How Do Red Squirrels, Tamiasciurus hudsonicus, and Eastern Chipmunks, Tamias striatus, Coexist?

Oikos ◽  
1998 ◽  
Vol 83 (1) ◽  
pp. 139 ◽  
Author(s):  
Barbara Guerra ◽  
William L. Vickery
Keyword(s):  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Tamias Striatus ◽  
Eastern Chipmunks

scholarly journals Consumption of Truffles and other Fungi by the American Red Squirrel (Tamiasciurus hudsonicus) and the Eastern Chipmunk (Tamias striatus) (Sciuridae) in Northwestern Ontario

2013 ◽  
Vol 127 (1) ◽  
pp. 57 ◽  
Author(s):  
Jocelin N. Teron ◽  
Leonard J. Hutchison
Keyword(s):  
Tamiasciurus Hudsonicus ◽  
Red Squirrel ◽  
Red Squirrels ◽  
Tamias Striatus ◽  
Eastern Chipmunk ◽  
Northwestern Ontario ◽  
Thunder Bay ◽  
Faecal Samples ◽  
The Family ◽  
Fungal Tissue

Faecal matter collected from the American Red Squirrel (Tamiasciurus hudsonicus) and the Eastern Chipmunk (Tamias striatus) on the campus of Lakehead University in Thunder Bay, Ontario, was examined for the presence of consumed fungal tissue. A total of 14 faecal samples were collected from live-trapped animals over six trapping periods (19 June to 25 September 2010). Eight samples contained intact remains of spores representative of hypogeous truffle fungi found in the genera Elaphomyces, Gautieria, Hymenogaster, Hysterangium, and Leucangium, as well as spores of epigeous mushrooms found in the orders Boletales and Pezizales and possibly in the family Tricholomataceae of the Agaricales. The results of this brief survey suggest not only the importance of mycophagy in the diet of American Red Squirrels and Eastern Chipmunks in the boreal mixed wood forests of northwestern Ontario but also the important role played by sciurids in vectoring spores of truffle fungi in this region.

scholarly journals High Prevalence of Borrelia mayonii (Spirochaetales: Spirochaetaceae) in Field-Caught Tamias striatus (Rodentia: Sciuridae) From Northern Wisconsin

2021 ◽  
Author(s):  
Patricia N Siy ◽  
Ryan T Larson ◽  
Tela E Zembsch ◽  
Xia Lee ◽  
Susan M Paskewitz
Keyword(s):  
Ixodes Scapularis ◽  
Tamiasciurus Hudsonicus ◽  
Infection Prevalence ◽  
Glaucomys Volans ◽  
Blarina Brevicauda ◽  
Tamias Striatus ◽  
Napaeozapus Insignis ◽  
High Prevalence ◽  
Sorex Cinereus ◽  
Eastern Chipmunks

Abstract Borrelia mayonii is a recently discovered bacterial spirochete that causes Lyme disease and is transmitted by the blacklegged tick, Ixodes scapularis Say (Acari: Ixodidae). To date, B. mayonii has been isolated from two vertebrate host species in Minnesota: field-caught white-footed mice (Peromyscus leucopus Rafinesque; Rodentia: Cricetidae) and American red squirrel (Tamiasciurus hudsonicus Erxleben). Here, we describe the first detection of B. mayonii in field-caught eastern chipmunks (Tamias striatus L. (Rodentia: Cricetidae)) from northern Wisconsin. During our study, we captured 530 unique small mammals and found an infection prevalence of 23.50% in field-caught eastern chipmunks (4/17) and 1.19% in Peromyscus spp. (5/420). Mean larval and nymphal burdens were determined for captured Blarina brevicauda (0, 0), Glaucomys volans (0.29, 0.14), Myodes gapperi (0.27, 0), Napaeozapus insignis (0, 0.25), Peromyscus spp. (1.88, 0.11), T. striatus (1.06, 0.65), and Sorex cinereus (0.09, 0). The high B. mayonii infection prevalence in eastern chipmunks suggests that the species may be an important reservoir for B. mayonii in the Upper Midwest.

scholarly journals Potential of Small Culverts as Wildlife Passages on Forest Roads

2021 ◽  
Vol 13 (13) ◽  
pp. 7224
Author(s):  
Hsiang-Ling Chen ◽  
Erin E. Posthumus ◽  
John L. Koprowski
Keyword(s):  
Animal Movement ◽  
Small Dimension ◽  
Lynx Rufus ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Forest Roads ◽  
Alternative Pathways ◽  
Slow Moving ◽  
Trail Cameras ◽  
Spermophilus Variegatus

Roads and traffic can cause animal mortality. Specifically, roads serve as barriers by impeding animal movement, resulting in demographic and genetic consequences. Drainage structures, such as culverts, can provide linkages between habitat patches. However, the potential of small culverts with diameters of <60 cm (e.g., wildlife passages that facilitate movement on forest roads) are relatively unknown. In this study, we used trail cameras to monitor the use of 14 small culverts, by mammals, along forest roads on Mt. Graham, home of the critically endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis), in southeastern Arizona, USA. From 2011 to 2013, we only recorded 20 completed road crossings through culverts. More than half of culvert uses were by striped skunks (Mephitis mephitis), followed by the rock squirrel (Spermophilus variegatus) and the bobcat (Lynx rufus). The Mt. Graham red squirrel was the only species that was common along the roads, but never crossed the roads. Culverts with higher usages were characterized by shorter culvert lengths and absence of accumulated soil inside the culverts. Our study shows that small-dimension drainage systems may provide alternative pathways for wildlife crossing roads, especially for slow moving and ground dwelling species. However, the potential of small culverts assisting wildlife crossings can only be maximized when culverts are accessible year-round.

Hibernation of eastern chipmunks (Tamias striatus) maintained under controlled conditions

1972 ◽  
Vol 50 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Grace Workman Scott ◽  
Kenneth C. Fisher
Keyword(s):  
Temperature Sensors ◽  
Endogenous Rhythm ◽  
Bottom Temperature ◽  
Tamias Striatus ◽  
Controlled Conditions ◽  
Eastern Chipmunks ◽  
First Time ◽  
Periodic Arousals

The hibernation pattern of captive eastern chipmunks maintained under controlled conditions of light and temperature was examined. It was consistent with the view that hibernation results from an endogenous rhythm with a periodicity of about a year, probably temperature independent.Continuous recording from nest bottom temperature sensors was tested for the first time with this species and found to be more accurate than the sawdust technique for detecting arousals. It also provided useful information about trends in body temperature.The hypothesis that a shift in the temperature at which heat-producing responses are mobilized occurs during hibernation and that it is responsible for the pattern of periodic arousals, is discussed in relation to the observations made.

Jack pine cone quality and cache sizes of red squirrels in southern New Brunswick, Canada

1997 ◽  
Vol 75 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Michael A. Setterington ◽  
Daniel M. Keppie
Keyword(s):  
New Brunswick ◽  
Pinus Banksiana ◽  
Seed Mass ◽  
Dry Mass ◽  
Jack Pine ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Length Width ◽  
Total Seed ◽  
Number Of Seeds

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.

STUDIES ON THE BIOLOGY OF TAENIA CRASSICEPS (ZEDER, 1800) RUDOLPHI, 1810 (CESTODA)

1962 ◽  
Vol 40 (6) ◽  
pp. 969-990 ◽  
Author(s):  
Reino S. Freeman
Keyword(s):  
Initial Rate ◽  
Subsequent Development ◽  
Microtus Pennsylvanicus ◽  
Tamiasciurus Hudsonicus ◽  
Sciurus Carolinensis ◽  
New Host ◽  
Tamias Striatus ◽  
Taenia Crassiceps ◽  
Marmota Monax ◽  
New Host Records

Taenia crassiceps was common in Vulpes fulva examined from southern Ontario. Metacestodes occurred naturally in Microtus pennsylvanicus, Marmota monax, Tamias striatus, and Ondatra zibethicus, and Peromyscus maniculatus, Tamiasciurus hudsonicus, and Sciurus carolinensis were infected experimentally; all rodents are new host records. Cysticerci developed into adults in dogs or foxes within 5 to 6 weeks; five coyote pups resisted infection. Development of the metacestode was followed mainly in white mice. Infections were most common subcutaneously, but also occurred in both body cavities. Mice approximately 4 weeks of age were most susceptible. Asexual reproduction occurred by exogenous, and rarely endogenous, budding from the abscolex pole beginning approximately 3 weeks after infection. Metacestodes in various stages of development were injected into mice subcutaneously, intrapleurally, but mainly intraperitoneally. Subsequent development and reproduction were similar to that following infection with eggs. Apparently all metacestodes are capable of budding. The initial rate of reproduction was higher subcutaneously and intrapleurally than intraperitoneally, but within approximately 100 days the rate became higher and continued higher intraperitoneally than elsewhere. Reproduction never reached a logarithmic rate. Metacestodes inoculated serially up to 21 times at 50-day intervals increased greatly in size and continued budding. Four other series were maintained by serial subinoculation at 50-day intervals through 23 generations without a significant change in the rate of reproduction.

SEASONAL DAMAGE BY INSECTS AND SQUIRRELS TO FEMALE REPRODUCTIVE STRUCTURES OF BLACK SPRUCE, PICEA MARIANA (MILL.) B.S.P.

1988 ◽  
Vol 120 (12) ◽  
pp. 1113-1121 ◽  
Author(s):  
Y.H. Prévost ◽  
J.E. Laing ◽  
V.F. Haavisto
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrel ◽  
Red Squirrels ◽  
Reproductive Structures ◽  
Cone Axis ◽  
Viable Seeds ◽  
Cone Growth

AbstractThe seasonal damage to female reproductive structures (buds, flowers, and cones) of black spruce, Picea mariana (Mill.) B.S.P., was assessed during 1983 and 1984. Nineteen insects (five Orders) and the red squirrel, Tamiasciurus hudsonicus (Erxleben), were found feeding on these reproductive structures. Collectively, these organisms damaged 88.9 and 53.5% of the cones in 1983 and 1984, respectively. In the 2 years, Lepidoptera damaged 61.8% of the cones in 1983 and 44.4% of the cones in 1984. The spruce budworm, Choristoneura fumiferana (Clem.), and the spruce coneworm, Dioryctria reniculelloides Mut. and Mun., were the most important pests. Cones damaged by Lepidoptera could be classed into three categories: (a) severe, yielding no seeds; (b) moderate, yielding 22.3 seeds per cone; and (c) light, yielding 37.5 seeds per cone. Undamaged cones yielded on average 39.9 seeds per cone. Red squirrels removed 18.8% of the cones in 1983 and none in 1984. The spruce cone axis midge, Dasineura rachiphaga Tripp, and the spruce cone maggot, Lasiomma anthracinum (Czerny), caused minor damage in both years. Feeding by spruce cone axis midge did not reduce cone growth significantly or the number of viable seeds per cone, but feeding by the spruce cone maggot did. During both years new damage by insects to the female reproductive structures of the experimental trees was not observed after mid-July. In 1983 damage by red squirrels occurred from early to late September. In 1984 damage to cones on trees treated with dimethoate was 15.6% compared with 53.5% for untreated trees, without an increase in the number of aborted cones.

scholarly journals Is biasing offspring sex ratio adaptive? A test of Fisher's principle across multiple generations of a wild mammal in a fluctuating environment

2018 ◽  
Vol 285 (1891) ◽  
pp. 20181251 ◽  
Author(s):  
Andrea E. Wishart ◽  
Cory T. Williams ◽  
Andrew G. McAdam ◽  
Stan Boutin ◽  
Ben Dantzer ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Offspring Sex Ratio ◽  
Offspring Sex ◽  
Adult Sex Ratio ◽  
Secondary Sex Ratio ◽  
North American Red Squirrels ◽  
Negative Frequency Dependent Selection ◽  
Fisher’S Principle

Fisher's principle explains that population sex ratio in sexually reproducing organisms is maintained at 1 : 1 owing to negative frequency-dependent selection, such that individuals of the rare sex realize greater reproductive opportunity than individuals of the more common sex until equilibrium is reached. If biasing offspring sex ratio towards the rare sex is adaptive, individuals that do so should have more grandoffspring. In a wild population of North American red squirrels ( Tamiasciurus hudsonicus ) that experiences fluctuations in resource abundance and population density, we show that overall across 26 years, the secondary sex ratio was 1 : 1; however, stretches of years during which adult sex ratio was biased did not yield offspring sex ratios biased towards the rare sex. Females that had litters biased towards the rare sex did not have more grandoffspring. Critically, the adult sex ratio was not temporally autocorrelated across years, thus the population sex ratio experienced by parents was independent of the population sex ratio experienced by their offspring at their primiparity. Expected fitness benefits of biasing offspring sex ratio may be masked or negated by fluctuating environments across years, which limit the predictive value of the current sex ratio.

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