scholarly journals Spring food habits of Wolverine (Gulo gulo) in the Colville River watershed, Alaska

2019 ◽  
Vol 132 (3) ◽  
pp. 268-278
Author(s):  
Ross R. Dorendorf ◽  
Kelly J. Sivy ◽  
Martin D. Robards ◽  
Tom W. Glass ◽  
Kristine L. Pilgrim
Keyword(s):  
Ground Squirrel ◽  
Prey Species ◽  
Castor Canadensis ◽  
North Slope ◽  
Arctic Ground Squirrel ◽  
Species Identity ◽  
Prey Category ◽  
Gulo Gulo ◽  
Diet Diversity ◽  
The North

Wolverines (Gulo gulo) are relatively abundant on the North Slope of Alaska, an Arctic ecosystem dominated by tundra habitats that run north from the Brooks Range across a wide coastal plain to the Beaufort Sea. The region contains a range of potential Wolverine prey species, including ungulates (Caribou [Rangifer tarandus], Moose [Alces americanus]), Arctic Ground Squirrel (Urocitellus parryii), and both Soricidae and Cricetidae species. The seasonal composition of these, and other prey species, in the Wolverines’ diet is not well understood. We collected Wolverine scats during spring (March–May) on the North Slope while tracking animals from snowmobiles and with helicopters that visited areas identified as of interest during ground surveys or using global positioning system collared animals. We analyzed prey remains in 48 scat samples based on hair, bone, and other prey fragments. We then calculated frequency of occurrence, percentage of occurrence, and weighted percent volume for each major prey category detected. We confirmed species identity of scats as Wolverine by amplifying the control region of the mitochondrial DNA. We estimated spring diet diversity and richness based on nine major prey categories detected in scats. Ungulates and cricetids together constituted 69% of the Wolverines’ spring diet, with Snowshoe Hare (Lepus americanus) constituting 9%, fox (Vulpes spp.) 6%, Arctic Ground Squirrel 2%, birds 2%, American Beaver (Castor canadensis) less than 1%, and unknown 6%.

scholarly journals Comparison of mechanical sorting and DNA metabarcoding for diet analysis with degraded wolf scats

2019 ◽  
Author(s):  
Aimee Massey ◽  
Gretchen Roffler ◽  
Tessa Vermeul ◽  
Jennifer Allen ◽  
Taal Levi
Keyword(s):  
Dna Sequences ◽  
Rare Species ◽  
Prey Species ◽  
Castor Canadensis ◽  
Black Bear ◽  
Diet Analysis ◽  
High Rate ◽  
Diet Diversity ◽  
Full Diet ◽  
Dna Metabarcoding

AbstractDNA metabarcoding has become a powerful technique for identifying species and profiling biodiversity with the potential to improve efficiency, reveal rare prey species, and correct mistaken identification error in diet studies. However, the extent to which molecular approaches agree with traditional approaches is unknown for many species. Here, we compare diets from wolf scats profiled using both mechanical sorting and metabarcoding of amplified vertebrate DNA sequences. Our objectives were: (1) compare findings from mechanical sorting and metabarcoding as a method of diet profiling and (2) use results to better understand diets of wolves on Prince of Wales Island, a population of conservation concern. We predicted metabarcoding would reveal both higher diversity of prey and identify rare species that are overlooked with mechanical sorting. We also posited that the relative contribution of Sitka black-tailed deer (Odocoileus hemionus sitkensis) and beaver (Castor canadensis) would be overestimated with mechanical sorting methods because of the failure to account for the full diet diversity of these wolves. We found that there was substantial overlap in the diets revealed using both methods, indicating that deer, beaver, and black bear (Ursus americanus) were the primary prey species. However, there was a large discrepancy in the occurrence of beaver in scats (54% and 24% from mechanical sorting and metabarcoding, respectively) explained by the high rate of false positives with mechanical sorting methods. Metabarcoding revealed more diet diversity than mechanical sorting, thus supporting our initial predictions. Prince of Wales Island wolves appear to have a more diverse diet with greater occurrence of rare species than previously described including 14 prey species that contribute to wolf diet. Metabarcoding is an effective method for profiling carnivore diet and enhances our knowledge concerning the full diversity of wolf diets, even in the extremely wet conditions of southeast Alaska, which can lead to DNA degradation. Given the increasingly efficient and cost-effective nature of collecting eDNA, we recommend incorporating these molecular methods into field-based projects to further examine questions related to increased use of alternate prey coinciding with changes in abundance of primary prey and habitat alteration.

Geologic framework of the "North Slope" petroleum province

1969 ◽  
Author(s):  
George Gryc ◽  
Irvin L. Tailleur ◽  
William Peters Brosge
Keyword(s):  
North Slope ◽  
The North

Dispersive noise removal in t-x space: Application to Arctic data

Geophysics ◽  
1988 ◽  
Vol 53 (3) ◽  
pp. 346-358 ◽  
Author(s):  
Greg Beresford‐Smith ◽  
Rolf N. Rango
Keyword(s):  
Signal To Noise Ratio ◽  
Noise Analysis ◽  
Noise Removal ◽  
North Slope ◽  
Frequency Bandwidth ◽  
The North ◽  
North Slope Of Alaska ◽  
Seismic Records ◽  
Time Offset ◽  
Undersampled Data

Strongly dispersive noise from surface waves can be attenuated on seismic records by Flexfil, a new prestack process which uses wavelet spreading rather than velocity as the criterion for noise discrimination. The process comprises three steps: trace‐by‐trace compression to collapse the noise to a narrow fan in time‐offset (t-x) space; muting of the noise in this narrow fan; and inverse compression to recompress the reflection signals. The process will work on spatially undersampled data. The compression is accomplished by a frequency‐domain, linear operator which is independent of trace offset. This operator is the basis of a robust method of dispersion estimation. A flexural ice wave occurs on data recorded on floating ice in the near offshore of the North Slope of Alaska. It is both highly dispersed and of broad frequency bandwidth. Application of Flexfil to these data can increase the signal‐to‐noise ratio up to 20 dB. A noise analysis obtained from a microspread record is ideal to use for dispersion estimation. Production seismic records can also be used for dispersion estimation, with less accurate results. The method applied to field data examples from Alaska demonstrates significant improvement in data quality, especially in the shallow section.

Temperature and the Regulation of Enzyme Activity in the Hibernator. Isoenzymes of Liver Pyruvate Kinase from the Hibernating and Non-hibernating Arctic Ground Squirrel

1974 ◽  
Vol 52 (10) ◽  
pp. 894-902 ◽  
Author(s):  
Hans W. Behrisch
Keyword(s):  
Molecular Weight ◽  
Pyruvate Kinase ◽  
Wide Temperature Range ◽  
Ground Squirrel ◽  
Energy Charge ◽  
High Energy ◽  
Ground Squirrels ◽  
The Arctic ◽  
Arctic Ground Squirrel ◽  
Temperature Range

Liver of the hibernating (H) Arctic ground squirrel (Citellus undulatus) contains a single species of pyruvate kinase (PyK) that is distinct from the single isoenzyme of pyK observed in the non-hibernating (NH) ground squirrel, which has been previously described (Behrisch &Johnson (1974) Can. J. Biochem. 52, 547–559). The H-PyK has a pI value of 5.7 and a molecular weight of 241 000 – 243 000. Affinity of the H-PyK for the substrates phosphoenolpyruvate (PEP) and ADP is not affected by changing temperature. It is argued that this stability of the apparent Km's for substrate over a wide temperature range permits the hibernator to take advantage of the Q10 effect in maintaining a low rate of the PyK reaction. Similarly, affinity of H-PyK for the allosteric activator fructose-1,6-phosphate (FDP) and the inhibitor ATP is also conspicuously independent of temperature, suggesting a fine stoichiometry in the relative concentrations of the regulatory ligands in control of H-PyK over a wide temperature range. Further, affinity of H-PyK for the inhibitor ATP is about three- to fourfold lower than that of the NH-PyK, a condition that would favor the maintenance of a high energy charge in the hibernating liver cell. ATP apparently inhibits PyK by causing a dissociation of the enzyme molecule into two "halves" of about 110 000 molecular weight each. This dissociation is offset and reversed by FDP. Removal of the ATP by dialysis does not of itself result in a reassociation of the PyK "halves"; FDP and/or the substrates are required for the two subunits of PyK to reassociate. As the apparent Ki of H-PyK for ATP is higher than that of NH-PyK, substantially higher concentrations of ATP are required to effect the dissociation of H-PyK. Similarly, elevated concentrations of FDP are required to offset the ATP-caused dissociation of the H-PyK.Hibernating Arctic ground squirrels that are preparing to emerge finally from the hibernating state already possess substantial activities of the NH-PyK isoenzyme. This suggests that the animal "anticipates" its transition from one metabolic state from another. On the basis of these data a formal mechanism is proposed for the regulation of liver PyK in the Arctic ground squirrel in both the non-hibernating and hibernating states.

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