Shyness-Boldness, but not Exploration, Predicts Glucocorticoid Stress Response in Richardson's Ground Squirrels (Urocitellus richardsonii)

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


2021 ◽  
Author(s):  
Caila E. Kucheravy ◽  
Jane M. Waterman ◽  
Elaine A.C. Anjos ◽  
James F. Hare ◽  
Chris Enright ◽  
...  

Abstract Hibernating ground squirrels rely on a short active period for breeding and mass accrual, and are thus vulnerable to extreme climate events that affect key periods in their annual cycle. Here, we observed how a heatwave in March 2012 led to a phenological mismatch between sexes in Richardson’s ground squirrels (Urocitellus richardsonii). Females emerged from hibernation and commenced breeding earlier in 2012 relative to average female emergence. Despite external indicators suggesting that males were prepared for breeding, it appeared that not all males were physiologically prepared since 58.6% of males had non-motile sperm when breeding commenced. We found that males with non-motile sperm had smaller accessory glands than males with motile sperm. Body condition, relative testes size, and the relative size of accessory glands were significant predictors of sperm motility. There was no difference in litter size among years, nor a decrease in the number of juveniles emerged in 2012 or female yearlings recruited in 2013. The impact of this heatwave on male ground squirrels emphasizes the importance of assessing the consequences of climate change on breeding success of hibernating species in both sexes, since the different cues for emergence led to a mismatch in timing under this event.


2019 ◽  
Vol 6 (9) ◽  
pp. 190904 ◽  
Author(s):  
Angela R. Freeman ◽  
Thomas J. Wood ◽  
Kevin R. Bairos-Novak ◽  
W. Gary Anderson ◽  
James F. Hare

Within matrilineal societies, the presence of mothers and female kin can greatly enhance survival and reproductive success owing to kin-biased alarm calling, cooperation in territory defence, protection from infanticidal conspecifics, joint care of young and enhanced access to resources. The removal of mothers by predators or disease is expected to increase the stress experienced by offspring via activation of their hypothalamic-pituitary-adrenal axis, increasing circulating glucocorticoids and reducing offspring survival and reproductive success. Yet, few studies have removed mothers in the post-weaning period to examine the assumed physiological and fitness consequences associated with these mortality events. We examined how the loss of a mother affects juvenile Richardson's ground squirrels' ( Urocitellus richardsonii ) faecal glucocorticoid metabolites and their survival. Given that neighbours are often close kin, we further hypothesized that conspecific removal would similarly diminish the fitness of neighbouring individuals. Upon removing the mother, we detected no impact on offspring or neighbouring conspecific faecal glucocorticoid metabolites in the removal year, or on overwinter survival in the following year. Furthermore, no impact on neighbour reproductive success was detected. Given the high predation rates of ground squirrels in wild populations, resilience to a changing social environment would prove adaptive for both surviving kin and non-kin.


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.


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.


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