MTRI is a non-profit co-operative with a mandate to promote sustainable use of natural resources and biodiversity conservation in the Southwest Nova Biosphere Reserve and beyond through research, education, and the operation of a field station.
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The Eastern Ribbonsnake (Thamnophis sauritus) is listed as 'Threatened' under both the federal Species at Risk Act and the Nova Scotia Endangered Species Act. Its range in Nova Scotia appears to be limited to the interior of southwest Nova Scotia, with the majority of sightings occuring in the Mersey and Medway watersheds. Little is known about this small, harmless, cryptic snake. Researchers are studying this snake to determine its range in Nova Scotia, its population structure, size and trends, and to identify threats. Threats include loss of habitat due to shoreline development, alterations to watercourses, being run over by vehicles on roads, tracks and trails, and being intentionally harmed by humans. Our limited understanding and lack of knowledge of its biology, distribution, and overwintering sites may be the greatest hindrance to its recovery.
Photo Credit: Wesley Pitts
The Eastern Ribbonsnake is a long, slender, semi-aquatic snake. It is black with three yellow stripes that run along its back and sides, and has caramel coloured lines below the yellow side stripes. It also has as distinguishing white, tear-drop shaped line in front of each eye.
They are typically found near the water's edge of freshwater wetlands including stillwater streams, lakes, marshes, swamps, bogs, and fens. In the winter, they hibernate underground. Our knowledge of its habitat is currently limited and research is on-going.
Photo Credit: Jeffie McNeil
Get involved! Become a steward, volunteer and report sightings!
Become a Steward: Stewardship is protecting and being responsible for something. Habitat loss is the most likely the primary reason why species become at risk. Learn how to maintain or recover healthy ecosystems and habitats for species at risk, and get involved with recovery actions. Learn more in our Healthy Lakes and Wetlands for Tomorrow: A Landowner Stewardship Guide for Species at Risk in Nova Scotia.
Volunteer: If you are interested in participating in Eastern Ribbonsnake surveys, give us a call at 902-682-2371 or email firstname.lastname@example.org. Surveys take place throughout the summer, but are more frequent in the spring (April - May) and the fall (September - October) in order to help identify overwintering sites.
Report Sightings: If you see a ribbonsnake, call the species at risk reporting line at 1-866-727-3447 (don't forget to leave your name and contact information), or report your sighting online at www.speciesatrisk.ca/sightings.
For more information, visit the Eastern Ribbonsnake pages on Nova Scotia's Species at Risk Conservation and Recovery website at www.speciesatrisk.ca, or our Healthy Lakes and Wetlands for Tomorrow: A Landowner Stewardship Guide for Species at Risk.
Eastern ribbonsnakes must find suitable underground sites to avoid freezing winter temperatures. However, it is not known if these sites typically occur within wetlands, at their edges or in adjacent terrestrial habitats. Knowing the characteristics of overwintering sites and their distance from the snake’s summer wetlands is crucial for critical habitat identification, identifying threats and developing management plans for this species, which is listed as Threatened both federally and provincially. In winter 2009, the first known ribbonsnake overwintering area in a terrestrial habitat was identified in Nova Scotia and this site has been monitored annually since its discovery to document long-term use, number of snakes and site fidelity. Efforts continue to locate additional overwintering sites through systematic surveys of upland areas adjacent to known concentrations of ribbonsnakes.
Photo Credit: Jeffie McNeil
Surveys occurred primarily in the habitats around Grafton Lake, Kejimkujik. Surveys took place regularly from early April to early May and occasionally in October and November.
Sites where snakes are found were revisited regularly to estimate the number of snakes using the site and the period of occupancy. Surrounding wetlands were visited occasionally during the active season to mark snakes and determine when they were moving.
Surveys were conducted by experienced biologists and trained volunteers and were aided by dogs trained to identify ribbonsnakes by scent.
Detailed data were recorded on search effort, weather conditions, geographic coordinates, habitat characteristics, snake behaviour and morphology.
Attempts were made to capture all detected ribbonsnakes. Snakes were individually marked by ventral scale clipping. Snakes were measured, weighed, photographed and released at the capture site.
Volunteers Harold and Diane Clapp found what is believed to be a new overwintering site, only the second known in the province.
The new site is on top of a beech dominated slope, approximately 200 m from water at Grafton Lake. Eight individual ribbonsnakes were found at this site over a two-week period in mid-April. One additional ribbonsnake was found at the same site in early October, providing more evidence that it is likely an overwintering site.
Ribbonsnakes once again returned to the previously known overwintering site, with five individuals encountered in spring and one in fall.
Photo Credits: Jeffie McNeil
Surveys took place from mid March to mid April and again from mid September through late November. Surveys occurred at 21 sites around four water bodies that were known to contain ribbonsnakes.
Habitats surveyed included eight primarily wooded sites, eight wetlands and five sites dominated by human made features (e.g. roadways, gravel pits, lawns).
Nine ribbonsnakes were found at the known overwintering site at Grafton Lake in 2012; four individuals in spring, four in fall and one in both spring and fall.
Several late October and early November Eastern ribbonsnake sightings were recorded at a woodland/wetland boundary on the north end of Grafton Lake, suggesting another possible overwintering site in this area. There were six sightings in this zone during the warm spell on November 12 and 13. Many of these snake sightings were young of the year, although a couple of large snakes were also observed.
Surveys took place from mid March to early May and again from early October to early December. Surveys occurred at 35 sites around seven water bodies that were known to contain ribbonsnakes.
Habitats surveyed included ten primarily wooded sites, eight wetlands, ten woodland-wetland interfaces and seven sites dominated by human made features (e.g. roadways, gravel pits, lawns).
Eight ribbonsnakes were found at the known overwintering site at Grafton Lake in 2011; one individual in the spring, and seven on the fall. One of the snakes had been previously captured in the wetland over 300 m away, providing the first confirmation that ribbonsnakes were coming to the overwintering site from the nearby wetland. Another snake had been caught at the overwintering site in 2009, confirming his fidelity to the area for two winters. The first neonate was observed at this site.
Several late fall and early spring sightings were recorded at a other locations, indicating the possibility of a nearby overwintering site or travel route. Four of these sightings occurred a considerable distance from water and were in a variety of habitats including an abandoned gravel pit, a lawn, a driveway and a paved road.
Photo Credits: Jeffie McNeil
Ongoing Project since 2009
Canadian Wildlife Federation
Mersey Tobeatic Research Institute
Eastern Ribbonsnake Recovery Team
Government of Canada through the federal Department of the Environment: Habitat Stewardship Program for Species at Risk
The Atlantic population of the Eastern ribbonsnake is listed as a threatened species under the federal Species at Risk Act by the Committee on the Status of Endangered Species in Canada (COSEWIC) and the Nova Scotia Endangered Species Act. As an ectotherm, this snake’s physiological activity and survival are highly dependent on environmental temperatures. Snakes are able to strategically move between warm and cool microclimates within their habitat in order to regulate their body temperature in response to changing environmental conditions. A better understanding of microhabitat and microclimate preferences of the ribbonsnake could improve our understanding about their movement patterns and thermal ecology. The ribbonsnake’s cryptic nature makes them difficult to locate in the field, so assistance from scent-trained sniffer dogs has been recently used as a non-invasive method to help find these individuals in the field. This exploratory study hopes that a better understanding of this species’ behaviour within microhabitats under various field conditions will improve monitoring and research strategies.
Continuation of the onging monitoring and mark-recapture surveys of the ribbonsnake population at Grafton Lake within Kejimkujik.
Improving knowledge concerning this species' microhabitat and microclimate preferenced, allowing better prediction of their movements under different weather conditions.
Improved prediction of snake movements under different conditions would allow better protection of wetland habitats at Grafton Lake against human disturbance through more strategic surveys when monitoring and researching ths species in the future.
Photo Credit: M. Thompson
Surveys were conducted in summer and fall at Grafton Lake within Kejimkujik. Snakes were located in the field by human visual surveys and scent-tracking assistance from conservation canines.
Mark-recapture procedures in the field aimed to collect a variety of information concerning snake characteristics, microhabitat elements, environmental temperatures and field conditions.
Snakes were marked using ventral scale clip codes and all snake sightngs were recorded on the Nova Scotia Species At Risk database.
Temperature field maps were designed at the North Side Flats section at Grafton Lake. The water's edge and forest's edge within this section were thermally mapped in order to monitor this semi-aquatic species' movements in summer and fal months. Time of day, air temperature, surface temperature and ground temperature were measured to build thermal gradient maps of this snake's microclimate.
The McGowan Bog was also surveyed on occasion to extend efforts to another population outside of Kejimkujik, however there was no snake sightings success in this area.
Photo Credits: J. Delle Cave and M. Thompson
Analysis is currently in progress and therefore results are pending.
It is predicted that comparisons between mapped environmental microclimates and preferred microclimates of snake will produce patterns that may allow for better prediction of snake movements under a variety of different weather conditions.
Single year project, 2013 (temperature mapping/microclimates)
2009 - 2013 (conservation canines)
Mersey Tobeatic Research Institute