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.

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.

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.

Phenological development and seasonal distribution of the rutherglen bug, Nnysius vinitor Bergroth (Hemiptera: Lygaeidae), on various hosts in Victoria, south-eastern Australia

1988 ◽  
Vol 78 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Garrick McDonald ◽  
A. Mark Smith
Keyword(s):  
Rapid Development ◽  
Early Spring ◽  
Common Source ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Polygonum Aviculare ◽  
Developmental Thresholds ◽  
Eastern Australia ◽  
Weed Hosts ◽  
Maximum Temperatures

AbstractPopulations of Nysius vinitor Bergroth were studied from 1979 to 1982 in two weed hosts, Arctotheca calendula and Polygonum aviculare, and eight irrigated sunflower crops in a summer cropping area of northern Victoria, Australia. The spring generation began with the adults colonizing flowering A.calendula plants in September and concluded with the rapid development of late stage nymphs and an exodus of adults from these plants from mid-November to December. Gradual invasion of sunflowers occurred mostly in late December and reached a peak at flowering, after which nymphs appeared. P. aviculare attracted adults from February and hosted a number of overlapping generations until winter. The weed sustained diminishing numbers of adults through the winter, except in 1982, when a further generation produced an early spring peak. Immigrant populations were regarded as a common source of adults for initiating the spring and summer generations. The rate of development of N. vinitor in spring was more rapid than that predicted by phenological simulation based on ambient temperatures and laboratory-derived day-degree estimates. This was attributed to increased body temperatures through absorption of solar radiation, and the simulation model was adjusted by increasing daily minimum and maximum temperatures by 1·3 and 5·5°C for young and older instars, respectively. This suggested that older nymphs have lower developmental thresholds or are better able to optimize body temperatures.

Predation on fish and intersite variation in the diet of common garter snakes, Thamnophis sirtalis, on Vancouver Island

1991 ◽  
Vol 69 (4) ◽  
pp. 988-994 ◽  
Author(s):  
Patrick T. Gregory ◽  
Kari J. Nelson
Keyword(s):  
Temporal Variation ◽  
Body Mass ◽  
Vancouver Island ◽  
Garter Snake ◽  
Prey Abundance ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Site Specific ◽  
The Common

Diets of garter snakes (Thamnophis) often vary in space or time in response to variations in prey abundance. We compared the diet of the common garter snake (T. sirtalis) on Vancouver Island at fish-rearing facilities (hatcheries) and at nearby natural sites where fish were present but less abundant. Snakes of all sizes fed on fish at hatcheries, but fish were rarely eaten at natural sites, where amphibians or earthworms were the major prey types. Any particular characterization of the diet of this species therefore must be site specific. Although snakes exhibited intersite variation in diet, there was no evidence of temporal variation in diet at any site. The proportion of snakes with food in their stomachs varied among sites (perhaps indicating differences in frequency of feeding among sites) and was correlated with mean relative body mass of snakes. This suggests that some sites are more productive than others for snakes, but rigorous tests of whether snake populations are food-limited have not been done.

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.

scholarly journals Genetic architecture of a feeding adaptation: garter snake ( Thamnophis ) resistance to tetrodotoxin bearing prey

2010 ◽  
Vol 277 (1698) ◽  
pp. 3317-3325 ◽  
Author(s):  
Chris R. Feldman ◽  
Edmund D. Brodie ◽  
Edmund D. Brodie ◽  
Michael E. Pfrender
Keyword(s):  
Genetic Architecture ◽  
Genetic Basis ◽  
Allelic Variation ◽  
Natural Populations ◽  
Major Effect ◽  
Garter Snake ◽  
Thamnophis Sirtalis ◽  
Ecological Context ◽  
Garter Snakes ◽  
Genetic Level

Detailing the genetic basis of adaptive variation in natural populations is a first step towards understanding the process of adaptive evolution, yet few ecologically relevant traits have been characterized at the genetic level in wild populations. Traits that mediate coevolutionary interactions between species are ideal for studying adaptation because of the intensity of selection and the well-characterized ecological context. We have previously described the ecological context, evolutionary history and partial genetic basis of tetrodotoxin (TTX) resistance in garter snakes ( Thamnophis ). Derived mutations in a voltage-gated sodium channel gene (Na v 1.4) in three garter snake species are associated with resistance to TTX, the lethal neurotoxin found in their newt prey ( Taricha ). Here we evaluate the contribution of Na v 1.4 alleles to TTX resistance in two of those species from central coastal California. We measured the phenotypes (TTX resistance) and genotypes (Na v 1.4 and microsatellites) in a local sample of Thamnophis atratus and Thamnophis sirtalis . Allelic variation in Na v 1.4 explains 23 per cent of the variation in TTX resistance in T. atratus while variation in a haphazard sample of the genome (neutral microsatellite markers) shows no association with the phenotype. Similarly, allelic variation in Na v 1.4 correlates almost perfectly with TTX resistance in T. sirtalis , but neutral variation does not. These strong correlations suggest that Na v 1.4 is a major effect locus. The simple genetic architecture of TTX resistance in garter snakes may significantly impact the dynamics of phenotypic coevolution. Fixation of a few alleles of major effect in some garter snake populations may have led to the evolution of extreme phenotypes and an ‘escape’ from the arms race with newts.

Control of length of the courtship season in the red-sided garter snake, Thamnophis sirtalis parietalis: the role of temperature

1989 ◽  
Vol 67 (4) ◽  
pp. 987-993 ◽  
Author(s):  
Randolph W. Krohmer ◽  
David Crews
Keyword(s):  
Courtship Behavior ◽  
Temperature Fluctuations ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Ambient Temperatures ◽  
Thamnophis Sirtalis Parietalis ◽  
Laboratory Populations ◽  
Influence Of Temperature On ◽  
The Central Nervous System

The influence of temperature on the length and intensity of the courtship season was examined in both field and laboratory populations of red-sided garter snakes (Thamnophis sirtalis parietalis) over a 2-year period. Snakes were exposed to fluctuations in temperature following emergence from hibernation and activation of courtship behavior. In the field, males were exposed to four temperature regimens: extended hibernation (0L:24D, 4 ± 1.5 °C), cool (14L:10D, 12 ± 2.3° C), warm (14L:10D, 28 °C:ambient), or control (ambient temperatures and light). Control animals exhibited courtship behavior fluctuating in intensity with daily ambient temperatures. Animals exhibited high intensity courtship behavior when exposed to warm conditions following emergence from either natural hibernation or a secondary period of laboratory hibernation. Animals placed in the cool regimen were active but exhibited very little courtship behavior. Animals maintained under the cool regimen for 14 days did not initiate courtship behavior when placed in the warm regimen. Studies conducted in the laboratory support the field results. However, whereas animals maintained under the cool regimen for 14 days and then placed in the warm regimen exhibited dramatically reduced courtship behavior, animals placed in the warm regimen after 21 days under the cool regimen initiated courtship of normal intensity and duration. Following the end of all courtship behavior, males exposed to conditions of hibernation for a brief period reinitiated courtship behavior. These data suggest that the areas of the central nervous system critical for the perception of temperature fluctuations and initiation of courtship behavior remained sensitive in late spring. Following the end of the courtship season, females exposed to a brief period of hibernation also reinstated courtship behavior in noncourting males. These data suggest that the length of the courtship season ultimately may be controlled by the presence of attractive females.

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.

scholarly journals Evolutionary GEM: The Evolutionary Arms Race of Garter Snakes and Newts

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Richard Zhang ◽  
Patricia M. Gray
Keyword(s):  
Evolutionary Biology ◽  
Arms Race ◽  
Garter Snake ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Taricha Granulosa ◽  
Arms Races ◽  
Predator Prey ◽  
Species Pairs ◽  
The Common

In evolutionary biology, predator-prey species pairs can be observed participating in evolutionary arms races between adaptations and counter-adaptations. For example, as a prey becomes more adept at avoiding capture, its predator becomes a more adept hunter. The rough-skinned newt (Taricha granulosa) produces a toxin that protects it from virtually all predators, except one. That one predator is the common garter snake (Thamnophis sirtalis), which has evolved resistance to this toxin. This predator-prey pair is seemingly engaged in a perpetual battle for higher toxicity and better resistance. While both adaptations come with costs, the coexistence of newt and garter snake imposes reciprocal selective pressure that drives this arms race.

Effect of fall mating on ovarian development in the red-sided garter snake

1989 ◽  
Vol 257 (6) ◽  
pp. R1548-R1550 ◽  
Author(s):  
M. T. Mendonca ◽  
D. Crews
Keyword(s):  
Ovarian Development ◽  
Garter Snake ◽  
Thamnophis Sirtalis ◽  
Ovarian Maturation ◽  
Garter Snakes ◽  
Thamnophis Sirtalis Parietalis ◽  
Long Term Storage ◽  
Term Storage

Although spring mating is an important factor in initiating vitellogenesis in female red-sided garter snakes (Thamnophis sirtalis parietalis), some females can become vitellogenic without having mated in the spring. Two hypotheses have been proposed to explain this phenomenon: 1) long-term storage of copulatory stimuli from mating the previous fall, or 2) additional cue(s) overcoming the lack of mating to stimulate vitellogenesis. Through oviductal biopsy, the presence of sperm in females returning to the hibernaculum in the fall was assessed. Laparotomies performed just before and 6 wk after hibernation indicated that although fall mating may stimulate slight ovarian development in the fall, there appears to be no effect of fall mating on spring ovarian recrudescence. Spring mating seems to be the most important factor in determining ovarian maturation. Therefore, it appears that there is no long-term storage of copulatory cues and that other as yet unknown cues are responsible for initiating vitellogenesis in spring unmated females.

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