was covered by multiyear sea ice. Subsequent population expansion and secondary contact between the Atlantic and Pacific Oceans shaped the current geographic distribution of lineages, and may have facilitated mitochondrial introgression. Our demographic reconstructions based on both mitochondrial and nuclear genomes showed markedly lower population sizes during the Last Glacial Maximum (LGM) compared to the preceding Eemian and current Holocene interglacial periods. Habitat modelling similarly revealed less suitable habitat during the LGM (glacial) than at present (interglacial). Together, our findings suggested the association between climate, population size, and available habitat in belugas. Forecasts for year 2100 showed that beluga habitat will decrease and shift northwards as oceans continue to warm, putatively leading to population declines in some beluga populations. Finally, we identified vulnerable populations which, if extirpated as a consequence of ocean warming, will lead to a substantial decline of species-wide haplotype diversity.

Influence of fatiguing noise on auditory evoked responses to stimuli of various levels in a beluga whale, Delphinapterus leucas.

The negative impact of man-made noise on the hearing of odontocetes has attracted considerable recent attention. In the majority of studies, permanent or temporary reductions in sensitivity, known as permanent or temporary threshold shift (PTS or TTS, respectively), have been investigated. In the present study, the effects of a fatiguing sound on the hearing of a beluga whale, Delphinapterus leucas, within a wide range of levels of test signals was investigated. The fatiguing noise was half-octave band-limited noise centered at 32 kHz. Post-exposure effects of this noise on the evoked responses to test stimuli (rhythmic pip trains with a 45-kHz center frequency) at various levels (from threshold to 60 dB above threshold) were measured. For baseline (pre-exposure) responses, the magnitude-versus-level function featured a segment of steep magnitude dependence on level (up to 30 dB above threshold) that was followed by a plateau segment that featured little dependence on level (30 to 55 dB above threshold). Post-exposure, the function shifted upward along the level scale. The shift was 23 dB at the threshold and up to 33 dB at the supra-threshold level. Owing to the plateau in the magnitude-versus-level function, post-exposure suppression of responses depended on the stimulus level such that higher levels corresponded to less suppression. The experimental data may be modeled based on the compressive non-linearity of the cochlea. According to the model, post-exposure responses of the cochlea to high-level stimuli are minimally suppressed compared with the pre-exposure responses, despite a substantially increased threshold.

Cardiorespiratory Responses to Acoustic Noise in Belugas.

To date, most research on the adverse effects of anthropogenic noise on marine mammals has focused on auditory and behavioral responses. Other responses have received little attention and are often ignored. In this study, the effect of acoustic noise on heart rate was examined in captive belugas. The data suggest that (1) heart rate can be used as a measure of physiological response (including stress) to noise in belugas and other cetaceans, (2) cardiac response is influenced by parameters of noise and adaptation to repeated exposure, and (3) cetacean calves are more vulnerable to the adverse effect of noise than adults.

Spectrum pattern resolution after noise exposure in a beluga whale, Delphinapterus leucas: Evoked potential study.

Temporary threshold shift (TTS) and the discrimination of spectrum patterns after fatiguing noise exposure (170 dB re 1 µPa, 10 min duration) was investigated in a beluga whale, Delphinapterus leucas, using the evoked potential technique. Thresholds were measured using rhythmic (1000/s) pip trains of varying levels and recording the rhythmic evoked responses. Discrimination of spectrum patterns was investigated using rippled-spectrum test stimuli of various levels and ripple densities, recording the rhythmic evoked responses to ripple phase reversals. Before noise exposure, the greatest responses to rippled-spectrum probes were evoked by stimuli with a low ripple density with a decrease in the response magnitude occurring with an increasing ripple density. After noise exposure, both a TTS and a reduction of the responses to rippled-spectrum probes appeared and recovered in parallel. The reduction of the responses to rippled-spectrum probes was maximal for high-magnitude responses at low ripple densities and was negligible for low-magnitude responses at high ripple densities. It is hypothesized that the impacts of fatiguing sounds are not limited by increased thresholds and decreased sensitivity results in reduced ability to discriminate fine spectral content with the greatest impact on the discrimination of spectrum content that may carry the most obvious information about stimulus properties.

The limits of applicability of the sound exposure level (SEL) metric to temporal threshold shifts (TTS) in beluga whales, Delphinapterus leucas.

The influence of fatiguing sound level and duration on post-exposure temporary threshold shift (TTS) was investigated in two beluga whales (Delphinapterus leucas). The fatiguing sound was half-octave noise with a center frequency of 22.5 kHz. TTS was measured at a test frequency of 32 kHz. Thresholds were measured by recording rhythmic evoked potentials (the envelope following response) to a test series of short (eight cycles) tone pips with a pip rate of 1000 s(-1). TTS increased approximately proportionally to the dB measure of both sound pressure (sound pressure level, SPL) and duration of the fatiguing noise, as a product of these two variables. In particular, when the noise parameters varied in a manner that maintained the product of squared sound pressure and time (sound exposure level, SEL, which is equivalent to the overall noise energy) at a constant level, TTS was not constant. Keeping SEL constant, the highest TTS appeared at an intermediate ratio of SPL to sound duration and decreased at both higher and lower ratios. Multiplication (SPL multiplied by log duration) better described the experimental data than an equal-energy (equal SEL) model. The use of SEL as a sole universal metric may result in an implausible assessment of the impact of a fatiguing sound on hearing thresholds in odontocetes, including under-evaluation of potential risks.

Hearing threshold shifts and recovery after noise exposure in beluga whales, Delphinapterus leucas.

Temporary threshold shift (TTS) after loud noise exposure was investigated in a male and a female beluga whale (Delphinapterus leucas). The thresholds were evaluated using the evoked-potential technique, which allowed for threshold tracing with a resolution of ~1 min. The fatiguing noise had a 0.5 octave bandwidth, with center frequencies ranging from 11.2 to 90 kHz, a level of 165 dB re. 1 µPa and exposure durations from 1 to 30 min. The effects of the noise were tested at probe frequencies ranging from -0.5 to +1.5 octaves relative to the noise center frequency. The effect was estimated in terms of both immediate (1.5 min) post-exposure TTS and recovery duration. The highest TTS with the longest recovery duration was produced by noises of lower frequencies (11.2 and 22.5 kHz) and appeared at a test frequency of +0.5 octave. At higher noise frequencies (45 and 90 kHz), the TTS decreased. The TTS effect gradually increased with prolonged exposures ranging from 1 to 30 min. There was a considerable TTS difference between the two subjects.

The taxonomic position of Tonkinomys daovantieni (Rodentia: Muridae) based on karyological and molecular data.

Tonkinomys daovantieni was recently described from Northern Vietnam, but very sparse information exists for the taxon. We report for the first time the karyotype of this species and investigate its phylogenetic position in the Dacnomys division using both mitochondrial and nuclear genetic data. The diploid chromosome number of the species is 2n=44. This chromosomal set consists of one submetacentric pair, one metacentric pair, and nineteen pairs of subtelocentric/acrocentric autosomes progressively decreasing in size. The X chromosome is submetacentric and approximately equal in size to the largest subtelocentric autosome. The Y chromosome is metacentric and equal in size to the smallest pair of autosomes. The phylogenetic reconstruction based on the Cyt b COI and GHR genes reveals that Saxotilomys paulinae, a species distributed in the karst formations of the Lao PDR, is the closest relative to T. daovantieni. These two taxa are similar not only in a number of morphological characters, but also in their major ecological preferences (both are petrophylic species associated with limestone karst formations). Based on our data, we can conclude that the similarities among the ecological adaptations, natural conditions and habitat preferences of these species are a reflection of their phylogenetic relationship.

New data on the distribution and diversity of the Tonkin limestone rat (Tonkinomysdaovantieni, Rodentia, Muridae).

The paper presented novel findings of little-known species of rodents the Tonkin limestone rat Tonkinomysdaovantieni in Cao Bang Province, Vietnam with its morphological and genetic characterisation. The study summarises data on the distribution of this data-deficient species, available museum collections, genetic samples, information on its taxonomy and ecology, important to establish the proper conservation status of the species. An exhaustive map of the findings is provided. It is shown that, based on the data currently available, the species does not require taxonomic revision and also, apparently, does not need a special conservation measure; its status may be established to date as Near Threatened B1a+2a and the current population trend - Stable, IUCN.

Seasonal space use and habitat selection of GPS collared snow leopards (Panthera uncia) in the Mongolian Altai range.

Although the home range and habitat selection of animal species is among the fundamental pieces of biological information collected by research projects during recent decades, published information on the snow leopard (Panthera uncia) home range is limited. The Altai Mountains of central Asia contain some of the largest and most important remaining conservation landscapes for snow leopards globally, but there is a limited understanding of the species' ecology in this region. First, we used the data from 5 snow leopards equipped with GPS collars at four study sites in the Altai Mountains of Mongolia to broadly characterize patterns of home range use between 2013 and 2019. The data was used to calculate home range size from a 10 month period using three different estimators: minimum convex polygons (MCP), kernel density distributions (KDE), and local convex hulls (LoCoH). Second, ten data sets from 8 individual snow leopards were combined to cover all 12 months of a year and to generate a general additive mixed model of seasonal home range use and seasonal resource use. We found 1) large variation in home ranges between sites during the monitoring period ranging minimally between 26.1 and 395.3km2 (MCP); 2) Local convex hull home ranges were smaller compared to home ranges based on minimum convex polygons and kernels and yielded more biologically appropriate home range estimates; 3) monthly home ranges of males were larger than females; 4) female monthly home ranges decreased in summer, while male monthly range use remained stable throughout the year; and, 5) while both sexes shared similar habitat preference in winter (steep south-western slopes at high elevation), our data suggest different habitat preferences between sexes in summer. Knowledge of the space use of threatened species is crucial for their conservation, and this is especially true for apex predators who often provide benefits for an entire ecosystem. Our study provides a preliminary understanding of the spatial ecology of this important species in an area of critical conservation concern.

Anthropogenic Neighborhood Impact on Bacterial and Fungal Communities in Polar Bear Feces.

Climate changes cause a dramatical increase in the ice-free season in the Arctic, forcing polar bears ashore, closer to human settlements associated with new and non-natural food objects. Such a diet may crucially transform the intestinal microbiome and metabolism of polar bears. The aim of this study was to characterize changes in the gut bacterial and fungal communities resulting from the transition to anthropogenic food objects by the means of 16S and ITS metabarcoding. Thus, rectal samples from 16 wild polar bears from the Kara-Barents subpopulation were studied. Human waste consuming resulted in a significant increase in the relative abundance of fermentative bacteria (Lactobacillaceae, Leuconostocaceae, and Streptococcaceae) and a decrease in proteolytic Enterobacteriaceae. However, the alpha-diversity parameters remained similar. Also, for the first time, the composition of the fungal community of the polar bear intestine was determined. Diet change is associated with the displacement of eurybiontic fungi (Thelebolus, Dipodascus, Candida (sake), and Geotrichum) by opportunistic Candida (tropicalis), Kazachstania, and Trichosporon. Feeding on human waste does not cause any signs of dysbiosis and probably leads to adaptive changes in the bacterial microbiome. However, the emergence of fungal facultative pathogens increases the risk of infections.

Sleep in the lesser mouse-deer (Tragulus kanchil).

The mouse-deer or chevrotains are the smallest of the ungulates and ruminants. They are characterized by a number of traits which are considered plesiomorphic for the Artiodactyla order. The objective of this study was to examine sleep in the lesser mouse-deer (Tragulus kanchil), which is the smallest in this group (body mass < 2.2 kg). Electroencephalogram, nuchal electromyogram, electrooculogram, and body acceleration were recorded in four adult mouse-deer females using a telemetry system in Bu Gia Map National Park in Vietnam. The mouse-deer spent on average 49.7 ± 3.0% of 24 h in non-rapid eye movement (NREM) sleep. REM sleep occupied 1.7 ± 0.3% of 24 h or 3.2 ± 0.5% of total sleep time. The average duration of REM sleep episodes was 2.0 ± 0.2 min, the average maximum was 5.1 ± 1.1 min, and the longest episodes lasted 8 min. NREM sleep occurred in sternal recumbency with the head held above the ground while 64.7 ± 6.4% of REM sleep occurred with the head resting on the ground. The eyes were open throughout most of the NREM sleep period. The mouse-deer displayed polyphasic sleep and crepuscular peaks in activity (04:00-06:00 and 18:00-19:00). The largest amounts of NREM occurred in the morning (06:00-09:00) and the smallest before dusk (at 04:00-06:00). REM sleep occurred throughout most of the daylight hours (08:00-16:00) and in the first half of the night (19:00-02:00). We suggest that the pattern and timing of sleep in the lesser mouse-deer is adapted to the survival of a small herbivorous animal, subject to predation, living in high environmental temperatures in the tropical forest undergrowth.

Current trends suggest most Asian countries are unlikely to meet future biodiversity targets on protected areas.

Aichi Target 11 committed governments to protect ≥17% of their terrestrial environments by 2020, yet it was rarely achieved, raising questions about the post-2020 Global Biodiversity Framework goal to protect 30% by 2030. Asia is a challenging continent for such targets, combining high biodiversity with dense human populations. Here, we evaluated achievements in Asia against Aichi Target 11. We found that Asia was the most underperforming continent globally, with just 13.2% of terrestrial protected area (PA) coverage, averaging 14.1 ± SE 1.8% per country in 2020. 73.1% of terrestrial ecoregions had <17% representation and only 7% of PAs even had an assessment of management effectiveness. We found that a higher agricultural land in 2015 was associated with lower PA coverage today. Asian countries also showed a remarkably slow average annual pace of 0.4 ± SE 0.1% increase of PA extent. These combined lines of evidence suggest that the ambitious 2030 targets are unlikely to be achieved in Asia unless the PA coverage to increase 2.4-5.9 times faster. We provided three recommendations to support Asian countries to meet their post-2020 biodiversity targets: complete reporting and the wider adoption "other effective area-based conservation measures"; restoring disturbed landscapes; and bolstering transboundary PAs.

Assurance of the existence of a trans-boundary population of the snow leopard (Panthera uncia) at Tsagaanshuvuut - Tsagan-Shibetu SPA at the Mongolia-Russia border.

The existence of a trans-boundary population of the snow leopard (Panthera uncia) that inhabits the massifs of Tsagaanshuvuut (Mongolia) - Tsagan-Shibetu (Russia) was determined through non-invasive genetic analysis of scat samples and by studying the structure of territory use by a collared female individual. The genetic analysis included species identification of samples through sequencing of a fragment of the cytochrome b gene and individual identification using a panel of 8 microsatellites. The home range of a female snow leopard marked with a satellite Global Positioning System (GPS) collar was represented by the minimum convex polygon method (MCP) 100, the MCP 95 method and the fixed kernel 95 method. The results revealed insignificant genetic differentiation between snow leopards that inhabit both massifs (minimal fixation index [FST ]), and the data testify to the unity of the cross-border group. Moreover, 5 common individuals were identified from Mongolian and Russian territories. This finding clearly shows that their home range includes territories of both countries. In addition, regular movement of a collared snow leopard in Mongolia and Russia confirmed the existence of a cross-border snow leopard group. These data support that trans-boundary conservation is important for snow leopards in both countries. We conclude that it is crucial for Russia to study the northern range of snow leopards in Asia.

First cytogenetic analysis of lesser gymnures (Mammalia, Galericidae, Hylomys) from Vietnam.

Gymnures are an ancient group of small insectivorous mammals and are characterized by a controversial taxonomic status and the lack of a description of karyotypes for certain species. In this study, conventional cytogenetic techniques (Giemsa, CBG- and GTG-banding, Ag-NOR), CMA3-DAPI staining, and fluorescent in situ hybridization (FISH) with telomeric DNA probes were used to examine for the first time the karyotypes of lesser gymnures of group Hylomyssuillus Müller, 1840 from northern and southern Vietnam. All studied specimens had karyotypes with 2n=48, NFa=64. C-positive heterochromatic blocks existed in centromeric regions of 7 bi-armed autosomes and the submetacentric X chromosome. The Y chromosome is a C-positive and dot-like. The nucleolus organizer regions resided terminally on the short arms of 2 small bi-armed pairs. Positive signals at the telomeres of all chromosomes were revealed by FISH. CMA3-positive blocks were localized on the telomeric and pericentric regions of most bi-armed and acrocentric chromosomes. Despite the large genetic distances between Hylomys Müller, 1840, lesser gymnures from H.suillus-group from northern and southern Vietnam have similar karyotypic characteristics.

Revision of Chimarrogale (Lipotyphla: Soricidae) from Vietnam with comments on taxonomy and biogeography of Asiatic water shrews.

We analyzed the complete mitochondrial cytochrome b (cytb) gene and fragments of four nuclear loci: ApoB, RAG2, IRBP1 and BRCA1. These data allowed us to provide new insights into the diversity of the Asiatic water shrews of Indochina. A new, highly divergent genetic lineage of Chimarrogale was found in southern Vietnam, and this lineage included specimens from the provinces of Kon Tum, Dak Lak, and Lam Dong. Such finding represents the newest and southernmost records of Chimarrogale in Indochina. Morphological analysis classified the specimens from southern Vietnam as C. varennei proper, which is restricted to that region, whereas the polymorphic C. himalayica, which contained at least four cytochrome b haplogroups, occurred in central and northern Vietnam and southern China. This distinct C. varennei lineage closely related to the C. platycephalus + C. leander clade suggests the existence of an unknown glacial refuge in Tay Nguyen Plateau, southern Vietnam. Because the Bornean C. phaeura (i) was sister-group of the rest of Chimarrogale sensu lato and (ii) had a high genetic divergence (~15% for cytochrome b) and geographical isolation, we suggest that C. phaeura be placed into a separate genus, Crossogale Thomas, 1921. This genus should also include C. sumatrana (Sumatra) and C. hantu (Peninsular Malaysia). On those grounds, we propose a new classification system for Asiatic water shrews.

Social structure and space use of Amur tigers (Panthera tigris altaica) in Southern Russian Far East based on GPS telemetry data.

To better understand the spatial structure of Amur tigers (Panthera tigris altaica) at the southern edge of their range we fitted 14 tigers (6♀♀ and 8♂♂) with 15 GPS-Argos collars between 2008 and 2011 in 2 study sites: the Ussuriskii Reserve of southern Sikhote-Alin and the Land of the Leopard National Park in southwest Primorye, Russian Far East. Fixed kernel estimates of male home ranges were larger than those of female home ranges (P < 0.05 [mean 95% fixed kernel(♀) = 401 ± 205 km(2) ; mean 95% fixed kernel(♂) = 778 ± 267 km(2)]). The home range size of females varied greatly, but on average was similar to estimates derived from earlier work further north. Low overlap of adjacent home ranges suggested that females retained exclusive territories. Real core areas of females overlapped only slightly, and remained stable over multiple years. The home ranges of adult males were smaller than those of males to the north, and in contrast to previous studies, high overlap among males indicated the absence of territoriality. Nonetheless, real core areas of males did not overlap, suggesting some spatial separation. In comparison to other tiger populations and other areas of the Russian Far East, the sex ratio in our 2 study areas was highly skewed towards males. We believe this skewed sex ratio resulted in the dissolution of territoriality of males due to an inability to defend individual females, with males resorting to scramble competition for mates. Continued monitoring of these sites to determine whether shifts in the sex ratio might result in a return to male territoriality would provide confirmation of our tentative hypothesis.

Phylogenetic relationships in the Niviventer-Chiromyscus complex (Rodentia, Muridae) inferred from molecular data, with description of a new species.

Based on molecular data for mitochondrial (Cyt b, COI) and nuclear (IRBP, GHR) genes, and morphological examinations of museum specimens, we examined diversity, species boundaries, and relationships within and between the murine genera Chiromyscus and Niviventer. Phylogenetic patterns recovered demonstrate that Niviventer sensu lato is not monophyletic but instead includes Chiromyscuschiropus, the only previously recognized species of Chiropus. To maintain the genera Niviventer and Chiropus as monophyletic lineages, the scope and definition of the genus Chiromyscus is revised to include at least three distinct species: Chiromyscuschiropus (the type species of Chiromyscus), Chiromyscuslangbianis (previously regarded as a species of Niviventer), and a new species, described in this paper under the name Chiromyscusthomasi sp. n.

Bones and genes: resolution problems in three Vietnamese species of Crocidura (Mammalia, Soricomorpha, Soricidae) and the description of an additional new species.

Recent investigations of Southeast Asian white toothed shrews belonging to the genus Crocidura have revealed discrepancies between the results of morphological and molecular studies. The following study concerns three species of Crocidura occurring in Vietnam, namely Crocidura attenuata, Crocidura tanakae and Crocidura wuchihensis, and an undescribed fourth species revealed by molecular analysis. For many years Crocidura attenuata has been known to occur in Vietnam but, until very recently, the morphologically similar and comparably sized Crocidura tanakae was believed to be restricted to Taiwan. Following several molecular studies over the last few years, this species is now believed to be considerably more widespread and recognised as occuring also in Vietnam. The results of one of these recent molecular studies also revealed the presence of an undescribed species of Crocidura, similar in size and morphology to Crocidura wuchihensis, which is herein described. Data are provided on geographical variation in Vietnam and the problems of defining morphologically similar yet molecularly disparate species are discussed.

Karyotypes of two rare rodents, Hapalomys delacouri and Typhlomys cinereus (Mammalia, Rodentia), from Vietnam.

Karyotypes of Hapalomys delacouri (Rodentia, Muridae) and Typhlomys cinereus (Rodentia, Platacanthomyidae) from Vietnam are described for the first time. The diploid karyotype of Hapalomys delacouri is 38 (NFa=48), consisting of six pairs of bi-armed and 12 pairs of acrocentric autosomes decreasing in size; plus a large metacentric X chromosome and Y chromosome, also metacentric, that is equal in size to the largest pair of acrocentric autosomes. The newly described karyotype differs significantly from that reported for Hapalomys delacouri from northern Thailand. The latter record very likely represents a different species of Hapalomys, possibly the taxon Hapalomys pasquieri described from north-central Laos.The diploid karyotype of Typhlomys cinereus is 38 (NF=48), consisting of five pairs of meta- to submetacentric and 14 pairs of acrocentric chromosomes varying in size from large to small; sex chromosomes were not defined.