Relationships between Annual Cycles of Testosterone, Corticosterone, and Body Condition in Male Red‐Spotted Garter Snakes, Thamnophis sirtalis concinnus

2000 ◽  
Vol 73 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Ignacio T. Moore ◽  
Jennifer P. Lerner ◽  
Darren T. Lerner ◽  
Robert T. Mason
Keyword(s):  
Body Condition ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Annual Cycles

scholarly journals Age-related sex differences in body condition and telomere dynamics of red-sided garter snakes

2017 ◽  
Vol 284 (1852) ◽  
pp. 20162146 ◽  
Author(s):  
Nicky Rollings ◽  
Emily J. Uhrig ◽  
Randolph W. Krohmer ◽  
Heather L. Waye ◽  
Robert T. Mason ◽  
...  
Keyword(s):  
Telomere Length ◽  
Body Condition ◽  
Life Histories ◽  
Life History Strategies ◽  
Breeding Period ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Cross Sectional ◽  
Age Related ◽  
Males And Females

Life-history strategies vary dramatically between the sexes, which may drive divergence in sex-specific senescence and mortality rates. Telomeres are tandem nucleotide repeats that protect the ends of chromosomes from erosion during cell division. Telomeres have been implicated in senescence and mortality because they tend to shorten with stress, growth and age. We investigated age-specific telomere length in female and male red-sided garter snakes, Thamnophis sirtalis parietalis . We hypothesized that age-specific telomere length would differ between males and females given their divergent reproductive strategies. Male garter snakes emerge from hibernation with high levels of corticosterone, which facilitates energy mobilization to fuel mate-searching, courtship and mating behaviours during a two to four week aphagous breeding period at the den site. Conversely, females remain at the dens for only about 4 days and seem to invest more energy in growth and cellular maintenance, as they usually reproduce biennially. As male investment in reproduction involves a yearly bout of physiologically stressful activities, while females prioritize self-maintenance, we predicted male snakes would experience more age-specific telomere loss than females. We investigated this prediction using skeletochronology to determine the ages of individuals and qPCR to determine telomere length in a cross-sectional study. For both sexes, telomere length was positively related to body condition. Telomere length decreased with age in male garter snakes, but remained stable in female snakes. There was no correlation between telomere length and growth in either sex, suggesting that our results are a consequence of divergent selection on life histories of males and females. Different selection on the sexes may be the physiological consequence of the sexual dimorphism and mating system dynamics displayed by this species.

Eastern Garter Snakes (Thamnophis sirtalis) with proportionally larger heads are in better condition

2011 ◽  
Vol 32 (3) ◽  
pp. 424-427 ◽  
Author(s):  
Karen Elgee ◽  
Gabriel Blouin-Demers
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Sexual Size Dimorphism ◽  
Head Size ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Size Dimorphism ◽  
Trophic Morphology ◽  
Large Head ◽  
The Relationship

AbstractWe investigated sexual size dimorphism and trophic morphology dimorphism in Eastern Garter Snakes (Thamnophis sirtalis) to test predictions derived from the reproductive role hypothesis. Our first objective was to examine whether structures involved in feeding (head and jaws) are more divergent than body size. Female T. sirtalis were larger than males and had proportionally larger heads. Our second objective was to look for an advantage of large head size by examining the relationship between body condition and head size. Body condition was positively correlated with relative head size in T. sirtalis for both sexes, in agreement with the reproductive role hypothesis.

scholarly journals Familiarity with a female does not affect a male’s courtship intensity in garter snakes Thamnophis sirtalis parietalis

2012 ◽  
Vol 58 (6) ◽  
pp. 805-811 ◽  
Author(s):  
Richard Shine ◽  
Jonathan K. Webb ◽  
Amanda Lane ◽  
Robert T. Mason
Keyword(s):  
Mate Choice ◽  
Current Theory ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Lizard Species ◽  
Female Body Size ◽  
Courtship Intensity ◽  
Wide Range ◽  
Size Condition ◽  
Experimental Trials

Abstract In many animal species, males direct more intense courtship towards females they have not previously encountered, than towards females with which they have previously mated. To test the factors responsible for this “Coolidge Effect”, we need studies on a wide range of taxa – including those with mating systems in which we would not expect (based on current theory) that such an effect would be evident. The Coolidge Effect has been documented in several lizard species, but has not been looked for (and would not be expected) in snakes. We conducted experimental trials with red-sided garter snakes Thamnophis sirtalis pa-rietalis at a communal den in Manitoba, to see whether previous exposure to a female (either courting, or courting plus mating) modified male mate choice or courtship intensity. In keeping with prediction from theory (but contrary to an early anecdotal report), male garter snakes did not modify their courtship behaviour based upon their familiarity (or lack thereof) with a specific female. At least in large courting aggregations, male snakes may maximize their fitness by basing mate-choice upon immediate attributes of the female (body size, condition, mated status) and the intensity of competition (numbers and sizes of rival males) rather than information derived from previous sexual encounters.

Recovery of Garter Snakes (Thamnophis sirtalis) from the Effects of Tetrodotoxin

2002 ◽  
Vol 36 (1) ◽  
pp. 95
Author(s):  
Edmund D. Brodie III ◽  
Edmund D. Brodie Jr. ◽  
Jeffrey E. Motychak
Keyword(s):  
Thamnophis Sirtalis ◽  
Garter Snakes

Structural flexibility of the small intestine and liver of garter snakes in response to feeding and fasting

2002 ◽  
Vol 205 (10) ◽  
pp. 1377-1388 ◽  
Author(s):  
J. Matthias Starck ◽  
Kathleen Beese
Keyword(s):  
Cell Proliferation ◽  
Small Intestine ◽  
Organ Size ◽  
Transitional Epithelium ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Liver Size ◽  
Mucosal Epithelium ◽  
Functional Features ◽  
Python Molurus Bivittatus

SUMMARYGarter snakes Thamnophis sirtalis parietalis feed frequently but also tolerate extended periods of fasting when food is unavailable. We studied the dynamics, reversibility and repeatability of size changes of the small intestine and liver using ultrasonography. We employed light and transmission electron microscopy and flow cytometry to study the tissue mechanism that drives this flexibility. We compared garter snakes that fed every other day,snakes that fed once a week and fasting snakes. In all feeding trials, the size of the small intestine and the liver increased rapidly after feeding. Constantly feeding snakes maintained an elevated level of organ size, while snakes that were fed only once a week showed a marked up- and downregulation of organ size. Histology revealed the mucosal epithelium to be a transitional epithelium that can change cell configuration considerably to accommodate organ size changes. Upregulation of small intestine and liver size was always associated with the incorporation of lipid droplets into enterocytes and hepatocytes. Cell proliferation was not involved in upregulation of organ size. In contrast, cell proliferation increased during downregulation of organ size, indicating that cells worn out during digestion were replaced. The dynamics of flexibility and the functional features of the tissue were the same as described for the Burmese python Python molurus bivittatus. We suggest that garter snakes employ the same energetically cheap mechanism of organ size regulation as pythons, which allows for rapid, repeated and reversible size changes with no cell proliferation involved. Comparative evidence suggests that the transitional mucosal epithelium is an ancestral character of snakes and that feeding ecology is not directly related to the cytological features of the mucosal epithelium.

Effects of intracoelomic alfaxalone–dexmedetomidine on righting reflex in common garter snakes (Thamnophis sirtalis): preliminary data

2020 ◽  
Vol 47 (6) ◽  
pp. 793-796
Author(s):  
Kelly Chen ◽  
Stephanie Keating ◽  
Danielle Strahl-Heldreth ◽  
Stuart Clark-Price
Keyword(s):  
Preliminary Data ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Righting Reflex
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