scholarly journals Observations of Nocturnal Hunting Behaviour of American Badgers, Taxidea taxus, in Southwestern Saskatchewan

2013 ◽  
Vol 126 (3) ◽  
pp. 226
Author(s):  
Gilbert Proulx ◽  
Neil MacKenzie

This study describes the nocturnal hunting behaviour of American Badgers (Taxidea taxus) in areas inhabited by Richardson’s Ground Squirrels (Urocitellus richardsonii) in southwestern Saskatchewan. Adult American Badgers searched for prey by zigzagging through clusters of Richardson’s Ground Squirrel burrows or by going back and forth between one enlarged Richardson’s Ground Squirrel burrow and other adjacent burrows. American Badgers’ movements were not random and they were oriented to encounter prey.

2020 ◽  
Vol 57 (7) ◽  
pp. 855-866
Author(s):  
Thomas C.A. Royle ◽  
Dongya Y. Yang ◽  
Jonathan C. Driver

Ancient DNA was extracted from 12 500 to 10 500 year old ground squirrel bones from Tse’K’wa, an archaeological site in the Peace River region of northeastern British Columbia, Canada. Analysis of mitochondrial DNA from seven individuals demonstrates that all are Urocitellus richardsonii (Richardson’s ground squirrel), a species not found in the region today. Phylogenetic and sequence analyses indicate these individuals share a previously undocumented mitochondrial control region haplotype that is most closely related to haplotypes observed in modern specimens from Saskatchewan and Montana. At the end of the Pleistocene these ground squirrels extended their range north and west into open vegetation communities that developed when ice sheets melted and glacial lakes drained. They were subsequently extirpated from the Peace River region when forests replaced earlier pioneering vegetation communities.


1983 ◽  
Vol 61 (2) ◽  
pp. 370-377 ◽  
Author(s):  
Richard J. Cawthorn ◽  
Gary A. Wobeser ◽  
Alvin A. Gajadhar

Sarcocystis campestris sp. n. (Protozoa: Sarcocystidae) is an heteroxenous coccidium with badgers (Taxidea taxus) as natural and experimental definitive hosts and Richardson's ground squirrels (Spermophilus richardsonii) as experimental intermediate hosts. Free sporocysts (10.2 × 8.0 μm with a large, round sporocyst residuum consisting of a single refractile granule), obtained from intestinal scrapings of badgers (carcasses frozen 2 years at −20 °C), were orally administered to juvenile Richardson's ground squirrels. Acute fatal sarcocystosis developed in some squirrels at 11–13 days postinoculation (p.i.). Meronts (second generation) were present 9–12 days p.i. in the vascular endothelium of many tissues (especially the lungs). Cysts developed in skeletal muscle, contained metrocytes (7 × 5 μm) 30 days p.i., and beginning 46 days p.i., bradyzoites (12.0 × 3.5 μm) were present. Cysts were macroscopic as early as 258 days p.i. Squirrel carcasses containing cysts (76 days p.i.) of S. campestris sp. n. were fed to Sarcocystis-free badgers. The prepatent period was 9 days and the patent period at least 13 days. Both badgers were ill early in the patent period and passed unformed feces during the patent period. Free sporocysts were 10.2 × 8.0 μm and each had an elongate sporocyst residuum containing numerous small refractile granules.


2016 ◽  
Vol 129 (4) ◽  
pp. 331 ◽  
Author(s):  
Levi J. Newediuk ◽  
Isobel Waters ◽  
James F. Hare

Although Richardson’s Ground Squirrels (Urocitellus richardsonii) are considered pests throughout their North American range, their impact on forage in Canadian aspen parkland has not been explored. We investigated the effect of Richardson’s Ground Squirrel density on forage quality and plant community composition in an intensely grazed cattle pasture in the aspen parkland region of Manitoba, Canada. We detected no significant differences in forage protein content or legume, grass, and litter biomass among ground squirrel density levels. However, ground squirrel density did influence the abundance of invasive and forage plant species; greater squirrel density reduced the prevalence of Smooth Brome (Bromus inermis Leysser) and Red Clover (Trifolium pratense L.) and increased the abundance of Quackgrass (Elymus repens (L.) Gould) and Black medick (Medicago lupulina L.). Plant community diversity also increased with ground squirrel density. There were no differences in soil bulk density or ammonia content among squirrel density levels; however, soil nitrate content was highest at low ground squirrel density. Changes in available soil nitrogen and relative abundances of forage species on this pasture may affect cattle diet by altering both the availability and quality of forage. Our findings highlight the need for further investigation of the role of Richardson’s Ground Squirrel on rangeland in the aspen parkland region to ascertain the generality of the effects documented in our study. Until such effects and their implications for cattle production are understood, land managers should refrain from exterminating colonies of Richardson’s Ground Squirrel.


Author(s):  
Ryan J Fisher ◽  
Ashley N. Vass ◽  
C. M. Somers ◽  
Ray G. Poulin

Richardson’s ground squirrel (Urocitellus richardsonii, Sabine 1822) is a widespread burrowing mammal on the Northern Great Plains. This species is a prominent prey item for a variety of predators, and its burrows provide important habitat for other wildlife; however, Richardson’s ground squirrel is also considered an economically damaging agricultural pest. Despite the ecological importance of Richardson’s ground squirrels and their status as pests, there are gaps in our knowledge about large-scale habitat associations for this species. In 2011 and 2012, we conducted 1840 road-side surveys in a 130,000-km2 area of southern Saskatchewan, Canada to understand which habitat features are associated with Richardson’s ground squirrel occurrence. Ground squirrels were observed on 8% of the surveys. Probability of ground squirrel occurrence was highest in areas with moderate amounts of grassland (approximately 30%), areas that were developed by humans (>30%), and had a high proportion of clay loam soils, presumably for burrowing. Our study highlights the importance of heterogeneous landscapes and that areas disturbed by humans may provide suitable vegetation structure for ground squirrels. This information can help to identify important habitat for species that rely on Richardson’s ground squirrels and identify areas where Richardson’s ground squirrels could come into conflict with agriculture.


2012 ◽  
Vol 126 (2) ◽  
pp. 148
Author(s):  
Gilbert Proulx

Heavy rains with strong winds in southwestern Saskatchewan from 20 to 29 May 2010 flooded fields where adult Richardson’s Ground Squirrels (Urocitellus richardsonii) had recently been live–trapped. Natural mortality rates in six marked populations (n = 11 to 29 animals) ranged from 9.1 to 42.9%. The mean mortality rate of populations (28.9%) was significantly greater than that estimated for four populations (8.5%) studied in April and May 2007 and 2008 during drought periods. This finding is in agreement with past studies on other ground squirrel species which showed that spring snowstorms and heavy rains caused an increase in natural mortality rates.


2020 ◽  
Vol 70 (6) ◽  
pp. 542-550
Author(s):  
Patrick N Nation

This paper presents a retrospective review of the postmortem findings in a colony of wild-caught ground squirrels used in medical research. The species included in this study were Richardson's ground squirrel Urocitellus richardsonii, Columbian ground squirrel Urocitellus columbianus and golden-mantled ground squirrel Callospermophilus lateralis. The pathologic findings in 160 ground squirrels from this colony demonstrated a wide variety of conditions, with chronic nephritis and hepatic adenomas being the most frequent overall. All animals with gross lesions of chronic interstitial nephritis had both glomerular and tubulointerstitial disease upon microscopic examination. As the first review of pathology in a research colony of ground squirrels. this study provides data for use in comparative studies about rodent diseases and important information for those who maintain such animals for research.


2015 ◽  
Vol 148 (2) ◽  
pp. 143-150 ◽  
Author(s):  
Matthew E.M. Yunik ◽  
Jane M. Waterman ◽  
Terry D. Galloway

AbstractLinognathoides laeviusculus (Grube) (Phthiraptera: Anoplura: Polyplacidae) is a louse found on holarctic ground squirrels but little is known about how the life history, physiology, and hibernation of the host influence its population dynamics. Two hundred and fourteen Richardson’s ground squirrels (Urocitellus richardsonii (Sabine); Rodentia: Sciuridae) were trapped over the summer of 2010, and the age, sex, and mass of all euthanised squirrels were recorded. Squirrels were hand-washed to remove lice, which were then identified to species, stage of development, and sex. Linognathoides laeviusculus was the only louse collected. In total, 5057 lice were collected with 63.6% of the squirrels infested at a mean intensity of 37.2 (90% confidence interval=29.98–48.66). Two peaks in prevalence of L. laeviusculus infestations occurred (April and mid-June), and one peak in intensity (June). Juvenile squirrels had higher prevalence and mean intensity when compared to adults. Adult male squirrels had higher mean intensity compared to adult females. Adult lice comprised most of the population infesting emerging adult squirrels in the spring but nymphs predominated for most of the active season of the host. Infestations were highly aggregated with k=0.203 and index of discrepancy D=0.813. The seasonal dynamics of L. laeviusculus appear to be strongly correlated with the annual cycle of the squirrel host.


1974 ◽  
Vol 52 (10) ◽  
pp. 894-902 ◽  
Author(s):  
Hans W. Behrisch

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.


Ethology ◽  
2014 ◽  
Vol 120 (11) ◽  
pp. 1101-1109 ◽  
Author(s):  
Dawson Clary ◽  
Lindsay J. Skyner ◽  
Calen P. Ryan ◽  
Laura E. Gardiner ◽  
W. Gary Anderson ◽  
...  

1976 ◽  
Vol 54 (8) ◽  
pp. 1294-1306 ◽  
Author(s):  
V. Keith Kivett ◽  
Jan O. Murie ◽  
André L. Steiner

Location and hisiology of integumentary glands were investigated in six species of ground squirrels of the genus Spermophilus found in northwestern North America; S. columbianus, S. undulatus, S. richardsonii, S. tridecemlineatus, S. lateralis, and S. franklinii. Among these species, glands in oral, dorsal, and anal regions were structurally similar. Locations of oral and anal glands were identical but location of individual glands in dorsal-gland fields varied considerably. Gland development was greater in S. columbianus and S. undulatus and least in S. franklinii. Active scent marking was most frequent and extensive in S. columbianus and S. undulatus, less frequent in S. lateralis and S. tridecemlineatus, and absent in S. franklinii. In most instances, greeting behavior (which is focused on the mouth-corner oral-gland area) and the degree of sociality paralleled levels of scent marking. A hypothetical scheme of development or scent marking in relation to habitat and social organization is presented. This scheme fits, in general, classical interpretations of phylogeny.


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