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

The cost of a prickly diet: incidents of porcupine (Erethizon dorsatum) quills embedded in Wolverine (Gulo gulo)

The occurrence of North American Porcupine (Erethizon dorsatum) quills embedded in wild carnivores and domestic dogs is not rare; however, the prevalence of this occurrence and its consequences in wildlife are largely unknown. We examined 569 trapper-submitted Wolverine (Gulo gulo) carcasses for embedded porcupine quills. We observed quills in 4.6% of the wolverines, including all sex and age classes. We found quills throughout the body, and, in most cases, injury was not apparent. Observed complications, however, included bone proliferation and tissue damage to internal organs. Our data show that the occurrence of porcupine quills in Wolverine is not rare and demonstrate that, in a few cases, serious injuries may result from migrating quills

Influence of habitat type on the decay and disappearance of elk Cervus canadensis pellets in boreal forest of northwestern Canada

Fecal pellet counts are often used to assess trends in ungulate population size and habitat use. However, various factors may influence the physical decay and disappearance of pellets, where disappearance may be a result of physical decay and other factors (e.g. trampling, scattering and concealment by vegetation). Knowing pellet decay and disappearance rates in different habitats is a prerequisite to acquiring reliable information from pellet counts. We examined elk Cervus canadensis pellet decay and disappearance of individual pellets and pellet groups in six habitats in the boreal forest of northwestern Canada. We monitored 120 pellet groups deposited in May 2008 at 4, 12, 16 and 28 month intervals (i.e. the end of each of three plant growing seasons) to assess differences in physical decay and disappearance. Pellet decay and disappearance varied among habitats. In moist habitats, pellets showed little sign of decay by the end of our study, likely due to a short plant growing season. In drier, open habitat types, pellet decay was more rapid, likely due to exposure to sun and wind. By the end of our study, the percent of pellets remaining varied from a 14–82% among the sampled habitats. Pellets in moist forest habitats had the lowest decay rates but the highest disappearance rates, whereas those in dry, grassland sites had the highest decay, but the lowest disappearance rates. Our study further demonstrates that ungulate pellet decay and disappearance may differ substantially among habitats, which has important implications for the design of ungulate monitoring programs that utilize pellet counts. We conclude by recommending that fecal accumulation rate (FAR) methods are likely more appropriate in our study area than fecal standing crop (FSC) methods for estimating elk density, because FAR methods are less prone to biases associated with differential pellet decay and disappearance among habitats

New records of the Ogilvie Mountains Collared Lemming (Dicrostonyx nunatakensis) in central Yukon

The Ogilvie Mountain Collared Lemming (Dicrostonyx nunatakensis Youngman, 1967), reported only from the Ogilvie Mountains of central Yukon, is among the least known mammals in Canada. It was first discovered in 1961 and, since then, only 13 specimens had been collected, all from one mountain, in central Yukon. We conducted a targeted survey to determine the distribution of the species by trapping areas of apparently suitable habitat on 12 mountains within 40 km of the known location. Many of our traps were disabled by other mammals; however, we captured three Ogilvie Mountain Collared Lemmings on two mountains 25.9 km and 29.6 km from the original location. Our findings suggest that this lemming may be more widely distributed than indicated by earlier specimens. We suggest further surveys to delineate the range of the Ogilvie Mountain Collared Lemming

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

Diet and landscape characteristics drive spatial patterns of mercury accumulation in a high-latitude terrestrial carnivore.

Limited information exists on mercury concentrations and environmental drivers of mercury bioaccumulation in high latitude terrestrial carnivores. Spatial patterns of mercury concentrations in wolverine (Gulo gulo, n = 419) were assessed across a 1,600,000 km2 study area in relation to landscape, climate, diet and biological factors in Arctic and boreal biomes of western Canada. Hydrogen stable isotope ratios were measured in wolverine hair from a subset of 80 animals to assess the spatial scale for characterizing environmental conditions of their habitat. Habitat characteristics were determined using GIS methods and raster datasets at two scales, the collection location point and a 150 km radius buffer, which was selected based on results of a correlation analysis between hydrogen stable isotopes in precipitation and wolverine hair. Total mercury concentrations in wolverine muscle ranged >2 orders of magnitude from 0.01 to 5.72 μg/g dry weight and varied geographically, with the highest concentrations in the Northwest Territories followed by Nunavut and Yukon. Regression models at both spatial scales indicated diet (based on nitrogen stable isotope ratios) was the strongest explanatory variable of mercury concentrations in wolverine, with smaller though statistically significant contributions from landscape variables (soil organic carbon, percent cover of wet area, percent cover of perennial snow-ice) and distance to the Arctic Ocean coast. The carbon and nitrogen stable isotope ratios of wolverine muscle suggested greater mercury bioaccumulation could be associated with feeding on marine biota in coastal habitats. Landscape variables identified in the modelling may reflect habitat conditions which support enhanced methylmercury transfer to terrestrial biota. Spatially-explicit estimates of wet atmospheric deposition were positively correlated with wolverine mercury concentrations but this variable was not selected in the final regression models. These landscape patterns provide a basis for further research on underlying processes enhancing methylmercury uptake in high latitude terrestrial food webs