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"Wolverines"
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Rakkety Tam
Two warrior squirrels lead the battle against Gulo, a bloodthirsty wolverine who will stop at nothing to recover the Walking Stone that will give him the authority to rule the lands of ice beyond the Great Sea.
Book
Diversity of the MHC class II DRB gene in the wolverine
The wolverine (Gulo gulo) in Finland has undergone significant population declines in the past. Since major histocompatibility complex (MHC) genes encode proteins involved in pathogen recognition, the diversity of these genes provides insights into the immunological fitness of regional populations. We sequenced 862 amplicons (242 bp) of MHC class II DRB exon 2 from 32 Finnish wolverines and identified 11 functional alleles and three pseudogenes. A molecular phylogenetic analysis indicated trans-species polymorphism, and PAML and MEME analyses indicated positive selection, suggesting that the Finnish wolverine DRB genes have evolved under balancing and positive selection. In contrast to DRB gene analyses in other species, allele frequencies in the Finnish wolverines clearly indicated the existence of two regional subpopulations, congruent with previous studies based on neutral genetic markers. In the Finnish wolverine, rapid population declines in the past have promoted genetic drift, resulting in a lower genetic diversity of DRB loci, including fewer alleles and positively selected sites, than other mustelid species analyzed previously. Our data suggest that the MHC region in the Finnish wolverine population was likely affected by a recent bottleneck.
Journal Article
Wolverines
\"Superhero and comic book force? Sure, but also a real-life animal! Find out in this Level 3 Reader how fierce wolverines, who are expert survivors, can be even more fantastic than those in movies and graphic novels. Journey through harsh cold and rugged mountain ranges to see how wolverines take down prey, raise their young, and live in one of the world's harshest environments. Learn how their bodies adapt for survival and about its challenges in a warming world. National Geographic Readers' expert-vetted text, along with brilliant images and a fun approach to reading have proved to be a winning formula with kids, parents and educators. Level 3 text provides accessible, yet wide-ranging, information for fluent readers. Each reader includes text written by an experienced, skilled children's books author, a photo glossary, and interactive features in which kids get to reinforce what they've learned in the book\"-- Provided by publisher.
Book
Evaluating the accuracy of wolverine identification from photographs of snow tracks by expert observers in North America
North American wolverines Gulo gulo are a species of conservation concern across much of their range. The remote and rugged terrain they occupy has led to the development of various remote detection methods. While visual identification of wolverine tracks has a long history of use, it has recently been considered less reliable than other remote identification methods. We evaluated the ability of 29 observers to identify wolverine from photographs of snow tracks. Each observer reviewed 99 observations: 48 of wolverine and 51 of species whose tracks are confusable for wolverine. The identification of each observation used was independently verified by visual observation of the animal that made the tracks or genetic samples collected from the tracks that confirmed field identification. We compared the performance of observers based on their demographic characteristics and the details present in each observation. Observers demonstrated a low false-positive error rate, cumulatively misidentifying observations of other species as definitively wolverine less than 1% of the time. The only clear demographic predictor of an observer's skill was their level of tracking certification via Cybertracker Conservation. Higher certification levels produced more positive detections of wolverine than did low or no certification. Observations with clear details in individual tracks produced the highest rate of positive detections. Depending on the level of certainty expected, observers detected 75-88% of wolverine observations that contained clear details in the tracks and clear track patterns, with a false-positive error rate of 1.1-3.5%. While the error rate did not increase, positive detections occurred less in observations without morphological details in individual tracks or clear track patterns. Observers called these 'unknown' more often. Our results indicate that observers can consistently distinguish wolverine from other species from photographs of snow tracks and refute the assumption that visual track identification is inherently unreliable.
Journal Article
Spatiotemporally variable snow properties drive habitat use of an Arctic mesopredator
Climate change is rapidly altering the composition and availability of snow, with implications for snow-affected ecological processes, including reproduction, predation, habitat selection, and migration. How snowpack changes influence these ecological processes is mediated by physical snowpack properties, such as depth, density, hardness, and strength, each of which is in turn affected by climate change. Despite this, it remains difficult to obtain meaningful snow information relevant to the ecological processes of interest, precluding a mechanistic understanding of these effects. This problem is acute for species that rely on particular attributes of the subnivean space, for example depth, thermal resistance, and structural stability, for key life-history processes like reproduction, thermoregulation, and predation avoidance. We used a spatially explicit snow evolution model to investigate how habitat selection of a species that uses the subnivean space, the wolverine, is related to snow depth, snow density, and snow melt on Arctic tundra. We modeled these snow properties at a 10 m spatial and a daily temporal resolution for 3 years, and used integrated step selection analyses of GPS collar data from 21 wolverines to determine how these snow properties influenced habitat selection and movement. We found that wolverines selected deeper, denser snow, but only when it was not undergoing melt, bolstering the evidence that these snow properties are important to species that use the Arctic snowpack for subnivean resting sites and dens. We discuss the implications of these findings in the context of climate change impacts on subnivean species. species that use the Arctic snowpack for subnivean resting sites and dens. We discuss the implications of these findings in the context of climate change impacts on subnivean species.
Journal Article
Diversity of the MHC class II DRB gene in the wolverine (Carnivora: Mustelidae: Gulo gulo) in Finland
The wolverine ( Gulo gulo ) in Finland has undergone significant population declines in the past. Since major histocompatibility complex (MHC) genes encode proteins involved in pathogen recognition, the diversity of these genes provides insights into the immunological fitness of regional populations. We sequenced 862 amplicons (242 bp) of MHC class II DRB exon 2 from 32 Finnish wolverines and identified 11 functional alleles and three pseudogenes. A molecular phylogenetic analysis indicated trans-species polymorphism, and PAML and MEME analyses indicated positive selection, suggesting that the Finnish wolverine DRB genes have evolved under balancing and positive selection. In contrast to DRB gene analyses in other species, allele frequencies in the Finnish wolverines clearly indicated the existence of two regional subpopulations, congruent with previous studies based on neutral genetic markers. In the Finnish wolverine, rapid population declines in the past have promoted genetic drift, resulting in a lower genetic diversity of DRB loci, including fewer alleles and positively selected sites, than other mustelid species analyzed previously. Our data suggest that the MHC region in the Finnish wolverine population was likely affected by a recent bottleneck.
Journal Article
Dining with wolves: Are the rewards worth the risks?
Where wild populations of gray wolves ( Canis lupus ) occur in North America, common ravens ( Corvus corax ) and, in western regions, black-billed magpies ( Pica hudsonia ) (Family Corvidae), show up quickly at wolf kills and scavenge carcasses, often feeding near wolves. Ravens and magpies also visit wolf enclosures at gray wolf sanctuaries in Colorado, USA, and attempt to take food from wolves, but there is no information regarding how often they obtain food or are injured or killed. Working at the Colorado Wolf and Wildlife Center, Divide, Colorado, we asked whether ravens and magpies associate with gray wolves at feeding time; what proportions of ravens and magpies obtain food per enclosure; whether individual wolves react differently to the birds; and if the birds are harmed by interacting with wolves. We also examined the effects of food type, amount, and air temperature on bird numbers. We counted raven and magpie numbers in wolf enclosures and wolf and bird behaviors during daily feeding tours across 20 visits and within eight wolf enclosures per visit. Wolf reactions within each enclosure were categorized as chasing or ignoring birds or removing food. Cumulatively, across all dates and enclosures, 33% of ravens and 43% of magpies obtained food within each enclosure. Because birds were not individually marked, these percentages could be higher. Individual wolves differed in responses to ravens and magpies but most often ignored bird presence. We found no effect of food type on bird numbers but a trend in reward probability with greater food amount for ravens. There were, however, statistically significant negative relationships between daily maximum and average temperature and raven numbers, and significant positive relationships between daily minimum and average temperature and magpie numbers. We conclude that dining with wolves represented a successful foraging strategy with low risk to ravens and magpies.
Journal Article
Wolverines use spatial memory to plan efficient routes through rugged terrain
Background
To navigate, animals balance nearby perceptual cues, random search, and memory. Isolating the role of memory, however, remains difficult.
Methods
Here, we use a mechanistic movement model to do so, simulating animals responding solely to local perceptual cues (i.e., lacking memory) and comparing their paths with actual routes taken. By comparing route efficiency, we evaluate whether actual routes incorporate knowledge beyond the perceptual range (i.e., spatial memory).
Results
We show that wolverines (
Gulo gulo
) employ spatial memory to plan routes through a rugged, mountainous landscape. Furthermore, we find that wolverines most commonly plan routes to destinations 5.3–9.8 km ahead. We estimate that route-planning saves wolverines, on average, 19.3 kcal per 135 min of movement.
Conclusions
Our findings provide a template for evaluating how free-living animals recall the world beyond their perceptual range, offer a window into the cognitive mechanics underpinning navigation for this species, and support adding wolverines to the primate-dominated list of species with complex spatial memory.
Journal Article
On taming the effect of transcript level intra-condition count variation during differential expression analysis: A story of dogs, foxes and wolves
The evolution of RNA-seq technologies has yielded datasets of scientific value that are often generated as condition associated biological replicates within expression studies. With expanding data archives opportunity arises to augment replicate numbers when conditions of interest overlap. Despite correction procedures for estimating transcript abundance, a source of ambiguity is transcript level intra-condition count variation; as indicated by disjointed results between analysis tools. We present TVscript, a tool that removes reference-based transcripts associated with intra-condition count variation above specified thresholds and we explore the effects of such variation on differential expression analysis. Initially iterative differential expression analysis involving simulated counts, where levels of intra-condition variation and sets of over represented transcripts are explicitly specified, was performed. Then counts derived from inter- and intra-study data representing brain samples of dogs, wolves and foxes (wolves vs . dogs and aggressive vs . tame foxes) were used. For simulations, the sensitivity in detecting differentially expressed transcripts increased after removing hyper-variable transcripts, although at levels of intra-condition variation above 5% detection became unreliable. For real data, prior to applying TVscript, ≈20% of the transcripts identified as being differentially expressed were associated with high levels of intra-condition variation, an over representation relative to the reference set. As transcripts harbouring such variation were removed pre-analysis, a discordance from 26 to 40% in the lists of differentially expressed transcripts is observed when compared to those obtained using the non-filtered reference. The removal of transcripts possessing intra-condition variation values within (and above) the 97 th and 95 th percentiles, for wolves vs . dogs and aggressive vs . tame foxes, maximized the sensitivity in detecting differentially expressed transcripts as a result of alterations within gene-wise dispersion estimates. Through analysis of our real data the support for seven genes with potential for being involved with selection for tameness is provided. TVscript is available at: https://sourceforge.net/projects/tvscript/ .
Journal Article
High prevalence, intensity, and genetic diversity of Trichinella spp. in wolverine (Gulo gulo) from Yukon, Canada
Background
Species of
Trichinella
are globally important foodborne parasites infecting a number of domestic and wild vertebrates, including humans. Free-ranging carnivores can act as sentinel species for detection of
Trichinella
spp. Knowledge of the epidemiology of these parasites may help prevent
Trichinella
spp. infections in northern Canadian animals and people. Previous research on
Trichinella
spp. in wildlife from Yukon did not identify risk factors associated with infection, or the diversity and identity of species of
Trichinella
in regional circulation, based on geographically extensive sampling with large sample sizes.
Methods
In a cross-sectional study, we determined the prevalence, infection intensity, risk factors, and species or genotypes of
Trichinella
in wolverine (
Gulo gulo
) in two regions of Yukon, Canada, from 2013–2017. A double separatory funnel digestion method followed by mutiplex PCR and PCR-RFLP were used to recover and identify species of
Trichinella
, respectively.
Results
We found larvae of
Trichinella
in the tongues of 78% (95% CI 73–82) of 338 wolverine sampled. The odds of adult (≥ 2 years) and yearling (1 year) wolverine being
Trichinella
spp.-positive were four and two times higher, respectively, compared to juveniles (<1 year). The odds of
Trichinella
spp
.
presence were three times higher in wolverine from southeast than northwest Yukon. The mean intensity of infection was 22.6 ± 39 (SD, range 0.1–295) larvae per gram.
Trichinella
T6 was the predominant genotype (76%), followed by
T. nativa
(8%); mixed infections with
Trichinella
T6 and
T. nativa
(12%) were observed. In addition,
T. spiralis
was detected in one wolverine. Out of 22 isolates initially identified as
T. nativa
in multiplex PCR, 14 were analyzed by PCR-RFLP to distinguish them from
T. chanchalensis
, a recently discovered cryptic species, which cannot be distinguished from the
T. nativa
on multiplex PCR. Ten isolates were identified either as
T. chanchalensis
alone (
n
= 7), or mixed infection with
T. chanchalensis
and
T. nativa
(
n
= 2) or
T. chanchalensis
and
Trichinella
T6 (
n
= 1)].
Conclusions
Wolverine hosted high prevalence, high larval intensity, and multiple species of
Trichinella
, likely due to their scavenging habits, apex position in the food chain, and wide home range. Wolverine (especially adult males) should be considered as a sentinel species for surveys for
Trichinella
spp. across their distributional range.
Graphical Abstract
Journal Article