The following papers and theses have been published on the eastern ribbonsnake in Nova Scotia:
Gilhen, John, Alice Jones, Jeffie McNeil, and Arthur W. Tanner. 2012. A significant range extension for the Eastern Ribbonsnake, Thamnophis sauritus, in Nova Scotia, Canada. Canadian Field-Naturalist 126(3): 231-233.
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Abstract / Description:
In Nova Scotia the threatened Northern Ribbonsnake, Thamnophis sauritus septentrionalis, (the northern subspecies of the Eastern Ribbonsnake, T. sauritus) (Crother 2008) is known from localities in only Queens and Lunenburg counties, where it was first discovered in 1950. Many new localities, mostly in the headwaters of the Mersey River and the Medway River
watersheds have
In Nova Scotia the threatened Northern Ribbonsnake, Thamnophis sauritus septentrionalis, (the northern subspecies of the Eastern Ribbonsnake, T. sauritus) (Crother 2008) is known from localities in only Queens and Lunenburg counties, where it was first discovered in 1950. Many new localities, mostly in the headwaters of the Mersey River and the Medway River
watersheds have been added since 2002, and Seven Mile Lake (in the West La Have River watershed) was added to the distribution in 2005. We add two localities to the distribution of the Northern Ribbonsnake in the previously unreported Petite Rivière watershed, Lunenburg County, Nova Scotia.
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Amiel, J. and R. Wassersug. 2010. Temperature differentials between the bodies and tails of ribbon snakes (Thamnophis sauritus): ecological and physiological implications. Amphibia-Reptilia 31 (2010): 257-263.
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Abstract / Description:
We present evidence that eastern ribbon snakes (Thamnophis sauritus) at low environmental temperatures can maintain significant temperature differentials between their bodies and tails. We used a high resolution infrared camera to record thermal data from ribbon snakes in the spring and summer. An independent two sample t -test confirmed that ribbon snakes at low spring environmental temp
We present evidence that eastern ribbon snakes (Thamnophis sauritus) at low environmental temperatures can maintain significant temperature differentials between their bodies and tails. We used a high resolution infrared camera to record thermal data from ribbon snakes in the spring and summer. An independent two sample t -test confirmed that ribbon snakes at low spring environmental temperatures maintain significantly warmer bodies than tails relative to ribbon snakes at high summer environmental temperatures (t = 5.495,P <0.001). Given our results that ribbon snakes at low environmental temperatures are able to maintain body temperatures higher than tail temperatures, we speculate on possible mechanisms that could account for these temperature differentials and their ecological significance.
Nous cherchons à savoir si les couleuvres minces (Thamnophis sauritus (L., 1766)) utilisent l’élévation du niveau d’eau comme signal pour l’émergence de l’hibernation. Nous examinons aussi les hypothèses selon lesquelles les couleuvres utilisent des gradients thermiques ou des repères endogènes comme signaux d’émergence. Douze hibernacles artificiels ont servi à loger 15 couleuvres minces. Le niveau d’eau et la température y étaient contrôlés. Quatre couleuvres minces sont sorties d’hibernation sans aucune manipulation du niveau d’eau ni de la température. Huit couleuvres ont émergé après que les conditions thermiques de leur hibernacle eurent changé. Parmi celles-ci, une a émergé après que son hibernacle ait été réchauffé plus en surface qu’en profondeur, quatre après que la température de la pièce ait été élevée à 9 °C et trois après que la surface de leur habitacle ait été éclairé par des ampoules lumineuses incandescentes. Trois couleuvres sont mortes durant l’hibernation. Huit couleuvres ont choisi d’hiberner complètement submergées dans l’eau. Bien que l’échantillon soit trop petit pour en tirer des conclusions statistiquement significatives à α = 0,05, nos observations globales laissent croire que les couleuvres minces n’utilisent pas le niveau d’eau comme signal de l’émergence. Même si l’augmentation du niveau de l’eau ne semble pas être un signal pour l’émergence, l’hibernation sous le niveau de la nappe phréatique peut augmenter la survie en diminuant le métabolisme et en éliminant le risque de dessiccation.
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Todd, J. and R. Wassersug. 2010. Caudal pseudoautotomy in the Eastern Ribbon Snake,Thamnophis sauritus. Amphibia-Reptilia 31 (2010): 213-215.
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Abstract / Description:
Frequent tail loss has been reported in a variety of reptiles including sphenodonts, lizards, amphisbaenids, and snakes. We report evidence of non-specialized pseudoautotomy as an antipredator defense in the Eastern Ribbon Snake Thamnophis sauritus. In field studies in Nova Scotia, Canada, T. sauritus were frequently found with partial tails, during three capture attempts T.
Frequent tail loss has been reported in a variety of reptiles including sphenodonts, lizards, amphisbaenids, and snakes. We report evidence of non-specialized pseudoautotomy as an antipredator defense in the Eastern Ribbon Snake Thamnophis sauritus. In field studies in Nova Scotia, Canada, T. sauritus were frequently found with partial tails, during three capture attempts T. sauritus tails became completely or partially detached, and one detached tail twitched repeatedly after separation. The breakage was intervertebral, suggesting pseudoautotomy (i.e., that the snake's tail anatomy was not specialized for easy tail loss). Although tail loss patterns in T. sauritus have been well documented, to our knowledge this is the first time pseudoautotomy has been reported in T. sauritus.
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Imlay, T. 2009. Examining spatial ecology at multiple scales: implications for eastern ribbonsnake (Thamnophis sauritus) recovery in Nova Scotia. MSc thesis. Acadia University. Wolfville, NS.
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Abstract / Description:
The Eastern ribbonsnake (Thamnophis sauritus) is a threatened species in Nova Scotia. Many threats and limiting factors have been identified for the species, however the lack of knowledge surrounding movement patterns and habitat use inhibit recovery decisions. Ribbonsnakes were hand-caught during visual surveys at Grafton and Molega Lakes in 2007. Two methods for tracking ribbonsnakes we
The Eastern ribbonsnake (Thamnophis sauritus) is a threatened species in Nova Scotia. Many threats and limiting factors have been identified for the species, however the lack of knowledge surrounding movement patterns and habitat use inhibit recovery decisions. Ribbonsnakes were hand-caught during visual surveys at Grafton and Molega Lakes in 2007. Two methods for tracking ribbonsnakes were examined. External radio-transmitter attachment was unsuccessful; this was attributed to slender body shape and the habitat used by the species. Fluorescent powder-tracking, using a water-resistant paste of powder and mineral oil, was successful for documenting paths for 1.3 – 16.5 m. Ribbonsnakes were observed in dry areas during late spring and fall and were concentrated along the shoreline of the marshes in summer. Snakes tended to aggregate during ecdysis. Upland observations of ribbonsnakes in early spring and late fall suggest that hibernacula may be located in these areas. Habitat models revealed ribbonsnakes selected habitat based on temperature, substrate and cover (Grafton Lake only) and that habitat selection differed between sites.Individual movements, recapture rates and home ranges suggest that ribbonsnake movements are more extensive than previously thought and that site fidelity between years is high. Fractal analysis of movement paths revealed that ribbonsnakes respond to habitat at least three different scales, 3.5- 9.2, 9.2-11.4 and 15.3- 24.6 cm and that adults appear to respond to habitat at a finer scale than juveniles. Ribbonsnakes tended to display oriented movement, with considerable use of arboreal habitat.
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Saroli, J. 2009. Habitat use and movement of the Eastern ribbonsnake (Thamnophis sauritus) at meso-scales.BScH thesis, Acadia University, Wolfville, NS.
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Abstract / Description:
The Eastern Ribbonsnake (Thamnophis sauritus) is listed as a threatened species in Nova Scotia. The threat of diminishing habitat due to shoreline property development combined with a general dearth of knowledge on the snakes' movements and habitat use complicates conservation and potential recovery planning. Visual surveys were conducted at Molega Lake, an area known to contain a small p
The Eastern Ribbonsnake (Thamnophis sauritus) is listed as a threatened species in Nova Scotia. The threat of diminishing habitat due to shoreline property development combined with a general dearth of knowledge on the snakes' movements and habitat use complicates conservation and potential recovery planning. Visual surveys were conducted at Molega Lake, an area known to contain a small population of Ribbonsnakes. The survey area was expanded in 2008 from previous studies to include four new areas, chosen along the shoreline at varying distances from the original site. The new areas, chosen based on reports of sightings, similarity of habitat, and proximity to the previous study site were surveyed along with the original site. Snakes were hand-captured and identified. Eligible specimens were implanted with a subcutaneous passive integrated transponder as a means of identification. Individual movements were small, with maximum recorded movements shown to be less than that of the smallest distance between survey zones. Home range, calculated from an individual with many recaptures was shown to encompass most of the original survey zone; however, no specimens were observed in more than one area over the four month research season, despite the more populous areas being approximately only 175m apart. Total observations of individual snakes were very low for two of the new areas, and one area showed a marked decrease of observations in the months of July and August. Almost all of the observations occurred within the current critical habitat description, with no sightings in the area specifically chosen for its different habitat type.
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Todd, J., J. Amiel, and R. Wassersug. 2009. Factors influencing the emergence of a northern population of eastern ribbonsakes ( Thamnophis sauritus ) from artificial hibernacula. Canadian Journal of Zoology 87: 1221-1226.
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Abstract / Description:
We investigated whether Eastern Ribbon Snakes (Thamnophis sauritus (L., 1766)) use a rise in water level as a cue for emergence from hibernation. We also examined the hypotheses that snakes use temperature gradients or endogenous signals as emergence cues. Twelve artificial hibernacula were used to house 15 Ribbon Snakes. Water level and temperature were regulated. Four Ribbon Snakes emer
We investigated whether Eastern Ribbon Snakes (Thamnophis sauritus (L., 1766)) use a rise in water level as a cue for emergence from hibernation. We also examined the hypotheses that snakes use temperature gradients or endogenous signals as emergence cues. Twelve artificial hibernacula were used to house 15 Ribbon Snakes. Water level and temperature were regulated. Four Ribbon Snakes emerged from hibernation without any manipulation of water level or temperature. Eight snakes emerged after thermal conditions in their hibernacula changed. Of these, one emerged after the hibernaculum was made warmer on the surface than at depth, four emerged after the room temperature was increased to 9 °C, and three emerged after incandescent lights were shone on the surface of each hibernaculum. Three snakes died during hibernation. Eight snakes chose to hibernate fully submerged in water. Although the sample size is too small to draw conclusions that are statistically significant at α = 0.05, our observations collectively suggest that Ribbon Snakes do not use a rise in water level as a cue to emerge. While water-level rise does not appear to be an emergence cue, hibernation below the water table may lead to increased survivorship by decreased metabolism and elimination of the risk of desiccation.
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McLaughlin, C. 2008. Microsatellite analysis of population structure in the eastern ribbonsnake,Thamnophis sauritus. BScH thesis. Acadia University. Wolfville, NS.
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Abstract / Description:
The Eastern Ribbonsnake, Thamnophis sauritus, exists in Nova Scotia as a disjunct population in the Southwest region of the province. This small population, estimated at 1000-3000 individuals, is particularly vulnerable to change due to its isolation and, therefore, was classified as ‘threatened’ in 2002 by COSEWIC. Because very little is known about the behaviour, ecology, and geneti
The Eastern Ribbonsnake, Thamnophis sauritus, exists in Nova Scotia as a disjunct population in the Southwest region of the province. This small population, estimated at 1000-3000 individuals, is particularly vulnerable to change due to its isolation and, therefore, was classified as ‘threatened’ in 2002 by COSEWIC. Because very little is known about the behaviour, ecology, and genetic structure of this species, there is a rare opportunity to analyse the dynamics of a disjunct, peripheral population. Understanding the genetic structure of this population is fundamental to designing conservation and management plans for the species. Samples were taken from 83 snakes in the form of tail clippings from 4 different areas in the south western portion of Nova Scotia, as well as an outgroup from Nantucket, Massachusetts. One microsattellite loci was amplified and found to exhibit polymorphism with multiple alleles. Results show that there is evidence for the presence of low to moderate restriction in gene flow between concentrations of Ribbonsnakes in Nova Scotia. Results of this study will aid the Ribbonsnake recovery team in planning for the management and eventual recovery of this species in Nova Scotia.
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Todd, J. 2007. Ecology of the Eastern Ribbonsnake (Thamnophis sauritus) in a disjunct population in southwest Nova Scotia. MSc thesis. Dalhousie University, Halifax, NS.
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Abstract / Description:
In Nova Scotia the Eastern ribbonsnake Thamnophis sauritus is considered threatened under the Canadian Species at Risk Act because it is disjunct from the rest of the species range and populations in the region are believed to be small. There is a paucity of data on T. sauritus in Nova Scotia; this is a barrier to its recovery. A free-ranging population of T. sauritus in
In Nova Scotia the Eastern ribbonsnake Thamnophis sauritus is considered threatened under the Canadian Species at Risk Act because it is disjunct from the rest of the species range and populations in the region are believed to be small. There is a paucity of data on T. sauritus in Nova Scotia; this is a barrier to its recovery. A free-ranging population of T. sauritus in Nova Scotia was studied using visual surveys throughout their active season (March to November) in the years 2004-2006. Habitat was compared between two sites of high T. sauritus density. In a laboratory experiment the importance of reversing thermal gradients, water level rise, and circannual rhythmicity in spring emergence of T. sauritus in artificial hibernacula was investigated. The possibility of heterothermy (differing temperatures) along the snakes- bodies was investigated to determine if there was an abrupt difference in body temperature above and below the cloaca. Such a difference may indicate differential perfusion to the tail. Thamnophis sauritus were found hibernating in concentrated areas, and in exposed areas dominated by fractured rock within a floodplain. Mating was not observed; behaviour that could have indicated courtship occurred in both the fall and spring. Foraging was active. Tail pseudoautotomy was observed. The two sites where habitat was compared were disturbed from previous flooding and had large floodplains with slow water flow, and exposed and complex shorelines. In the laboratory T. sauritus came to the surface of hibernaculum under the influence of a thermal gradient or without manipulation, suggesting that both thermal and endogenous factors may play a role in emergence in this species at the northern limit of its range. While T. sauritus in the field had significantly colder tails than bodies, in the lab their tails were significantly warmer than their bodies.
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