Effects of humidity, temperature, and submergence behavior on survivorship and energy use in hibernating garter snakes, Thamnophis sirtalis

1989 ◽  
Vol 67 (10) ◽  
pp. 2486-2492 ◽  
Author(s):  
Jon P. Costanzo
Keyword(s):  
Mass Loss ◽  
Energy Use ◽  
Fat Body ◽  
Early Spring ◽  
Survival Duration ◽  
Thamnophis Sirtalis ◽  
Winter Mortality ◽  
Garter Snakes ◽  
Significant Survival ◽  
Additional Group

Desiccation is likely an important factor influencing winter mortality rates of terrestrially hibernating reptiles; however, this notion has not been rigorously tested. Groups of eastern garter snakes (Thamnophis sirtalis sirtalis) were matched for size and subsequently exposed to simulated hibernative conditions (5 or 12 °C, under different humidity regimes) during winter, for 165 days or until all group members expired. As garter snakes in some dens submerge during natural hibernation, an additional group was maintained in water at 5 °C. Snakes kept in air dehydrated and died (body water contents at death ranged from 62.1 to 67.8% of lean fresh mass), whereas snakes kept in water remained hydrated (median, 75.2%) and survived. Survival duration of air hibernators was inversely related to rate of mass loss, which in turn was strongly influenced by ambient humidity and temperature. Dehydration accounted for most of the mass lost in all air hibernators; however, owing to higher rates of nutrient consumption, mass loss was significantly greater in snakes kept at 12 °C (36%) than in snakes kept at 5 °C (29%). Changes in fat body and liver masses showed that snakes kept in air at 12 °C used the most energy whereas those kept in water at 5 °C used the least. Submerged hibernation behavior has significant survival value because under these conditions snakes remain hydrated during winter. Also, because submerged snakes conserve more stored energy during winter, their reproductive success may be enhanced when mating activities resume in early spring.

Female mimicry in garter snakes: behavioural tactics of "she-males" and the males that court them

2000 ◽  
Vol 78 (8) ◽  
pp. 1391-1396 ◽  
Author(s):  
Richard Shine ◽  
David O'Connor ◽  
Robert T Mason
Keyword(s):  
Time Of Day ◽  
Early Spring ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Thermal Threshold ◽  
Male Attractiveness ◽  
Female Mimicry ◽  
Early Afternoon ◽  
Antipredator Responses ◽  
Locomotor Capacity

Red-sided garter snakes (Thamnophis sirtalis parietalis) in central Manitoba court and mate in early spring soon after emerging from communal overwintering dens. Some males ("she-males") produce female-like skin pheromones, and hence attract courtship from other males. Studies at a den near Inwood, Manitoba, support and extend results from work at other dens. She-males were males that had recently emerged from hibernation and had not yet regained full locomotor capacity or muscle strength. She-males resembled "he-males" rather than females in their antipredator responses, including the thermal threshold at which they fled from a simulated predator (a plastic crow) rather than remaining stationary and displaying. Males courting she-males were cooler than those courting females; nonetheless they were more likely to flee when we approached them. Compared with courting groups focussed on females, groups around she-males were smaller, consisted predominantly of smaller he-males, and were found over a more restricted time of day (early afternoon). Arena trials confirmed that she-males are disproportionately courted by small rather than large he-males, and clarified other aspects of she-male attractiveness and behaviour. She-males attracted more intense courtship when large females were absent. She-males courted less vigorously when large he-males were present, especially when they were vigorously courted themselves. Overall, our data reveal hitherto-unsuspected complexity in the behavioural tactics of reproducing garter snakes.

Minimal overwintering temperatures of red-sided garter snakes (Thamnophis sirtalis parietalis): a possible cue for emergence?

2006 ◽  
Vol 84 (5) ◽  
pp. 771-777 ◽  
Author(s):  
Deborah I. Lutterschmidt ◽  
Michael P. LeMaster ◽  
Robert T. Mason
Keyword(s):  
Body Temperature ◽  
Early Spring ◽  
Ground Temperature ◽  
Thamnophis Sirtalis ◽  
Winter Dormancy ◽  
Garter Snakes ◽  
Body Temperatures ◽  
Thamnophis Sirtalis Parietalis ◽  
Spring Emergence ◽  
Insight Into

Red-sided garter snakes ( Thamnophis sirtalis parietalis (Say in James, 1823)) in Manitoba, Canada, undergo 8 months of continuous winter dormancy prior to spring emergence. As in other ectothermic species, increases in ground temperature may be the cue for emergence from winter dormancy in these populations. To test this hypothesis, we measured body temperatures during winter dormancy by surgically implanting small temperature loggers into 32 female red-sided garter snakes before they entered their native hibernaculum. The following spring, we recaptured seven of the snakes implanted with temperature loggers. Body temperature declined gradually from mid-September (14.7 ± 0.24 °C, mean  ± SE) to early April (1.1 ± 0.16 °C, mean ± SE) during winter dormancy, reaching minimal values approximately 1 month prior to spring emergence. Body temperatures of emerging snakes ranged from 0.5 °C during early spring to 6.3 °C during late spring (3.4 ± 0.84 °C, mean ± SE). These results do not support the hypothesis that an increase in ground temperature (and hence body temperature) is necessary for emergence from winter dormancy. We suggest that critically low temperatures (i.e., 0.5–1 °C) are a Zeitgeber entraining an endogenous circannual cycle that regulates snake emergence. These results offer new insight into the mechanisms regulating seasonal emergence from winter dormancy.

Body temperatures and movements of hibernating snakes (Crotalus and Thamnophis) and thermal gradients of natural hibernacula

1989 ◽  
Vol 67 (1) ◽  
pp. 108-114 ◽  
Author(s):  
J. Malcolm Macartney ◽  
Karl W. Larsen ◽  
Patrick T. Gregory
Keyword(s):  
Thermal Gradient ◽  
Reference Site ◽  
Early Spring ◽  
Garter Snake ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Crotalus Viridis ◽  
Northern Alberta

Although temperate zone snakes spend a large part of each year in hibernation, we know relatively little about their behavior during this part of the annual cycle. We used radiotelemetry to monitor temperatures and movements of hibernating rattlesnakes (Crotalus viridis) in southern British Columbia and garter snakes (Thamnophis sirtalis) in northern Alberta, and measured thermal profiles inside their hibernacula. A reference site near the garter snake hibernaculum, superficially resembling a winter den but not used by snakes, also was monitored. A thermal gradient (temperature increasing with depth) formed during the winter in the rattlesnake den, but only minimally so in the garter snake den. Differences in thermal profiles were attributed to differences in subsurface geomorphology. The reference site exhibited much greater temperature fluctuation than the den itself, with lethal temperatures prevailing throughout the winter. Therefore, suitable hibernation sites may be limited in some areas despite a superficial appearance of abundance. As ambient temperatures declined during early winter, snakes made lateral movements inside their hibernacula, and exhibited changes in body temperature which we interpreted as movements to warmer (deeper) microsites. Body temperatures recorded during winter ranged between 2 and 7 °C. In early spring the thermal gradient collapsed and the rattlesnake den gradually underwent a uniform increase in temperature. A similar increase in subterranean temperatures occurred in the garter snake den. Temperature change was perhaps a stimulus for emergence in rattlesnakes, but possibly not in garter snakes. The hypothesis that hibernating snakes orient along a seasonally reversing thermal gradient is not unambiguously supported.

Species-isolating mechanisms in a mating system with male mate choice (garter snakes, Thamnophis spp.)

2004 ◽  
Vol 82 (7) ◽  
pp. 1091-1098 ◽  
Author(s):  
Richard Shine ◽  
Benjamin Phillips ◽  
Heather Waye ◽  
Michael Lemaster ◽  
Robert T Mason
Keyword(s):  
Warm Season ◽  
Mate Recognition ◽  
Early Spring ◽  
Morphological Data ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Temporal Separation ◽  
Ambient Temperatures ◽  
Male Mate ◽  
Species Specific

Reproductive isolation between sympatric taxa can be maintained by specific mate-recognition behaviours or by ecological divergence that reduces interspecific contact during reproduction. Common garter snakes, Thamnophis sirtalis (L., 1758), and plains garter snakes, Thamnophis radix (Baird and Girard, 1853), are sympatric over large areas, but morphological data suggest that the prezygotic isolation between these two species partially breaks down in a severely cold part of their joint range in Manitoba. Courtship trials show that male T. radix court intensely over a narrower range of (higher) ambient temperatures than do male T. sirtalis. Males selectively court females of their own species, but male T. radix are less choosy than male T. sirtalis. Hexane extracts of female skin lipids also elicited species-specific courtship. Although this male preference for species-specific pheromones contributes to species isolation, it is not strong enough to completely separate the two taxa. The absence of hybridization over most of the sympatric range may depend on the timing of mating (early spring, near the hibernation den). Differences between the species in hibernation-site selection and the timing of spring emergence break down in central Manitoba because severely cold winter temperatures force both species together into the few available hibernation (and thus, mating) sites, and the short warm season reduces temporal separation in emergence (and thus, mating) seasons.

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.

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