Population survey of Peary caribou (Rangifer tarandus pearyi) and muskoxen (Ovibos moschatus) on Banks Island, Northwest Territories, July 2010

We conducted a systematic aerial transect survey of Peary caribou (Rangifer tarandus pearyi) and muskoxen (Ovibus moschatus) on Banks Island, Northwest Territories, in July 2010. The population estimate of adult Peary caribou was 1097 ± 343 (95% Confidence Interval: CI), which is not significantly different from the 2005 estimate of 929 ± 289 (95% CI; P < 0.05). The current number, however, is a 4- to 9-fold decrease since the 1980s. The adult muskoxen population estimate was 36 676 ± 4031 (95% CI), which is significantly lower than the 2005 estimate of 47 209 ± 3997 (95% CI; P < 0.05)

Recent Hybridization between a Polar Bear and Grizzly Bears in the Canadian Arctic

Grizzly bears have recently become more common on the Arctic Islands in the Inuvialuit Settlement Region, concurrently with a period of environmental change. Over the last decade, grizzly bear – polar bear hybrids have been confirmed within this region, triggering extensive discussion and speculation regarding the impact of hybridization on the parent species. Through harvests, sightings, and captures, we document an increase in the presence of grizzly bears and combine field observations of hybrids with genetic analysis and parentage analysis to identify four first-generation (F1) hybrids and four offspring of F1 hybrids and grizzly bears (backcross-to-grizzly-bear individuals). We trace these eight hybrid individuals to a single female polar bear who mated with two grizzly bears. We sampled one of her mates on the sea ice in the High Arctic and deduced the genotype of the other from his five offspring. The two male grizzly bears are sires of both the F1 generation and the backcross-to-grizzly-bear generation. So what initially appeared to be a sudden spate of hybridization in the western Canadian Arctic originated with the unusual mating between three non-hybrid parents. The breakdown of species barriers may start with atypical mating preferences of select individuals; however, the story we present can be traced to a single female polar bear who, along with three of her known F1 offspring, has been killed.La présence du grizzli se fait plus courante dans l’archipel Arctique de la région désignée des Inuvialuit depuis un certain temps, ce qui coïncide avec une période de changement environnemental. Ces dix dernières années, la présence d’ours polaires-grizzlis hybrides a été confirmée dans cette région, ce qui a déclenché d’importantes discussions et hypothèses relativement aux incidences de l’hybridation sur les espèces apparentées. Au moyen de récoltes, d’observations et de captures, nous avons documenté l’augmentation de la présence de grizzlis, alliées à des observations d’hybrides sur le terrain avec analyse génétique et analyse de parenté afin d’identifier quatre hybrides de première génération (F1) et quatre descendants d’hybrides F1 et de grizzlis (individus issus de rétrocroisements avec un grizzli). Nous faisons remonter ces huit hybrides à une seule ourse polaire qui s’est accouplée avec deux grizzlis. Nous avons prélevé un échantillon d’un de ses compagnons sur la glace de mer de l’Extrême-Arctique et avons déduit le génotype de l’autre à partir de ses cinq descendants. Les deux grizzlis mâles sont des géniteurs de la génération F1 et de la génération du rétrocroisement avec un grizzli. Donc, ce qui semblait être, au début, une montée soudaine d’hybridation dans l’ouest de l’Arctique canadien est attribuable à l’accouplement inhabituel de trois parents non hybrides. La rupture des obstacles auxquels les espèces font face pourrait commencer par les préférences d’accouplement atypiques de certains individus. Toutefois, la situation dont il est ici question remonte à une seule ourse polaire qui a été tuée, avec trois de ses descendants connus de la génération F1

Long-Distance Movement of a Female Polar Bear from Canada to Russia

Polar bears (Ursus maritimus) display fidelity to large geographic regions, and their movements are influenced by sea ice distribution. Polar bear subpopulations are moderately distinct from one another, and long-distance movements between subpopulations are rare. We describe and analyze the movements of a female polar bear tracked by satellite telemetry from spring 2009 for 798 days. This female traveled an exceptionally long distance (totaling 11 686 km) from the sea ice off the Yukon Territory, Canada (Southern Beaufort Sea subpopulation) to Wrangel Island, Russia (Chukchi Sea subpopulation). In comparison to other polar bears in this study, this bear traveled farther, moved faster, and had a much larger home range in the first year. Furthermore, the calculation of the home range size by two different methods demonstrated that the commonly used minimum convex polygon method overestimated the home range compared to the less biased Brownian bridge movement model. This female’s long-distance movement was unusual and provides additional evidence for gene flow between subpopulations. Monitoring polar bear movements is useful to track such events, which is especially important at present because sea ice loss due to climate change can affect subpopulation boundaries and influence management.L’ours polaire (Ursus maritimus) démontre sa fidélité à de grandes régions géographiques, et ses déplacements subissent l’influence de la répartition de la glace de mer. Les sous-populations d’ours polaires sont modérément distinctes les unes des autres, et les déplacements sur de longues distances entre les sous-populations sont rares. Nous décrivons et analysons les déplacements d’une ourse polaire suivie par télémétrie satellitaire pendant 798 jours à compter du printemps 2009. Cette femelle s’est déplacée sur une distance exceptionnellement longue (11 686 km au total) depuis la glace de mer au large du territoire du Yukon, au Canada (sous-population du sud de la mer de Beaufort) jusqu’à l’île Wrangel, en Russie (sous-population de la mer des Tchouktches). Comparativement à d’autres ours polaires visés par cette étude, cette ourse s’est déplacée plus loin et plus vite, et elle avait un domaine vital beaucoup plus vaste au cours de sa première année. De plus, le calcul de la taille de son domaine vital effectué au moyen de deux méthodes différentes a permis de constater que la méthode fréquemment utilisée du polygone convexe minimum donnait lieu à la surestimation du domaine vital comparativement au modèle de mouvement moins faussé du pont brownien. Le déplacement de cette ourse sur de longues distances était inhabituel et il permet d’obtenir des preuves supplémentaires au sujet du flux génétique entre les sous-populations. La surveillance des déplacements des ours polaires est utile dans le cadre du suivi de tels événements, ce qui est particulièrement important en ce moment, car la perte de glace de mer attribuable au changement climatique peut avoir des effets sur les frontières des sous-populations et la gestion des influences

Trichinella pseudospiralis in a wolverine (Gulo gulo) from the Canadian North

Species of Trichinella are a globally distributed assemblage of nematodes, often with distinct host ranges, which include people, domestic, and wild animals. Trichinella spp. are important in northern Canada, where dietary habits of people and methods of meat preparation (drying, smoking, fermenting as well as raw) increase the risk posed by these foodborne zoonotic parasites. Outbreaks in the arctic and subarctic regions of Canada and the United States are generally attributed to T. nativa (T2) or the T6 genotype, when genetic characterization is performed. We report the discovery of Trichinella pseudospiralis (T4), a non-encapsulated species, in a wolverine (Gulo gulo) from the Northwest Territories of Canada. This parasite has been previously reported elsewhere from both mammals and carnivorous birds, but our findings represent new host and geographic records for T. pseu- dospiralis. Multiplex PCR and sequencing of fragments of Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetically, Canadian isolates linked with each other and others derived from Palearctic or Neotropical regions, but not elsewhere in the Nearctic (continental USA). We suggest that mi- gratory birds might have played a role in the dispersal of this pathogen 1000\u27s of km to northwestern Canada. Wolverines are not typically consumed by humans, and thus should not pose a direct food safety risk for tri- chinellosis. However, the current finding suggests that they may serve as an indicator of a broader distribution for T. pseudospiralis. Along with infection risk already recognized for T. nativa and Trichinella T6, our observa- tions emphasize the need for further studies using molecular diagnostics and alternative methods to clarify if this is a solitary case, or if T. pseudospiralis and other freeze susceptible species of Trichinella (such as T. spiralis) circulate more broadly in wildlife in Canada, and elsewhere

Hiding in plain sight: discovery and phylogeography of a cryptic species of Trichinella (Nematoda: Trichinellidae) in wolverine (Gulo gulo)

Understanding parasite diversity and distribution is essential in managing the potential impact of para- sitic diseases in animals and people. Imperfect diagnostic methods, however, may conceal cryptic species. Here, we report the discovery and phylogeography of a previously unrecognized species of Trichinella in wolverine (Gulo gulo) from northwestern Canada that was indistinguishable from T. nativa using the stan- dard multiplex PCR assay based on the expansion segment 5 (ESV) of ribosomal DNA. The novel genotype, designated as T13, was discovered when sequencing the mitochondrial genome. Phylogenetic analyses of the mitochondrial genome and of 15 concatenated single-copy orthologs of nuclear DNA indicated a com- mon ancestor for the encapsulated clade is shared by a subclade containing Trichinella spiralis and Trichinella nelsoni, and a subclade containing T13 and remaining taxa: T12 + (T2 + T6) + [(T5 + T9) + (T 3 + T8)]. Of 95 individual hosts from 12 species of mammalian carnivores from northwestern Canada from which larvae were identified as T. nativa on multiplex PCR, only wolverines were infected with T13 (14 of 42 individuals). These infections were single or mixed with T. nativa and/or T6. Visual examination and motility testing confirmed that T13 is encapsulated and likely freeze-tolerant. We developed a new Polymerase Chain Reaction-Restriction Fragment Length Polymorphism which unequivocally distinguishes between T13 and T. nativa. We propose Trichinella chanchalensis n. sp. for T13, based on significant genetic divergence from other species of Trichinella and broad-based sampling of the Trichinella genome. Exploration of Alaskan and Siberian isolates may contribute to further resolution of a phylogeo- graphically complex history for species of Trichinella across Beringia, including Trichinella chanchalensis n. sp. (T13

Trichinella pseudospiralis in a wolverine (Gulo gulo) from the Canadian North

Species of Trichinella are a globally distributed assemblage of nematodes, often with distinct host ranges, which include people, domestic, and wild animals. Trichinella spp. are important in northern Canada, where dietary habits of people and methods of meat preparation (drying, smoking, fermenting as well as raw) increase the risk posed by these foodborne zoonotic parasites. Outbreaks in the arctic and subarctic regions of Canada and the United States are generally attributed to T. nativa (T2) or the T6 genotype, when genetic characterization is performed. We report the discovery of Trichinella pseudospiralis (T4), a non-encapsulated species, in a wolverine (Gulo gulo) from the Northwest Territories of Canada. This parasite has been previously reported elsewhere from both mammals and carnivorous birds, but our findings represent new host and geographic records for T. pseu- dospiralis. Multiplex PCR and sequencing of fragments of Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetically, Canadian isolates linked with each other and others derived from Palearctic or Neotropical regions, but not elsewhere in the Nearctic (continental USA). We suggest that mi- gratory birds might have played a role in the dispersal of this pathogen 1000\u27s of km to northwestern Canada. Wolverines are not typically consumed by humans, and thus should not pose a direct food safety risk for tri- chinellosis. However, the current finding suggests that they may serve as an indicator of a broader distribution for T. pseudospiralis. Along with infection risk already recognized for T. nativa and Trichinella T6, our observa- tions emphasize the need for further studies using molecular diagnostics and alternative methods to clarify if this is a solitary case, or if T. pseudospiralis and other freeze susceptible species of Trichinella (such as T. spiralis) circulate more broadly in wildlife in Canada, and elsewhere

Hiding in plain sight: discovery and phylogeography of a cryptic species of Trichinella (Nematoda: Trichinellidae) in wolverine (Gulo gulo)

Understanding parasite diversity and distribution is essential in managing the potential impact of para- sitic diseases in animals and people. Imperfect diagnostic methods, however, may conceal cryptic species. Here, we report the discovery and phylogeography of a previously unrecognized species of Trichinella in wolverine (Gulo gulo) from northwestern Canada that was indistinguishable from T. nativa using the stan- dard multiplex PCR assay based on the expansion segment 5 (ESV) of ribosomal DNA. The novel genotype, designated as T13, was discovered when sequencing the mitochondrial genome. Phylogenetic analyses of the mitochondrial genome and of 15 concatenated single-copy orthologs of nuclear DNA indicated a com- mon ancestor for the encapsulated clade is shared by a subclade containing Trichinella spiralis and Trichinella nelsoni, and a subclade containing T13 and remaining taxa: T12 + (T2 + T6) + [(T5 + T9) + (T 3 + T8)]. Of 95 individual hosts from 12 species of mammalian carnivores from northwestern Canada from which larvae were identified as T. nativa on multiplex PCR, only wolverines were infected with T13 (14 of 42 individuals). These infections were single or mixed with T. nativa and/or T6. Visual examination and motility testing confirmed that T13 is encapsulated and likely freeze-tolerant. We developed a new Polymerase Chain Reaction-Restriction Fragment Length Polymorphism which unequivocally distinguishes between T13 and T. nativa. We propose Trichinella chanchalensis n. sp. for T13, based on significant genetic divergence from other species of Trichinella and broad-based sampling of the Trichinella genome. Exploration of Alaskan and Siberian isolates may contribute to further resolution of a phylogeo- graphically complex history for species of Trichinella across Beringia, including Trichinella chanchalensis n. sp. (T13

Intestinal parasites of wolves (Canis lupus L. 1758) in northern and western Canada

Gray wolves (Canis lupus L., 1758) are mobile opportunistic predators that can be infected by a wide range of parasites, with many acquired via predator-prey relationships. Historically, many of these parasites were identified only to genus or family, but genetic tools now enable identification of parasite fauna to species and beyond. We examined 191 intestines from wolves harvested for other purposes from regions in the Northwest Territories, British Columbia, Saskatchewan, and Manitoba. Adult helminths were collected from intestinal contents for morphological and molecular identification, and for a subset of wolves, fecal samples were also analyzed to detect helminth eggs and protozoan (oo)cysts. Using both detection methods, we found that 83% of 191 intestines contained one or more parasite species, including cestodes (Taenia spp., Echinococcus spp., and Diphyllobothrium sp.), nematodes (Uncinaria stenocephala, Trichuris spp., Physaloptera spp., and Toxascaris leonina), a trematode (Alaria sp.), and protozoa (Sarcocystis spp., Giardia spp., and Cryptosporidium spp.). Molecular characterization identified one species of Diphyllobothrium (D. latum), three species of Taenia (T. krabbei, T. hydatigena, and T. multiceps), and two Giardia assemblages (B and C). These results demonstrate the diverse diet of wolves, and illustrate the possibility of parasite spillover among wildlife, domestic animals, and people.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author