Muskoxen Research Articles

Are narwhals critical for the meat supply in East Greenland ?

In East Greenland, the recommendations for the closure of the narwhal (Monodon monoceros) hunt coincide with a pressing demand to continue hunting for meat to supply local communities. By analysing catch statistics and estimating average meat yields, the available meat from marine mammals, polar bears (Ursus maritimus), and muskox (Ovibos moschatus) in East Greenland can be assessed. On average, there was approximately 426 tonnes of meat available per year during this period. However, this quantity declined due to reduced catches of hooded seals (Cystophora cristata) and ringed seals (Phoca hispida) after 2007. This decline was somewhat offset by the inclusion of new species in the hunt, such as dolphins (Delphinidae), killer whales (Orcinus orca), and pilot whales (Globicephala melas). The average annual meat availability per inhabitant decreased from 150 kg before 2008 to 94 kg afterward. Narwhals consistently contributed approximately 5–6% of the total annual meat supply in Greenland over the observed period, which suggests that narwhal meat is not critical for the overall food supply. The inclusion of the need for meat in discussions surrounding sustainable harvest levels has been a point of controversy, particularly in cases where an urgent halt to hunting is needed.

Recent enrichment of megafauna in the north of Eurasia supports the concept of Pleistocene rewilding

‘Pleistocene rewilding' refers to the concept of restoring ecosystems to their state during the Pleistocene epoch, by (re‐)introducing species or their close relatives that were present during that time, in an effort to revive ecological processes that existed before human‐driven extinctions. This concept is highly controversial for both ethical and ecological reasons. Here I review evidence of recent northward range expansions of various large land mammals in boreal Eurasia, and discuss whether this provides evidence that rewilding projects might be justified and feasible. Around 100 years ago, the native boreal fauna of Eurasia included five species of large land mammals: moose Alces alces, brown bear Ursus arctos, wolf Canis lupus, reindeer Rangifer tarandus, and snow sheep Ovis nivicola, but since then the list has expanded. This is due to the introduction of bison Bison bonasus, Bison bison, muskox Ovibos moschatus, non‐native deer, and feral horses, as well as the northward expansion of wild boar Sus scrofa, roe deer Capreolus capreolus, Capreolus pygargus, and red deer Cervus canadensis. In addition, several southern species temporarily occurred in the north, including tiger Panthera tigris, sika deer Cervus nippon, and yak Bos grunniens. This ongoing enrichment of the boreal fauna is reminiscent to Pleistocene rewilding. However, so far, the abundance of expanding large mammals species remains low. Large‐scale projects on Pleistocene rewilding are labor‐intensive, expensive, and not popular enough to receive support, and therefore their realization is problematic

Chromosomal-level reference genome assembly of muskox (Ovibos moschatus) from Banks Island in the Canadian Arctic, a resource for conservation genomics

The muskox (Ovibos moschatus), an integral component and iconic symbol of arctic biocultural diversity, is under threat by rapid environmental disruptions from climate change. We report a chromosomal-level haploid genome assembly of a muskox from Banks Island in the Canadian Arctic Archipelago. The assembly has a contig N50 of 44.7 Mbp, a scaffold N50 of 112.3 Mbp, a complete representation (100%) of the BUSCO v5.2.2 set of 9225 mammalian marker genes and is anchored to the 24 chromosomes of the muskox. Tabulation of heterozygous single nucleotide variants in our specimen revealed a very low level of genetic diversity, which is consistent with recent reports of the muskox having the lowest genome-wide heterozygosity among the ungulates. While muskox populations are currently showing no overt signs of inbreeding depression, environmental disruptions are expected to strain the genomic resilience of the species. One notable impact of rapid climate change in the Arctic is the spread of emerging infectious and parasitic diseases in the muskox, as exemplified by the range expansion of muskox lungworms, and the recent fatal outbreaks of Erysipelothrix rhusiopathiae, a pathogen normally associated with domestic swine and poultry. As a genomics resource for conservation management of the muskox against existing and emerging disease modalities, we annotated the genes of the major histocompatibility complex on chromosome 2 and performed an initial assessment of the genetic diversity of this complex. This resource is further supported by the annotation of the principal genes of the innate immunity system, genes that are rapidly evolving and under positive selection in the muskox, genes associated with environmental adaptations, and the genes associated with socioeconomic benefits for Arctic communities such as wool (qiviut) attributes. These annotations will benefit muskox management and conservation.

Direct and indirect costs of parasitism preceding a population decline of an Arctic ungulate

Parasites negatively affect the fitness of ungulate hosts directly, and in wild ungulates, these effects may be synzootic with other stressors, such as limited nutritional resources. In the Arctic, muskoxen (Ovibos moschatus) occur in a highly seasonal environment and must rely on finite energetic resources for survival and productivity. We investigated the costs of gastrointestinal nematodes on the body condition and reproductive status of 141 muskoxen, on Banks Island, Canada, when the population was at a peak in numbers and density. Using a Partial Least Squares Path Modelling approach, we found that high adult nematode abundance was associated with lower body condition, and high parasite abundance was associated with female reproduction including the indirect effect through on body condition (n = 87). These findings suggest that individuals prioritize energetic reserves for reproduction over parasite defence. In fall 2003, a severe icing event that restricted access to forage was associated with high overwinter mortality of muskoxen and a population crash. Through direct and indirect costs of parasite infection on body condition and reproduction, the high abundance of parasites may have contributed to the effects of this extreme weather event. Understanding the mechanisms in which parasites impact fitness can help explain the ecological drivers of ungulate populations and predict the interactions between the environment and populations.

The first confirmation of North American extinct shrub-ox (Euceratherium, Artiodactyla, Mammalia) in the Early Pleistocene of northern China

Euceratherium is a genus generally considered to represent an Ovibovine member of the Caprini, and up to date considered to occur only in North America. Here, we describe two species of Euceratherium discovered from the Early Pleistocene deposits in northern China, E. collinum and Euceratherium sp., the first confirmed record of Euceratherium in Eurasia and outside North America. The earlier age of Chinese Euceratherium than that of its North American counterpart indicates that Euceratherium might originate from East Asia and spread into North America later. The phylogenetic analysis based on the North American and our Euceratherium collinum materials indicates its closer relationship to Ovibos moschatus than the other bovids. Ecomorphological analysis based on the teeth and metapodials of Euceratherium sp. from Xinyaozi suggests that the Chinese species has the same paleodiet and paleohabitat preferences as those of its North American counterpart. By broadening our study from Euceratherium to its upper taxonomic group, the Quaternary Ovibovine, we found that the latter probably originated from a Kabulicornis-like form and could be divided into two groups in the Late Pliocene, “alticornis” and “depressicornis”. These two groups evolved in Eurasia in the Early Pleistocene. They might disperse from Eurasia to North America twice, in the late Early Pleistocene and the late Middle Pleistocene, respectively.

Detection and Phylogenetic Analysis of Orf Virus and Muskox Rhadinovirus 1 from Muskoxen (Ovibos moschatus) in the Canadian Arctic.

Orf virus (genus Parapoxvirus) has been associated with gross skin lesions on muskoxen (Ovibos moschatus) from Victoria Island, Nunavut, Canada, where muskox populations are experiencing population declines. Orf virus causes painful proliferative and necrotizing dermatitis upon viral replication and shedding, which may lead to animal morbidity or mortality through secondary infections and starvation. Herpesvirus, known to cause gross lesions on skin and mucosa during active viral replication, has also been documented in muskoxen but to date has not been associated with clinical disease. Our objective was to characterize the variation of orf virus and herpesvirus in wild muskoxen of the Canadian Arctic. Tissue samples including gross skin lesions from the nose, lips, and/or legs were opportunistically collected from muskoxen on Victoria Island, Nunavut and Northwest Territories, and mainland Nunavut, Canada, from 2015 to 2017. Sampled muskoxen varied in age, sex, location, hunt type, and body condition. Tissues from 60 muskoxen were tested for genetic evidence of orf virus and herpesvirus infection using PCR targeting key viral genes. Tissues from 38 muskoxen, including 15 with gross lesions, were also examined for histological evidence of orf virus and herpesvirus infection. Eleven muskoxen (10 from Victoria Island and one from mainland Nunavut) with gross lesions had microscopic lesions consistent with orf virus infection. Muskox rhadinovirus 1, a gammaherpesvirus endemic to muskoxen, was detected in 33 (55%) muskoxen including 17 with gross lesions. In all tissues examined, there was no histological evidence of herpesvirus-specific disease. Sequencing and characterization of amplified PCR products using phylogenetic analysis indicated that a strain of orf virus, which appears to be unique, is likely to be endemic in muskoxen from Victoria Island and mainland Nunavut. Many of the muskoxen are also subclinically infected with a known muskox-endemic strain of herpesvirus.

Variation in Muskox (Ovibos moschatus) Guard Hair Growth Rates: Implications for Measuring Chronological Biomarkers.

Segmental analyses of hair may be useful for measuring biomarkers over several seasons to years from a single sample. To attribute hair segments to specific time periods, a known chronological marker, or a hair growth rate, is needed. We examined guard hair growth rates of captive muskoxen (Ovibos moschatus) in Fairbanks, Alaska, USA. We sought to determine if a general growth rate could be applied across muskox populations, thus facilitating the use of segmental analyses for various biomarkers. We used archived samples from 16 muskoxen that had guard hairs sampled at six, 14, and 30 wk after shaving. We measured the lengths of 10 guard hairs per sample, calculated weekly and annual growth rates, and then fitted linear mixed-effects models to assess the effect of different covariates on hair growth rate. The period in which hair had been grown had a significant effect (P<0.05) on growth rate. Extrapolated annual hair growth rates were 277±40 mm/yr (weeks 0-6), 248±47 mm/yr (weeks 7-14), and 165±36 mm/yr (weeks 15-30), with an overall average rate of 210±14 mm/yr. These rates were significantly faster than those of free-ranging Greenland muskoxen-78 mm/yr as measured by stable isotope analyses-and varied intra-annually. This suggests that a universal growth rate cannot be generalized across muskox populations and time.

Brucellosis emergence in the Canadian Arctic

Brucellosis is an important zoonotic disease affecting animals and subsistence harvesters in the circumarctic. We investigated recent trends (2015–2022) of brucellosis seropositivity in caribou (Rangifer tarandus) and muskoxen (Ovibos moschatus) in the Central Canadian Arctic by using data from community-based wildlife health surveillance programs. The overall sample prevalence of Brucella antibodies was 10.0% (n = 271) in muskoxen and 15.5% (n = 277) in caribou. Sample seroprevalence in muskoxen varied geographically with an increasing trend of exposure on NW Victoria Island (from 0% to 36.8% between 2016 and 2022; Kendall tau = 0.283, p = 0.001). The presence of Brucella suis biovar 4 was confirmed by culture from clinical cases in this area. Our results indicate that Brucella suis biovar 4 continues to circulate in the Central Canadian Arctic in caribou and muskoxen and may be now circulating in muskoxen independently from caribou. These findings highlight the need to better understand the ecology and drivers of brucellosis emergence in Arctic multi-host systems.

Species Identification of Inuit Skin and Fur Clothing: Analyses of DNA, Hair Microscopy, and Macroscopical Identification

From approximately 1830 to 1940, through various expeditions to Siberia, Arctic North America, and Greenland, and through donations, the National Museum of Denmark acquired its collection of historical Inuit skin clothing. Unfortunately, original provenance information has been lost for 14% of the garments. In order to document the extensive collection, this study investigates three methods for species identification of animal skin: microscopy of hair, macroscopic identification, and DNA validation. Thus, the present study has two aims: first, to optimise and test hair microscopy for species identification by validating identifications by DNA analyses, and second, to use species identification to estimate the geographic and cultural provenance of Inuit skin clothing. Based on a dataset of well-documented clothing (for positive controls), this study describes an optimised species identification protocol via hair microscopy using transmitted light microscopy (TLM). We demonstrate that the TLM hair protocol is a reliable and inexpensive alternative to molecular approaches when macroscopic identification is doubtful and DNA validation or protein analyses are impossible. In this study we used photomicrographs to document the identifications of caribou (Rangifer tarandus), musk ox (Ovibos moschatus), species of the true seal family (Phocidae), domestic dog (Canis lupus familiaris), wolf (Canis lupus), Arctic fox (Vulpes lagopus), polar bear (Ursus maritimus), wolverine (Gulo gulo), ground squirrel (Urocitellus parryii richardsonii), ermine (Mustela erminea), and cattle (Bos taurus); these identifications can be used for future reference. We conclude that species identification analyses secure the documentation of garments and allow most objects to be contextualized by culture and geography. The studied garments are accessible at the museum website.

The effect of size and density on the mean retention time of particles in reindeer (Rangifer tarandus)

Particle passage from the reticulorumen (RR) depends on particle density and size. A classic way of assessing these effects is the use of plastic markers of varying density and size that are recovered in the faeces. Here, we report results of an experiment where four fistulated reindeer (Rangifer tarandus, 96 ± 12 kg) were fed two different diets (browse, voluntary dry matter intake [DMI] 70 ± 10 g/kg0.75/d; or a pelleted diet, DMI 124 ± 52 g/kg0.75/d) and dosed via fistula with 8 different particle types combining densities of 1.03, 1.22 and 1.44 g/ml and sizes of 1, 10 and 20 mm. Generally, particles that passed the digestive tract intact (not ruminated) did so relatively early after marker dosing, and therefore had shorter mean retention times (MRT) than ruminated particles. On the higher intake, the overall mean retention time (MRT) of particles was shorter, but this was not an effect of shorter MRT for either intact or ruminated particles, but due to a higher proportion of intact particles at the higher intake. This supports the concept that ruminants do not adjust chewing behaviour depending on intake, but that a lower proportion of digesta is submitted to rumination due to pressure-driven escape from the forestomach at higher gut fills. Compared to cattle (Bos primigenius taurus), muskoxen (Ovibos moschatus) and moose (Alces alces) that had received the same markers, reindeer had a lower proportion of 1 mm particles that passed intact. Our results support the concept that the critical size threshold for particles leaving the ruminant forestomach is dependent on body size. While the results likely do not represent findings peculiar for reindeer, they indicate fundamental mechanisms operating in the forestomach of ruminants.

Evaluating the utility of harvester-collected samples for muskox (Ovibos moschatus) pregnancy diagnostics

Monitoring wildlife health in remote and vast regions of the Arctic can be difficult and expensive, but community-based monitoring programs can help alleviate these issues. Reliable bio-monitoring tools, compatible with sample types collected from remote regions, are needed to determine indicators of population health, such as reproductive rates. We sought to establish methods to diagnose pregnancy in muskoxen (Ovibos moschatus) using samples that are commonly collected in harvester-based sampling programs: blood on filter paper and feces. We first evaluated three pregnancy tests, pregnancy-associated glycoproteins (PAG) on filter paper blood samples and fecal progesterone and estrogen metabolites (FPM and FEM), using 12 captive female muskoxen of known pregnancy status. Pregnancy diagnostics using PAG were highly sensitive (100 %) and specific (100 %), with a diagnostic threshold of 19.4 percent positivity (%P) relative to the positive control of the test kit. FPM and FEM diagnostic accuracy differed by hormone and time period. FPM was most accurate in mid-gestation and FEM most accurate in late gestation (sensitivities and specificities of 100 %), but both were overall less accurate than the PAG test during gestation. PAG %P followed a biphasic pattern during gestation, FPM peaked in mid-gestation, and FEM peaked in late-gestation. Following the captive trial, we applied these tests to fecal samples and blood on filter paper samples from 159 adult female muskoxen that were submitted by harvesters through community-based monitoring programs in the Canadian Arctic. The observed patterns of PAG, FPM, and FEM in wild muskoxen throughout gestation were similar to captive muskoxen, though with lower levels of the respective biomarker, requiring different diagnostic thresholds for each test. This work with captive and wild muskoxen provides guidelines for pregnancy diagnostics in muskoxen throughout gestation using samples that can be easily collected by harvesters, allowing for improved monitoring of difficult to access populations through community-based approaches.

Опыт интродукции овцебыков на остров Завьялова в Тауйской губе северной части Охотского моря

The paper describes the process of the beginning of the formation of a population of musk oxen (ovibos moschatus) on Zavyalov Island, peculiarities of adaptation to one of the southernmost habitats with a high density of brown bear population. The purpose of the musk oxen introduction is connected with the implementation of the Arctic Development Strategy and the search for new opportunities of the national economy. Provided that the minimum impact of predators on the population of Zavyalov Island is ensured, it is necessary to prevent a catastrophic increase in the number, which inevitably leads to a shortage of feed. Thus it will be necessary to relocate excess animals. The introduction of musk oxen corresponds to the tourism development plan, and will also serve as an additional, environmentally safe factor in the economy and food independence of remote territories. At the beginning of autumn 2018, 25 musk oxen were brought to Zavyalov Island; all of them were one year old. On the island, musk oxen were initially kept in paddok. On September 10, 2020, another 25 musk oxen were brought. During the first two years, the sex-age structure depended only on their death. Four (4) individuals survived: two (2) males and two (2) females, the strong predation of the brown bear affected. One of them gave offspring in the third year: one calf appeared. In the fourth year, both females from the first delivery gave birth to a calf. Now the island is optimizing the sex-age structure of the musk ox population. But the main patterns of the formation of the population of musk oxen for other islands won’t work on Zavyalov Island due to relatively high number of brown bears, which does not allow the population to develop in the same way as in other habitats, with a much lower density of this predator. The introduction of musk oxen to Zavyalov Island, with good protection from predators, shows a positive result for the settlement of these animals in other similar territories.

Population genomics of the muskox' resilience in the near absence of genetic variation.

Genomic studies of species threatened by extinction are providing crucial information about evolutionary mechanisms and genetic consequences of population declines and bottlenecks. However, to understand how species avoid the extinction vortex, insights can be drawn by studying species that thrive despite past declines. Here, we studied the population genomics of the muskox (Ovibos moschatus), an Ice Age relict that was at the brink of extinction for thousands of years at the end of the Pleistocene yet appears to be thriving today. We analysed 108 whole genomes, including present-day individuals representing the current native range of both muskox subspecies, the white-faced and the barren-ground muskox (O. moschatus wardi and O. moschatus moschatus) and a ~21,000-year-old ancient individual from Siberia. We found that the muskox' demographic history was profoundly shaped by past climate changes and post-glacial re-colonizations. In particular, the white-faced muskox has the lowest genome-wide heterozygosity recorded in an ungulate. Yet, there is no evidence of inbreeding depression in native muskox populations. We hypothesize that this can be explained by the effect of long-term gradual population declines that allowed for purging of strongly deleterious mutations. This study provides insights into how species with a history of population bottlenecks, small population sizes and low genetic diversity survive against all odds.

Geochemical landscapes as drivers of wildlife reproductive success: Insights from a high-Arctic ecosystem

The bioavailability of essential and non-essential elements in vegetation is expected to influence the performance of free-ranging terrestrial herbivores. However, attempts to relate the use of geochemical landscapes by animal populations directly to reproductive output are currently lacking. Here we measured concentrations of 14 essential and non-essential elements in soil and vegetation samples collected in the Zackenberg valley, northeast Greenland, and linked these to environmental conditions to spatially predict and map geochemical landscapes. We then used long-term (1996–2021) survey data of muskoxen (Ovibos moschatus) to quantify annual variation in the relative use of essential and non-essential elements in vegetated sites and their relationship to calf recruitment the following year. Results showed that the relative use of the geochemical landscape by muskoxen varied substantially between years and differed among elements. Selection for vegetated sites with higher levels of the essential elements N, Cu, Se, and Mo was positively linked to annual calf recruitment. In contrast, selection for vegetated sites with higher concentrations of the non-essential elements As and Pb was negatively correlated to annual calf recruitment. Based on the concentrations measured in our study, we found no apparent associations between annual calf recruitment and levels of C, Mn, Co, Zn, Cd, Ba, Hg, and C:N ratio in the vegetation. We conclude that the spatial distribution and access to essential and non-essential elements are important drivers of reproductive output in muskoxen, which may also apply to other wildlife populations. The value of geochemical landscapes to assess habitat-performance relationships is likely to increase under future environmental change.

Herbivore Diversity Helps Maintain Arctic Tundra Diversity

A long-term experiment in southwestern Greenland reveals that the presence of musk oxen and caribou helps stave off declines in Arctic tundra diversity brought on by climate change.

Accounting for behaviour in fine-scale habitat selection: A case study highlighting methodological intricacies.

Animal habitat selection-central in both theoretical and applied ecology-may depend on behavioural motivations such as foraging, predator avoidance, and thermoregulation. Step-selection functions (SSFs) enable assessment of fine-scale habitat selection as a function of an animal's movement capacities and spatiotemporal variation in extrinsic conditions. If animal location data can be associated with behaviour, SSFs are an intuitive approach to quantify behaviour-specific habitat selection. Fitting SSFs separately for distinct behavioural states helped to uncover state-specific selection patterns. However, while the definition of the availability domain has been highlighted as the most critical aspect of SSFs, the influence of accounting for behaviour in the use-availability design has not been quantified yet. Using a predator-free population of high-arctic muskoxen Ovibos moschatus as a case study, we aimed to evaluate how (1) defining behaviour-specific availability domains, and/or (2) fitting separate behaviour-specific models impacts (a) model structure, (b) estimated selection coefficients and (c) model predictive performance as opposed to behaviour-unspecific approaches. To do so, we first applied hidden Markov models to infer different behavioural modes (resting, foraging, relocating) from hourly GPS positions (19 individuals, 153-1062 observation days/animal). Using SSFs, we then compared behaviour-specific versus behaviour-unspecific habitat selection in relation to terrain features, vegetation and snow conditions. Our results show that incorporating behaviour into the definition of the availability domain primarily impacts model structure (i.e. variable selection), whereas fitting separate behaviour-specific models mainly influences selection strength. Behaviour-specific availability domains improved predictive performance for foraging and relocating models (i.e. behaviours with medium to large spatial displacement), but decreased performance for resting models. Thus, even for a predator-free population subject to only negligible interspecific competition and human disturbance we found that accounting for behaviour in SSFs impacted model structure, selection coefficients and predictive performance. Our results indicate that for robust inference, both a behaviour-specific availability domain and behaviour-specific model fitting should be explored, especially for populations where strong spatiotemporal selection trade-offs are expected. This is particularly critical if wildlife habitat preferences are estimated to inform management and conservation initiatives.

Metabarcoding of fecal pellets in wild muskox populations reveals negative relationships between microbiome and diet alpha diversity.

Microbiome diversity and diet composition concomitantly influence species health, fitness, immunity, and digestion. In environments where diet varies spatially and temporally, microbiome plasticity may promote rapid host adaptation to available resources. For northern ungulates in particular, metabarcoding of noninvasively collected fecal pellets presents unprecedented insights into their diverse ecological requirements and niches by clarifying the interrelationships of microbiomes, key to deriving nutrients, in context of altered forage availability in changing climates. Muskoxen (Ovibos moschatus) are Arctic-adapted species that experience fluctuating qualities and quantities of vegetation. Geography and seasonality have been noted to influence microbiome composition and diversity in muskoxen, yet it is unclear how their microbiomes intersect with diet. Following observations from other species, we hypothesized increasing diet diversity would result in higher microbiome diversity in muskoxen. We assessed diet composition in muskoxen using three common plant metabarcoding markers and explored correlations with microbiome data. Patterns of dietary diversity and composition were not fully concordant among the markers used, yet all reflected the primary consumption of willows and sedges. Individuals with similar diets had more similar microbiomes, yet in contrast to most literature, yielded negative relationships between microbiome and diet alpha diversity. This negative correlation may reflect the unique capacities of muskoxen to survive solely on high-fiber Arctic forage and provide insight into their resiliency to exploit changing dietary resources in a rapidly warming Arctic altering vegetation diversity.

Mammals of Yakutia: Changes in the understanding of the composition of the mammal fauna over the past 50 years and an Annotated List. Part 2. Carnivorous, Cetaceans, and Artiodactyls

This study presents data on the mammal fauna including Carnivora (5 families, 12 genera, and 17 species), Cetacea (2 families, 3 genera, and 3 species), and Artiodactyla (3 families, 8 genera, and 3 species). A total number of 28 species demonstarted an increase in the richness of these taxa over the past 50 years due to the introduction of one carnivorous species and two ungulate species. Among the latter, only the introduction of musk ox can be considered successful. In addition, sporadic occurrences of four species that were not part of the original fauna in Yakutia have been registered. The northern sea lion and bowhead whale can colonize marine regions of Yakutia, whereas the Asian badger can colonize its terrestrial regions if the current climate trend stays unchanged. The tiger is unlikely to survive the Yakutian conditions, due to both low temperatures and low density of the ungulates, which constitute the major part of its food supply. At present, the complete list of species that inhabit the terrestrial and marine areas of Yakutia includes 70 representatives of the Mammalia class. The major part of the mammalian fauna of the region consists of indigenous species, whereas the share of non-native species was only approximately 10%. The changes in the composition of the mammalian fauna over the last 50 years are connected with a better current knowledge of the regional fauna, introduction, and changes in the taxonomic rank of species and subspecies. Moreover, four new species were identified: Chiroptera (2), Insectivora (1), and Rodentia (1). Some clarifications have been made to the taxonomic rank of species and subspecies belonging to the genera Ochotona, Urocitellus, and Alexandromys (Microtus). The use of genetic approach can clarify the taxonomic rank of a number of species. More complete and precise data on the composition of the faunistic list, geographic ranges of these species can be obtained by covering the territorial gaps in the previous studies and additional research on understudied taxa, in particular chiropterans and marine mammals.

Next-generation sequencing approach to investigate genome variability of Parapoxvirus in Canadian muskoxen (Ovibos moschatus).

In 2016, the first orf virus, a double-stranded DNA (dsDNA) virus of the genus parapoxvirus, from a muskox was isolated on Victoria Island, Nunavut (NU), Canada. We used deep sequencing on DNA extracted from orf virus-positive tissues from wild muskoxen from locations on Victoria Island and the adjacent mainland. Orf virus sequence reads derived from four samples were nearly identical. The consensus sequences generated from pooled reads of MxOV comprises of a large contiguous sequence (contig) of 131,759bp and a smaller right terminal contig of 3552bp, containing all coding sequences identified as Parapoxvirus. Individual gene comparisons reveal that MxOV shares genetic characteristics with reference strains from both sheep and goat origin. Recombination analysis using Bootscan, MAXCHI, GENECONV, CHIMAERA, SISCAN, and RDP algorithms within the RDP4 software predicted recombination events in two virulence factors, and a large 3000bp segment of the MxOV genome. Partial B2L nucleotide sequences from strains around the world and other North American isolates were compared to MxOV using MUSCLE alignments and RAxML phylogenetic trees. MxOV was identical to our previously characterized isolate, and shared similarity with orf virus isolated from sheep and goats. The phylogenetic grouping of partial B2L nucleotide sequences did not follow the sample geographic distribution. More full genomes of orf virus, or at least full B2L gene squences, in wildlife are needed especially in North America to better understand the epidemiology of the disease in muskoxen.

Diet flexibility of wolves and black bears in the range of migratory caribou

AbstractThe diet of predators can be highly variable, which is exemplified by their ability to acclimate to a wide range of ecological conditions. Such flexibility in foraging may be a key aspect of their performance in unpredictable environments such as at the edge of the range of a species or where food availability varies greatly in time and space. Gaining information on the diets of predators under such conditions could foster our comprehension of their ecological flexibility and the potential role of predation on the population dynamics of prey. We determined the diet of wolves (Canis lupus) and black bears (Ursus americanus) in northern Québec and Labrador (Canada) within the range of two migratory caribou (Rangifer tarandus) herds: the high-abundance Rivière-aux-Feuilles herd (RFH) and low-abundance Rivière-George herd (RGH). Worldwide, decline in caribou populations has become a concern, stressing the need to better understand the factors involved in these declines, including predation. In northern Québec (RFH range), caribou was the primary year-round prey of wolves while moose (Alces alces) and muskoxen (Ovibos moschatus) were consumed in some sectors. The diet of wolves in northern Labrador (RGH range) varied seasonally, with caribou, moose, and fish as main prey during different periods throughout the year. Black bear diets varied seasonally and regionally. Among the foods we analyzed, caribou was the main source of animal protein for bears in northern Québec and northern Labrador, except during a high abundance of Ungava collared lemming (Dicrostonyx hudsonius). Only bears in northern Québec ate caribou during late summer/fall. Our results highlight the diet flexibility of wolves and black bears in northern food webs, and how their diets change in relation to the distribution and abundance of prey. Our results will help quantify the potential impact of these predators on prey populations in northern systems.