Queensnake (Regina septemvittata) recovery strategy 2016: part 2

• Previous page
• Table of contents
• Next page

Part 2 - Recovery Strategy for the Queensnake (Regina septemvittata) in Ontario, prepared by Scott D. Gillingwater for the Ontario Ministry of Natural Resources

Ontario Recovery Strategy Series
Prepared under the Endangered Species Act, 2007
Queensnake (Regina septemvittata) in Ontario

Document Information

Recommended Citation

Cover illustration: Rob Tervo

Content (excluding the cover illustration) may be used without permission, with appropriate credit to the source.

Cette publication hautement spécialisée Recovery strategies prepared under the Endangered Species Act, 2007, n’est disponible qu’en anglais en vertu du Règlement 411/97 qui en exempte l’application de la Loi sur les services en français. Pour obtenir de l’aide en français, veuillez communiquer avec Pamela Wesley au ministère des Richesses naturelles au 705-755-5217.

Authors

Scott D. Gillingwater

Acknowledgements

The Ontario Ministry of Natural Resources (OMNR) provided financial support for the creation of this document.  Karine Beriault (OMNR) and Rhonda Donley (OMNR) provided technical assistance during the preparation of this strategy.  The Queensnake Recovery Team reviewed and offered suggestions on the content of this draft.

Declaration

The recovery strategy for the Queensnake has been developed in accordance with the requirements of the Endangered Species Act, 2007 (ESA).  This recovery strategy has been prepared as advice to the Government of Ontario, other responsible jurisdictions and the many different constituencies that may be involved in recovering the species.

The recovery strategy does not necessarily represent the views of all of the individuals who provided advice or contributed to its preparation, or the official positions of the organizations with which the individuals are associated.

The goals, objectives and recovery approaches identified in the strategy are based on the best available knowledge and are subject to revision as new information becomes available.  Implementation of this strategy is subject to appropriations, priorities and budgetary constraints of the participating jurisdictions and organizations.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy.

Responsible Jurisdictions

• Ontario Ministry of Natural Resources
• Environment Canada, Canadian Wildlife Service – Ontario
• Parks Canada Agency

Executive Summary

In Canada, Queensnake (Regina septemvittata) ) only occurs within southern Ontario and is the least reported snake species in the province due to both its rarity and cryptic behaviour.  Formerly found in approximately 26 localities in Ontario, it is now extant at about half of those sites.  It is listed as endangered by COSEWIC (Committee On the Status of Endangered Wildlife In Canada), threatened under the Species at Risk Act and endangered under Ontario's Endangered Species Act, 2007. 

Threats and limiting factors affecting this species include habitat loss and degradation, intentional and unintentional human-caused mortality, genetic isolation, habitat specialization, prey specialization, pollution and invasive species.

The long-term recovery goal is to halt further declines and to achieve stable or increasing populations of Queensnake in Ontario at all sites throughout the current distribution and, where and when feasible, at sites within the historic distribution that have suitable habitat.  In order to successfully recover this species, the following short term objectives have been established:

1. Increase knowledge of distribution, abundance, life history, and habitat needs of Queensnake in Ontario;
2. Determine population abundance and dynamics;
3. Maintain/enhance the quantity and quality of Queensnake habitat;
4. Inventory crayfish diversity at each extant and historic Queensnake location, investigate diversity, relative abundance, habitat needs and the presence of the exotic Rusty Crayfish;
5. Investigate the feasibility for supplementation or reintroduction of Queensnake to parts of its current and historic range;
6. Reduce or mitigate threats to Queensnake and its habitat where feasible;
7. Coordinate recovery efforts with appropriate conservation groups to protect individuals, and to maintain or recover populations and habitat;
8. Provide awareness and educational resources to individuals and communities living near extant Queensnake populations or using extant Queensnake locales for recreation.

Recovery should be accomplished by reducing mortality through the protection and maintenance of vital aquatic and terrestrial habitats, restoring degraded habitat, preventing the loss of the primary food source and through public education and awareness. 

It is recommended that the area prescribed as habitat in a habitat regulation for Queensnake include the extent of known terrestrial and aquatic habitat within all remaining sites where the species persists.  We recommend prescribing Queensnake habitat as the area 250 m up and down stream from each occurrence, and 30 m from the high water mark on each side of the water course along this area.  Where the shoreline is not immediately apparent, an area of 250 m in all directions from the observation should be included.  Also, all terrestrial and aquatic habitat within 50 m of all foraging, hibernacula, thermoregulation, parturition and shedding sites that do not lie within 30 m of the high water mark should be prescribed as habitat in a habitat regulation.  This would provide protection for hibernation, gestation, parturition, thermoregulation, shedding and foraging habitats, as well as habitat for prey (i.e., crayfish).  If re-introduction is considered feasible, recovery habitat should also be defined in the habitat regulation.   

1.0 Background Information

The glossary provides definitions for the abbreviations above.

1.2 Species Description and Biology

Species Description

The Queensnake (Regina septemvittata) is a slender, moderately sized, semi-aquatic snake of the family Colubridae, with keeled scales and a divided anal plate (Conant and Collins 1998).  Dorsally, the colour is brownish olive with three narrow black stripes running longitudinally down the midline and along each side on the fifth and sixth scale rows.  The dorsal stripes are less apparent in older individuals and the belly stripes often become mottled with age (Gillingwater pers. obs.). The belly is pale yellow with four dark longitudinal stripes (Smith 1999).  Queensnake is the only Ontario snake that has a longitudinally striped underside.  Queensnake can attain a length of up to 90 cm, but is generally in the range of 40 to 60 cm.  There are no subspecies of Queensnake throughout its range in the eastern North America (Crother et al. 2008). 

The non-venomous Queensnake is harmless to humans but if handled will often writhe and exude a strong-smelling liquid from the cloaca.  It is a strong swimmer and is usually found in, or in close proximity, to water (Froom 1981).  It is most commonly associated with rocky creeks and rivers, but may sometimes be found in marsh and wet meadow habitats.  It feeds almost exclusively on freshly moulted crayfish (Conant and Collins 1998).

Species Biology

The Queensnake is viviparous, with no distinguishable eggshell formation during any point of development (Branson and Baker 1974). The young are born between July and September (Campbell and Perrin 1979, Froom 1981, Behler and King 1988). Both a gestation and parturition site are necessary for embryo development and birthing respectively, though gestation sites may also be used for birthing (Gillingwater 2009).

Branson and Baker (1974) found that female Queensnakes in Kentucky did not normally reproduce until their third year, whereas males matured during their second year. Maturity may be further delayed in Ontario due to a shortened active season compared to Kentucky. Successful copulation may take place in both the spring and fall. No maternal care has been noted and no information is available on the frequency of reproduction.

The reported active season for Queensnake in Ontario is generally shorter than has been described for southern portions of the American range. In Ontario this species has been observed as early as April 15 (Piraino and Gillingwater 2003), and as late as October 16 (M.J. Oldham, pers. comm.). In Ohio, activity has been reported from April to September (Conant 1938a) similar to the Ontario range, with the exception of a single report of a Queensnake found in January atop the ice of a creek (Conant 1938b). Observations of aggregations of Queensnakes in the late fall (Wood 1944, Neill 1948, Wood 1949, Wood and Duellman 1950), and in the early spring (Gillingwater 2002, Gallagher 2003 pers. comm., Piraino and Gillingwater 2003) in both the United States and Canada have been reported.

Queensnake is a prey specialist, dependent primarily on freshly moulted crayfish for survival (Raney and Roecker 1947, Judd 1955 and 1962, Branson and Baker 1974). Crayfish populations are not likely affected to any extent from Queensnake depredation, especially in Ontario where Queensnake populations are quite small. Campbell and Perrin (1979) found that the predominant crayfish species at Queensnake sites in Ontario was Orconectes propinquus, though other crayfish species are consumed throughout the species' North American range. Queensnake has been found to consume other prey items, including small fish, albeit on an irregular basis (Surface 1906, LeRay 1928, Conant 1938a, Raney and Roecker 1947, Wood 1949, Adler and Tilley 1960). Although few data exist on feeding behaviour in the field (Wood 1949), this species has been found to either forage among stones and detritus in swift, shallow water or to remain motionless, with only the head exposed in calm pools (Raney and Roecker 1947, S. Gillingwater pers. obs.). Wood (1949) observed a Queensnake scavenging a dead crayfish and Ernst and Ernst (2003) observed Queensnakes flushing out freshly moulted crayfish and consuming them tail first.

1.3 Distribution, Abundance and Population Trends

The distribution of Queensnake extends from southwestern Ontario, southwestern New York, and southeastern Pennsylvania, south to the Gulf Coast at the Florida/Alabama border; west to southeastern Wisconsin and eastern Mississippi. Additional records also exist from northern Michigan, southwestern Mississippi, Arkansas and southwestern Missouri (Conant and Collins 1998) (Figure 1). The Canadian range of the species is currently restricted to southern Ontario where it occurs discontinuously west of the Niagara Escarpment, from northern Bruce Peninsula south to Lake Erie and west to Essex County. The former range may have extended east to Toronto, but no specimens have been found in this area since the mid-1800's (Lamond 1994), and the original observation may be in error.

Figure 1. Queensnake North American Distribution Map (Map courtesy of the Natural Heritage Information Centre)

Figure 2.Distribution of the Queensnake in southern Ontario where hatched areas represent historc records (over 20 years old) and solid areas represent recent records (less than 20 years old) (based on NHIC 2010).

The Queensnake was designated endangered in 2010 by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), but currently remains listed as threatened under the federal Species at Risk Act as of January 2011. This species was originally listed as threatened under the Endangered Species Act, 2007 (ESA), but was uplisted to endangered on September 28, 2010. It currently receives species and habitat protection under the ESA. Queensnake has been listed as a specially protected reptile under Ontario's Fish and Wildlife Conservation Act, 1997 since January 1, 1999.

Queensnake is relatively widespread in the United States and ranked as globally secure (G5) (Table 1). Canada's population represents less than five percent of the global population.

Relatively little is known of this species throughout its entire global range; therefore an estimate of global population size is unavailable.  Similarly, no formal studies have been conducted to determine absolute population size in Ontario.  Localized distribution at surveyed sites suggests limited dispersal.  Branson and Baker (1974), through a mark-recapture study, found that this species had relatively small home ranges, with most individuals not moving more than 30 m from their original point of capture, though one individual moved 122 m over a two week period.  At one Ontario site on the Thames River, movements of 100 m were typical between hibernation and gestation sites (Gillingwater 2009), with movements of up to 250 m recorded (Gillingwater unpub. data).

The Queensnake has always been considered uncommon in Ontario (LeRay 1928, Mills 1948, Logier 1958, Campbell 1977, Oldham 1986, Lamond 1994).  It appears relatively abundant at some locations, yet very rare or absent from other seemingly adequate areas (Spurr 1978, Gillingwater 2008).  Queensnake abundance, behaviour and habitat use in a given area is also subject to change throughout the active season as snakes move between hibernacula, foraging grounds and thermoregulation/gestation sites (Gillingwater 2002, Piraino and Gillingwater 2004), making estimation of abundance difficult.  The overall scarcity, cryptic behaviour and aquatic habits make assessment of populations difficult.  Queensnake has thin skin with limited elasticity (compared to other Ontario snake species of similar size), and frequent movements throughout a rocky terrain has been noted to cause abrasions on lumps under the skin (e.g., PIT tags and likely radio tags).  Queensnake is also exceptionally stress and heat intolerant compared to other mid-sized snake species, rapidly showing signs of distress (i.e., open mouth breathing, fatigue and unresponsiveness) and thus may not serve as a good candidate species for telemetry research (Gillingwater pers. obs.).  Only one location has been sampled intensively or consistently enough to derive a rough estimate of population size. A population of approximately 50 adults were located in open habitat (very little canopy cover) along a 200 m section of the North Thames River (Gillingwater 2002, Piraino and Gillingwater 2004).  No additional animals were found outside of this area despite frequent surveys each season.  Survey methods included intensive timed surveys and PIT (Passive Integrated Transponder) tagging.  Despite a number of surveys across the province, all Ontario studies suggest low population density, limited local distribution, little potential for individuals to migrate between populations and an overall declining trend. 

The Queensnake is one of the least reported snake species in Ontario (based on the number of records in the NHIC database) with only 29 element occurrences (NHIC 2010).  Results of frequent surveys within the Thames River Watershed over the past 15 years suggest that some Queensnake populations may have been lost as recently as 2002 (Gillingwater 2002, Gillingwater 2009) and others throughout much of Ontario have not been observed for over 40 years (Campbell 1977, Fletcher and Gillingwater unpub data 1997).  Queensnake was recorded along the Canard River in 1985 (Oldham 1986), with additional sightings in 2002 (Waldron pers. comm. 2003).  In 2009, observations on Fighting Island in the Detroit River were also recorded (Jones pers. comm. 2009).  Francis and Campbell (1983) rediscovered Queensnake in the Waterloo region after a 50-year absence of recorded sightings.  This finding is more likely the result of inadequate or infrequent surveys over the time interval.  Populations along the Bruce Peninsula may have been lost, in particular at Scugog Lake, where the species has not been reported since 1927, and at Baie du Doré, where it was last seen in 1969.  A Queensnake was encountered near Emmett Lake in the central part of Bruce Peninsula National Park in 2005, and subsequent surveys from 2006 to 2008 resulted in a small number of new observations (Brinker 2007, Jalava 2009).  Unsuccessful surveys were also conducted at the historic Scugog Lake and Cameron Lake sites over the same period (Jalava 2009).  A Queensnake was reported at Baptist Harbour (northwest end of the Bruce Peninsula) in 2003, but subsequent surveys in 2008 were unsuccessful (Jalava 2009). 

1.4 Habitat Needs

During a study in Ohio, Wood (1949) summarized the habitat necessary for the subsistence of Queensnake in a given area.  The following three conditions were deemed necessary: a permanent body of water, still or flowing, with temperatures at or above 18.3°C for the majority of the active season; an abundance of cover material, such as flat rocks submerged and/or found along the bank; a large population of crayfish.  These features are present at most sites occupied by Queensnake in Ontario, but at outer Long Point, Walpole Island and Lake St. Clair, rocky cover of this sort is rare or absent, and the species may use crayfish (e.g., Cambarus diogenes, Orconectes immunis and Fallicambarus fodiens) burrows for cover.  Additionally, shoreline vegetation is commonly used for thermoregulation at many sites.

Queensnake is commonly associated with rock or gravel bottomed streams or rivers (Duellman 1951, Conant 1960, Oldham 1986, Johnson 1989, Gillingwater 2002).  The types of streambed substrates reported to be associated with Queensnake vary, but the most commonly noted includes limestone (Wood 1949) and slate (Triplehorn 1949).  This species may be less commonly encountered in other habitats such as marsh (Conant 1960), ponds (Wood and Duellman 1947), lakes (Duellman 1947) and quarries (Mattison 1995).  Some Ontario records include the shorelines of large lakes such as Long Point on Lake Erie.  However, most snakes occur in the extensive inland marshes/meadows rather than the Lake Erie shoreline itself.  In addition, one population on the Bruce Peninsula occurs among rocky meadow marsh shorelines on small inland lakes which may dry up in summer (Jalava 2009). 

The Queensnake is a highly aquatic species rarely venturing far overland. During the active season, it is usually confined to within three to five metres of a shoreline (Campbell and Perrin 1979, Gillingwater 2008, M. Fletcher pers. comm. 2004, K. Vlasman pers. obs. 1997). Of 185 Queensnake captures along the Thames River by Piraino and Gillingwater (2007), 177 (96%) were located within 5 m of the river's edge and the remainder were found up to 15 m from the water at a hibernaculum.  Calm waters, such as small pools along creeks and rivers, appear to be necessary for foraging behaviour, cover and possibly thermoregulation (Gillingwater, unpub. data).  Since the Queensnake relies almost exclusively on crayfish as a food source, Queensnake habitat must include features that support crayfish.  Queensnake is often associated with shrubs and trees along the shores of rivers and streams, where they bask on overhanging branches (Campbell and Perrin 1979, Layne and Ford, 1983; Ernst and Barbour 1989; Gillingwater 2008).  Campbell and Perrin (1979) found Queensnakes in southwestern Ontario in close association with willow (Salix spp.) and Eastern Cottonwoods (>Populus deltoides) as well as herbaceous meadow marsh species, but snakes avoided shorelines with a heavy canopy.  The area occupied by one Queensnake population along the Thames River was open to sunlight for approximately eight hours a day; rocks covered portions of the shore, along with open clay areas, low-lying broad-leafed plants, grasses, and scattered shrub willow (Gillingwater and Piraino 2002).  Queensnakes used both natural items (e.g., shoreline rocks, bank overhang) as well as anthropogenic features such as geotextile for cover, thermoregulation, gestation, shedding and parturition (Gillingwater 2009; Gillingwater unpub. data). 

Hibernacula are critical for over winter survival (Bauchot 1994; Mattison 1995), and thus represent one of the most important habitat features for this species in Ontario.  In Ontario, a single hibernation site has been located along the Thames River. It occurred along a seepage area on an open south-facing clay slope above the river's high water mark.  Both a small mammal burrow and openings along tree roots provided access to the hibernaculum (Gillingwater 2009).

1.5 Limiting Factors

Prey specialization, limited home range size and reliance on a narrow band of shoreline habitat for survival, taken collectively rather than distributively, increase susceptibility to stochastic events.  While the viviparous method of reproduction may be beneficial for a mainly aquatic species (Hall 1969) within a northern range, it may also leave the female susceptible to additional threats while on land during gestation (Greene 1997; Gillingwater 2002).  Additionally, the amount of energy involved in this mode of reproduction may also draw heavily on energy stores (Greene 1997). 

The small population sizes, gaps between populations and general rarity of the species may limit migration between populations, likely resulting in genetic isolation. Prey specialization, permeable skin (which results in rapid dehydration) and reliance on water may limit inland movements and dispersal outside of watershed boundaries, further contributing to genetic isolation and reduced gene flow.  Current Ontario Herpetofaunal Summary data reveal the scattered and isolated nature of Queensnake populations occurring throughout southwestern Ontario.  Such isolation may leave each of the remaining populations vulnerable to inbreeding depression, demographic and environmental stochasticity, and changes in habitat/food supply.  Under these circumstances, individuals may have limited opportunity to move to more suitable areas (Campbell and Perrin 1979, Fletcher and Gillingwater unpub. data 1997; Gillingwater 2002). 

Specificity for certain features required for overwintering may limit Queensnake.  Although no specific data for Queensnake are available, long hibernation cycles may harm some individuals.  Extremely cold winters and the inundation of water within a hibernation site have been found to cause mortality in other snake species during hibernation (Bauchot 1994, Mattison 1999).  Northern snake species may also be susceptible to increased levels of environmental exposure and predation upon emergence in early spring (Porchuk 1996, Mattison, 1999). 

1.6 Threats to Survival and Recovery

The following threats to survival and recovery are not in listed in order of significance.

Habitat Destruction, Degradation and Fragmentation

Habitat loss, fragmentation and degradation are the biggest threats to Queensnake in Ontario (Cook 1970, Smith 1999, Gillingwater 2008).  The already limited range and small size of remaining habitat used by Queensnake is further compromised by changes in the composition of the landscape.  Such changes can affect spatial and activity patterns of the Queensnake and limit the capacity of a region to support all ecological needs of the species.  Retaining the appropriate habitat composition for both Queensnake and crayfish, their primary food source, is necessary to ensure the long term viability of this species. 

The four primary threats to Queensnake habitat include:

1. the absolute loss of specific habitats (e.g., hibernation sites),
2. an alteration in the relative proportions or configuration of the habitat features or
3. the fragmentation of habitat features with roads and other barriers, and
4. transformation of vegetation or ecological function of the habitat through invasion by non-native plant species (e.g. European Common Reed).

In the intensively cultivated landscape of southwestern Ontario, natural riparian habitat is often eliminated or reduced to narrow fragments along river banks.  Habitat has remained only because some of the rivers are associated with steep valley slopes where agriculture has not been possible.  In places, livestock has been allowed free access to rivers and streams causing rutting, erosion, sedimentation, excessive nutrients, and removal of vegetation cover through overgrazing.  The loss of suitable habitat for Queensnake through direct physical destruction from cattle along riparian zones has been documented by Homyack and Giuliano (2002).  Campbell and Perrin (1979) noted that agricultural development severely altered creeks and marshes near Lake St. Clair, making the habitat unsuitable for Queensnake.  Any type of land use that extends to the edge of a waterway can be detrimental if the cover and structure that form important habitat for Queensnake are removed.  Additionally, the drainage of wetlands, eutrophication due to livestock or poultry waste runoff into streams, overuse of water resources by human recreational activities, and large impoundments can all negatively affect Queensnake populations (Natureserve 2010).  Hamr (1998) documented the recent decline of Orconectes propinquus throughout Ontario watersheds, possibly due to competition with Orconectes rusticus, a non-native species, and from air and water pollution, sedimentation and potentially water velocity.

In some urban areas, development on lands surrounding the floodplain can increase surface water drainage from storm sewer outfalls.  Runoff can degrade riparian Queensnake habitat through sedimentation, siltation, erosion, contamination, and greater changes in river levels (Gibbons and Dorcas 2004).  In addition, channelization, bridges and erosion control structures further limit natural habitat by replacing natural shoreline with gabion baskets, concrete walls, and rip-rap. Although legally protected in Missouri, the Queensnake has been extirpated from the state due to habitat loss from the construction of dams (Conant 1960, Anderson 1965, Ashton 1976).  Dams, urban discharge, water use and other anthropogenic alterations can cause changes in the hydrology of southern Ontario rivers, likely affecting all riparian species through reduced base-flows and/or rapid influx of water.

Invasive plants such as European Common Reed (Phragmites australis ssp. australis) and Purple Loosestrife (Lythrum salicaria) may limit use of current sites in the long term.  European Common Reed has rapidly expanded through much of southwestern Ontario in recent decades, now dominating many systems including some sites inhabited by Queensnake such as along the St. Clair, Long Point and Big Creek National Wildlife Areas and Nanticoke Creek (Gillingwater pers. com.).  The European Common Reed has been noted to have reduced thermoregulation habitat of Queensnake in Ohio (Bekker 2007).  Plant succession, which creates a heavy canopy cover from large shoreline trees, can shade out existing Queensnake habitat (Gillingwater 2009).  In some cases, adjacent habitat has been lost already, leaving few areas for safe recolonization of snakes retreating from natural and invasive plant succession.

Intentional Human-caused Death or Disturbance

Queensnakes, although infrequently encountered in Ontario, are at risk from direct human persecution.  Campbell and Perrin (1979) and Spurr and Smith (1979) found dead Queensnakes that had apparently been bludgeoned to death by humans.  In the United States, Queensnake are often encountered and killed by anglers fearing a loss of game fish to the reptile (Harding 1997), and Ernst and Ernst (2003) note the killing of many individuals by gun.  Negative attitudes toward snakes are common throughout North America, and even harmless species such as garter snakes are routinely killed (Gillingwater, pers. obs.) out of fear or ignorance.  Due to the rarity of the species, they are susceptible to collection as pets, or may suffer mortality or habitat disturbance through the photographic pursuits of keen naturalists and reptile enthusiasts (Gillingwater pers. obs.).

Unintentional Human-caused Death or Disturbance

Recreational use (hiking, angling, ATV use, horseback riding etc) can negatively affect Queensnake and associated habitats. People moving along shorelines may inadvertently alter gestation, foraging and thermoregulation habitat through shifting or compacting rocks and other cover items. This is of particular importance to Queensnakes because they demonstrate strong fidelity to cover items.  In some areas, activities as seemingly benign as anglers moving across the habitat could cause long-term disturbance to gestation and thermoregulation sites and has resulted in the direct mortality of snakes through crushing injuries beneath rocks (Gillingwater 2008). In areas frequented by anglers along the Thames River and the Grand River, Queensnakes have been found dead and others have been found with crushing injuries to the head (Gillingwater 2008). Gestation sites have also been heavily disturbed along the Thames River, often repeatedly trodden upon, set on fire or displaced (S. Gillingwater pers. obs.). Although the majority of disturbances and mortalities are likely inadvertent, the effects of even moderate recreational use along sensitive sites can be devastating.

Pollution

The impact of pollution on Queensnake is not well understood, though water contamination from agricultural practices, direct urban runoff from larger cities such as London and Cambridge, and chemical spills are likely.  Since Queensnakes have exceptionally permeable skin, they may be more susceptible than other snake species to pollutants within their aquatic environments (Stokes and Dunson 1982, Hulse et al. 2001, Gibbons and Dorcas 2004).  A rapid decline in Ontario's already limited Queensnake populations could occur as a result of a decline or loss of crayfish.  Regardless of species, all crayfish can be negatively affected by sedimentation, siltation, and pollution (Hamr 1998, David et al. 1994, Brie et al. 2009).  During a study in Alberta, the crayfish species >O. virilis was found to bio-accumulate mercury (Vermeer 1972), a trait likely shared by other species in the genus. 

Invasive Wildlife

Invasive species may also contribute to the destruction and fragmentation of Queensnake habitat.  The Common Carp (Cyprinus carpio) is known to increase turbidity and alter natural processes in aquatic environments (Parkos III et al. 2003).  At one site along the Thames River, Zebra Mussels (Dreissena polymorpha) heavily encrust rocks formerly used for cover and foraging by Queensnakes.  The mussels create a physical barrier restricting access between and under many large rocks, and also create a potential hazard with the sharp margins of their shell (Gillingwater 2009).  In Ohio, a large Queensnake population mostly disappeared between 2001 and 2004 due to the invasion by Round Goby (Neogobius melanostomus) (Bekker 2007), possibly due to heavy predation on crayfish populations (Davis 2003).  The Rusty Crayfish (O. rusticus) has yet to fully occupy the Ontario range of the Queensnake and interactions between the two have consequently not yet been studied.  The potential impact on Queensnake in Ontario through displacement of native crayfish species by the invasive exotic Rusty Crayfish is not yet understood.

1.7 Knowledge Gaps

Current Distribution and Population Trends

• Recent survey data for most extant and historic Queensnake sites are unavailable.
• At most sites, information is needed to better assess the condition of existing populations, to confirm the extirpation of apparently lost populations and to maintain consistent long-term data on Queensnake at extant sites.
• A standardized protocol for surveying and monitoring has not yet been developed.

Natural Life History Information

• Information on reproductive success, thermoregulation and gestation needs, foraging behaviour, prey selection, prey density limitations, home range size, seasonal movements and habitat selection and use is generally lacking.

Habitat Needs

• Detailed habitat information is lacking at most sites, especially detailed information on hibernacula, natural gestation sites and parturition sites.
• Additional ecological and habitat information for all life stages of this snake is lacking from most sites.

Genetic Isolation and its Effect on Populations

• It is unknown if inbreeding depression is a concern in isolated populations or if there is a strong relationship between extant populations in Ontario and elsewhere in its continental range.

Effects of Invasive Species

• Information on the threat of invasive plants and animals on the Queensnake and its habitats is lacking.  It is unknown if introduced wildlife such as Rusty Crayfish, Round Goby and Carp have negative effects on the Queensnake and its habitat in Ontario.
• Invasive plant species (e.g., European Common Reed) appear to be causing habitat loss and fragmentation at existing sites, but no empirical data are available at this time.

1.8 Recovery Actions Completed or Underway

Species Reporting and Distribution

The Ontario Herpetofaunal Summary database (Oldham and Sutherland 1986, Oldham 1988, Oldham and Weller 1989, Oldham unpub. data, Ontario Herpetofaunal Summary) contains the most complete history of Queensnake sightings and distribution in Ontario.  The data provide an opportunity to track available Queensnake records from both single encounters and research studies, in order to better monitor distribution and range in Ontario.  These data, housed and updated through the Natural Heritage Information Centre (NHIC) should continue to aid in recovery efforts and provide a valuable resource for planners and biologists. 

The Ontario Reptile and Amphibian Atlas project has recently been established to solicit reptile and amphibian sightings from researchers and the public across Ontario.  These observations will also be included in the NHIC database. 

Through funding from the Sault Ste. Marie Invasive Species Partnership Fund, the development of an Ontario Stream Assessment Protocol for Crayfish was recently initiated by Scott Reid (OMNR Aquatic Research), Eric Snyder (OMNR Invasive Species/Biodiversity) and Keith Somers (MOE Dorset).  This protocol would assist in tracking crayfish across the province, including areas where Queensnake are known, or were known, to occur.

Surveying of Historic Queensnake Sites

A number of surveys have been conducted for Queensnake throughout southern Ontario.  They have provided some of the only information available on Queensnake in Canada.  Although the majority of these surveys were short term, they suggest a decline of this species throughout Ontario over time, highlighting local extirpations and changes in habitat (Judd 1955, Judd 1962, Campbell 1977, Campbell and Perrin 1979, Spurr and Smith 1979, Gartshore and Carson 1990, Lamond 1994, Fletcher and Gillingwater unpub. data 1997, OMNR 2003 - 2005, K. Vlasman pers. comm., D. Jacobs pers. comm., Piraino and Gillingwater 2003, Piraino and Gillingwater 2004, Piraino and Gillingwater 2007, Gillingwater 2008, Gillingwater 2009, Gillingwater unpub. data 2002-2009).

Biological and Ecological Research and Monitoring

Very little in-depth research has been conducted on Queensnake in Canada.  Judd (1955, 1962) conducted a short-term study on the stomach contents of this species from a section of the Ausable River and a tributary of the Thames River.  Campbell (1977) and Campbell and Perrin (1979) investigated some aspects of habitat, distribution, ecology and biology of the Queensnake in Canada.  From 2002 to 2010, the first long-term study of a Queensnake population in Ontario was initiated along a section of the Thames River.  Through a mark recapture program utilizing PIT tags, new information on this species' natural history and habitat in Canada was collected (Gillingwater 2002, Piraino and Gillingwater 2003, Piraino and Gillingwater 2004, Gillingwater 2009,).  Guelph District MNR surveyed a population along a tributary of the Grand River, using PIT tags as a mark recapture tool as recently as 2003 (K. Vlasman pers. comm.).  The data from these studies have been used throughout this document.  Creation of artificial gestation, parturition, shedding and thermoregulation habitat using geotextile, and the rehabilitation of natural habitat through the removal of debris and non-native vegetation has been ongoing since 2002 along a section of the Thames River.  Initial efforts over the first eight years have proven successful, with further efforts continuing each season (Gillingwater 2009).

Recovery Teams

In addition to the efforts of the Queensnake Recovery Team, several multi-species and ecosystem-based recovery teams have incorporated Queensnake and its habitat requirements into recovery plans, including recovery teams for the Ausable, Grand and Thames rivers.  These teams have been assembled to assess and recover many aspects of the aquatic habitats that Queensnakes and other aquatic at-risk species require for survival.  Crayfish habitat is likely to benefit indirectly from these recovery initiatives.  A continued long-term partnership among these recovery teams could be mutually beneficial from both economic and logistical standpoints.

Public Education and Awareness

Until 1997, efforts to further Queensnake awareness and education in Ontario were limited at best, with only occasional newspaper and newsletter articles and fact sheets available to the public (Judd 1962, McBride 1967, Spurr 1978, Oldham 1986, Oldham 1988).  In 1997, a single page black and white fact sheet was created to further promote the species and complement survey efforts.  This fact sheet was also included in a landowner stewardship package.  In 2002, a full colour Queensnake fact sheet was developed as part of the Reptiles at Risk in the Thames River series.  A full colour poster including the Queensnake was also developed in order to solicit public sightings within the Thames River watershed (Gillingwater 2002).  As part of the ongoing Thames River Rare Reptile Research and Education Program, various talks, workshops and community displays continue to be delivered (2002-2010).  Additionally, efforts by the Toronto Zoo, Upper Thames River Conservation Authority, Lower Thames Valley Conservation Authority, Maitland Valley Conservation Authority, Ausable Bayfield Conservation Authority, Grand River Conservation Authority, Carolinian Canada and the Ausable and Thames River ecosystem-based recovery teams have further promoted awareness of Queensnake through species at risk posters, web-sites and community interaction. 

2.0 Recovery

2.1 Recovery Goal

The long-term recovery goal is to halt further declines and to achieve stable or increasing populations of Queensnake in Ontario at all sites with extant occurrences throughout the current distribution and, where and when feasible, at sites within the historic distribution that have suitable habitat. 

2.2 Protection and Recovery Objectives

2.3 Approaches to Recovery

2.4 Area for Consideration in Developing a Habitat Regulation

Under the ESA, a recovery strategy must include a recommendation to the Minister of Natural Resources on the area that should be considered in developing a habitat regulation. A habitat regulation is a legal instrument that prescribes an area that will be protected as the habitat of the species. The recommendation provided below by the author will be one of many sources considered by the Minister when developing the habitat regulation for this species

It is recommended that the area from the centre of the occupied water course to 30 m inland from the high water mark on each side of the water course be prescribed as habitat in a habitat regulation for each known Queensnake occurrence. A distance of 30 m is recommended to protect subterranean habitat, especially near hibernacula.  It should also compensate for fluctuating water levels and subsequent loss of wet meadow habitat.  For all meadow or wetland areas used by Queensnakes where a defined shoreline is not immediately apparent, it is recommended that the prescribed area encompass the extent of the meadow/wetland area within 250 m in all directions for each Queensnake observation.   This should incorporate all features that the species depends on for hibernation, gestation, parturition, shedding, thermoregulation and foraging, as well as areas for movement (i.e., corridors) between sites.  

The prescribed area should extend 250 m upstream and downstream (i.e., 500 m total) from each known Queensnake occurrence.  Branson and Baker (1974) observed that Queensnakes in Kentucky had relatively small home ranges with movements ranging from under 30 m to 122 m from their original point of capture over a two week period. In Ontario, most movements appear to be within 100 m over the active season (Gillingwater 2009), but observations of 250 m have been recorded (Gillingwater unpub. data).  Without the ability to safely use radio-telemetry to quantify extent of movement and home range size, a cautionary approach should be taken to ensure seasonal movements will not place the species in harm's way.  Thus, a 500 metre area of shoreline habitat is recommended for each Queensnake occurrence.

Occurrences should include recently confirmed records (within the past 20 years) as well as sites without a confirmed observation within the past 20 years. Provided the necessary tests are met (e.g., suitable habitat and conditions to ensure a viable population, and ability to be re-colonized or concrete plans to re-introduce the species to historic sites or previously unoccupied sites within the historic range or suitable areas for translocation), it is recommended that such recovery habitat receive protection through habitat regulation. 

It is recommended that terrestrial and aquatic habitat within 50 m of all Queensnake foraging sites, hibernacula, thermoregulation sites, gestation sites, parturition sites and shedding sites be prescribed as habitat in a habitat regulation, where it does not already fall within 30 m of the high water mark of a water body. This area is important for retaining the biological composition, structure and function of the surrounding and subterranean environment. For example, it could maintain connectivity between hibernacula and the shoreline of the adjacent water body.

Foraging, parturition, gestation, hibernation, shedding and thermoregulation areas, both natural and anthropogenic, should be included in the area prescribed as habitat for the extent of the feature's life. Both natural and artificial habitat may be used by the species, especially for thermoregulation and gestation (Gillingwater and Piraino 2002, Gillingwater 2009). The gestation site must provide a sufficient microclimate to ensure proper embryonic development while still offering some protection for the female.  A nearby, secure parturition site, if the gestation site is not used for parturition, is also necessary for birthing. Based on recent findings, parturition sites provide cover, are adjacent to the water's edge, maintain high humidity and appear to provide protection from excessive heat and predators (Gillingwater 2009).  Geological features used for these processes may remain indefinitely (e.g., fissures in bed rock), while anthropogenic (e.g., foundations) or organic features (e.g., rotting tree roots) may naturally decompose over a shorter span of time.

Only a single hibernation site has been described in Canada for this species (Gillingwater 2008, Gillingwater 2009), and thus the prescribed area is necessary to safeguard additional hibernacula and other significant habitat features that lie within the areas currently occupied by the species. Hibernacula are the most important habitat feature for the species' survival (Bauchot 1994, Mattison 1995), though they are difficult to identify due to: the small hibernacula entrance points; the subterranean nature of hibernacula; a limited ability to effectively use radio telemetry on this species; a strong likelihood that such habitat features exist on private lands; and the rarity and cryptic habits of the snake during ingress and egress to and from hibernacula. 

As a prey specialist, losses in crayfish will likely result in snake declines. The above recommendation would encompass some crayfish habitat, both along various water courses, and within meadow and wetland habitats.

References

• Adler, K.K., and S.G. Tilley.  1960.  A fish and a snail in the diet of Natrix septemvittata (Say).  Journal of the Ohio Herpetological Society 2: 28-29.
• Anderson, P.  1965.  The Reptiles of Missouri.  University of Missouri Press, Columbia, Missouri.  330 pp.
• Ashton, R.E. Jr.  1976.  "Endangered and Threatened amphibians and reptiles in the United States."  Society for the Study of Amphibians and Reptiles Herpetological Circular No. 5.  65 pp.
• Bauchot, R. (editor).  1994.  Snakes: A Natural History.  Sterling Publishing Co., Inc. New York.
• Behler, J. L. and F. W. King. 1988. The Audubon Society Field Guide to North American Reptiles and Amphibians. Chanticleer Press, Inc., New York.
• Bekker, K.A.  2007. Comparative Growth and Demographics of Two Sympatric Natricine Snakes.  MSc Thesis, Bowling Green State University, Kentucky
• Branson, B. A. and E. C. Baker. 1974. "An Ecological Study of the Queen Snake Regina septemvittata (Say) in Kentucky." Tulane Studies in Zoology and Botany 18(4):153-171.
• Brie A. Edwards, Donald A. Jackson, Keith M. Somers. 2009. Multispecies crayfish declines in lakes: implications for species distributions and richness. Journal of the North American Benthological Society: September 2009, Vol. 28, No. 3, pp. 719-732.
• Brinker, S. 2007. Hydro-riparian Species at Risk Inventory – Bruce Peninsula National Park. Prepared for Parks Canada Agency, Bruce Peninsula National Park, Tobermory Ontario. Dougan and Associates Ecological Consulting and Design. 84 pp.
• Campbell C.A.  1977.  The range, ecology and status of the queen snake (Regina septemvittata) in Canada.  Unpublished manuscript, KIZ10-6-5293 for Canadian Wildlife Service.
• Campbell, C. A. and D. W. Perrin. 1979. A Survey of the Queen Snake (Regina septemvittata) In Southwestern Ontario. Report to Wildlife Branch Ministry of Natural Resources, Ontario Government.
• Conant, R. 1938a.  "On the seasonal occurrence of reptiles in Lucas County, Ohio."  Herpetologica 1:137-144.
• Conant, R. 1938b.  "The Reptiles of Ohio."  American Midland Naturalist 20: 1-200.
• Conant, R. 1960. "The Queen Snake, Natrix septemvittata, in the Interior Highlands of Arkansas and Missouri, With Comments Upon Similar Disjunct Distributions." Proc. Acad. Nat. Sci., Phila., 112(2): 25-40.
• Conant, R. and J. T. Collins. 1998. Reptiles and Amphibians: Eastern/ Central North America. Houghton Mifflin Company, New York.
• Cook, F.R. 1970.  "Rare or endangered Canadian amphibians and reptiles."  The Canadian Field-Naturalist 84(1):9-16.
• Crother, B. I., J. Boundy, F. T. Burbrink, and J. A. Campbell. 2008. Squamata--snakes. Pp. 46-65. B. I. Crother (chair), and Committee on Standard English and Scientific Names (editors). Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth Edition. Society for the Study of Amphibians and Reptiles Herpetological Circular (37):1-84.
• David, S.M., K.M. Somers and R.A. Reid. 1994. Long-term trends in the relative abundance of crayfish from acid-sensitive softwater lakes in south-central Ontario: a data summary for the first five years, 1988-1992. Aquatic Science Section, Science and Technology Branch, Ontario Ministry of Environment and Energy, Dorset, ON 74pp.
• Davis, C. J. 2003. Impact of the Invasive Round Goby on Resident Crayfish Populations: An Examination of Potential Interactions, p. 28. In: Biology. Bowling Green State University, Bowling Green.
• Duellman, W.E. 1947.  "Herpetelogical records from Logan County, Ohio."  Copeia 3:208.
• Duellman, W.E. 1951.  "Notes on the reptiles and amphibians of Greene County, Ohio."  Ohio Journal of Science 51(6):335-341.
• Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada, Smithsonian Institution Press, Washington, D. C. 668 pp.
• Ernst, C. H. and R. W. Barbour. 1989. Snakes of Eastern North America. George Mason University Press. Fairfax, Virginia. Pages 141-142.
• Fletcher, Michelle and Scott Gillingwater.  Unpublished data, 1997.
• Francis, G.R. and C.A. Campbell.  1983.  "The herpetofauna of Waterloo Region, Ontario." Ontario Field Biologist 37(2):51-86.
• Froom, B. 1981. Ontario Snakes. Ontario Ministry of Natural Resources.  36 pp.
• Gallagher, L.  2003. Personal Communication to Scott Gillingwater, January 2003.
• Gartshore, M. E. and P. J. Carson. 1990. Queen Snakes and Spiny Softshell Turtles on the Thames River, Aylmer District. Report for the Ontario Ministry of Natural Resources.
• Gerry Waldron Consulting Ecologists. 2003. Revised Scoped Environmental Assessment for a Proposed Residential Subdivision, Part Farm Lots 34 & 35, Concession 1 (Former Anderdon Township) Town of Amherstburg, Ontario. March 19, 2003. Amherstburg, Ontario. Pg. 8
• Gibbons, J. W., and M. E. Dorcas. 2004. North American watersnakes: a natural history. University of Oklahoma Press, Norman. xxvi + 439 pp.
• Gillingwater, Scott.  Unpublished data 2002 – 2009.
• Gillingwater, S.D.  2002.  Reptiles at Risk, Queen Snake.  Fact sheet produced by the Upper Thames River Conservation Authority, London, ON.
• Gillingwater, S.D. 2008. National Recovery Strategy for the Queen Snake (Regina septemvittata) in Canada. Prepared for the Queen Snake Recovery Team.  Draft. 38 pp
• Gillingwater, S.D. 2009.  Spiny Softshell and Queen Snake Research and Recovery Along the Thames River Watershed.  Report submitted to the Ontario Ministry of Natural Resources.
• Gillingwater, S.D. and T.J. Piraino.  2002.  Rare Reptile Research of the Thames River Watershed.  Report submitted to the Ontario Ministry of Natural Resources, Aylmer District. 
• Greene, H.W.  1997.  Snakes: Evolution of Mystery in Nature.  University of California Press. Berkeley, Los Angeles, London.  351pp.
• Hall, R.J.  1969.  "Ecological observations on Graham's watersnake (Regina grahami Baird and Girard)."  The American Midland Naturalist 81(1): 156-163.
• Hamr, P. 1998. Conservation Status of Canadian Freshwater Crayfishes. Report to the World Wildlife Fund Canada and the Canadian Nature Federation.
• Hamr, P.  2004.  Personal Communication to Scott Gillingwater, July 2004.
• Harding, J.  1997.  Reptiles and Amphibians of the Great Lakes Basin.  University of Michigan Press.  Chicago, IL.
• Homyack, J. D. and W. M. Giuliano. 2002. "Effect of Streambank Fencing on Herpetofauna in Pasture Stream Zones." Wildlife Society Bulletin 30 (2): 361-369.
• Hulse, A. C., C. J. McCoy, and E. Censky. 2001. Amphibians and reptiles of Pennsylvania and the Northeast. Comstock Publishing Associates, Cornell University Press, Ithaca. 419 pp.
• Jacobs, D.  2003.  Personal Communication to Scott Gillingwater, June 2003.
• Jalava, J. 2009.  Hydro-riparian Species at Risk Inventory Bruce Peninsula National Park. Prepared for Parks Canada Agency  Bruce Peninsula National Park / Fathom Five National Marine Park
• Jones, Russ. pers. comm. 2009a. email correspondence to J. Kamstra  June 2009.  Naturalist at Ojibway Nature Reserve,
• Jones, Russ. pers. comm. 2009b. email correspondence to S. Gillingwater August 2009.  Naturalist at Ojibway Nature Reserve,
• Johnson, B. 1989. Familiar Amphibians and Reptiles of Ontario. Natural Heritage/Natural History Inc. Toronto. 168pp.
• Judd, W. W., 1955. "Observations on the Habitat and Food of the Queen Snake, Natrix septemvittata, at London, Ontario." The Canadian Field Naturalist 69 (4): 167-168.
• Judd, W. W. 1962. "Queen Snakes on the Ausable River at Arkona, Ontario." The Cardinal 41:2.
• Lamond, W. G. 1994. "The Reptiles and Amphibians of the Hamilton Area". The Hamilton Herpetofaunal Atlas. Hamilton Naturalists' Club. Pages 121-124.
• Layne, J. R. and N. B. Ford. 1983. "Flight Distance of the Queen Snake, Regina septemvittata."  Journal of Herpetology 18(4): 496-498.
• LeRay, W.J.  1928.  "The queen snake (Natrix septemvittata) in Ontario."  The Canadian Field Naturalist 42(2):42.
• Lesica, P. and F.W. Allendorf.  1995.  "When are peripheral populations valuable For conservation?"  Conservation Biology 9(4):  753-760.
• Logier, E.B.S.  1958.  The Snakes of Ontario.  University of Toronto Press, Toronto.  94 pp.
• Mackenzie, Stuart.  Pers. Comm. 2004 and 2007.  To S. Gillingwater.  Researcher, Bird Studies Canada.
• Mattison, C.  1995.  The Encyclopedia of Snakes.  Checkmark Books.  New York.
• Mattison, C.  1999.  Snake.  Firefly Publishing.  London.
• McBride, B. 1967. "Notes on Three Rare Ontario Snakes." Canadian Amphibian and Reptile Conservation Society 5 (6):1-4.
• Mills, R.C.  1948.  "A checklist of the reptiles and amphibians of Canada." Herpetelogica 4:1-15.
• Natural Heritage Information Centre (NHIC). 2010. Species Element Occurrence Report: Regina septemvittata. Website of the Natural Heritage Information Centre of the Ontario Ministry of Natural Resources. http://www.biodiversityexplorer.mnr.gov.on.ca/nhicWEB/main.jsp. Accessed DATE 2010.
• NatureServe. 2010. NatureServe Explorer: An online encyclopedia of life NatureServe, Arlington, Virginia. (Accessed: March 2010).
• Neill, W.T.  1948.  "Hibernation of amphibians and reptiles in Richmond County, Georgia."  Herpetologica 4:107-114.
• Niagara Area Ministry of Natural Resources.  Unpublished data 2003.
• Oldham, Michael.  Unpublished data from the Ontario Herpetofaunal Summary.
• Oldham, M.J.  1986.  "The queen snake: a reptile new to Essex County."  The Egret 3(3):25-26.
• Oldham, M.J. 1988. "Wanted: Queen Snake Sightings on the Thames River." The Cardinal 151:12-15.
• Oldham, M.J. and D.A. Sutherland.  1986.  Ontario Herpetofaunal Summary 1984.  Essex Region Conservation Authority and World Wildlife Fund Canada.  214 pp.
• Oldham, M.J., W.F. Weller.  1989.  Ontario Herpetofaunal Summary 1986.  Ontario Field Herpetologists.
• Joseph J. Parkos III, J., V.J. Santucci Jr., and D. Wahl.  2003.  Effects of adult common carp (Cyprinus carpio) on multiple trophic levels in shallow mesocosms.  Can. J. Fish. Aquat. Sci. 60(2): 182–192
• Piraino, T.J. and S.D. Gillingwater.  2003.  Biology and Ecology of Regina septemvittata Along the Upper Thames River Watershed.  Report submitted to the Upper Thames River Conservation Authority.
• Piraino, T.J. and S.D. Gillingwater.  2004.  Queen Snakes (Regina septemvittata) and Spiny Softshell Turtles (Apalone spinifera spinifera) Along the Upper Thames River Watershed.  Report submitted to the Upper Thames River Conservation Authority.
• Piraino, T.J. and S.D. Gillingwater.  2007.  The Queen Snake (Regina septemvittata) and Spiny Softshell Turtle (Apalone spinifera spinifera) along the Upper Thames River Watershed 2007.  Report submitted to the Upper Thames River Conservation Authority.
• Porchuk, B.D.  1996.  "Ecology and conservation of the endangered blue racer snake (Coluber constrictor foxii) on Pelee Island, Canada."  M.Sc. Thesis, University of Guelph, Ontario.  162 pp.
• Raney, E. C. and R. M. Roecker. 1947. "Food and Growth of Two Species of Watersnakes from Western New York." Copeia 3:171-174.
• Smith, K. 1999. COSEWIC Status Report on the Queen Snake (Regina septemvittata) in Canada.  Committee On the Status of Endangered Wildlife In Canada (COSEWIC) Status Report.
• Spurr, R. H. 1978. "The Queen of Hungry Hollow." Ontario Fish and Wildlife Review 17(1): 9-10.
• Spurr, R. H. and D. C. Smith. 1979. "Sightings of Queen Snakes (Regina septemvittata) Along the Ausable River near Arkona, Ontario."  Unpublished report.  10 pp.
• Stewart, D.  1974.  Canadian endangered species and habitats.  Gage Publishing Limited, Toronto.  172 pp.
• Stokes, G.D. and W.A. Dunson.  1982.  "Permeability and channel structure of reptilian skin."  American Journal of Physiology 242:F681-F689.
• Surface, H.A.  1906.  "The serpents of Pennsylvania."  Zool.  Bull., Div. Zool. Penna. State Dept. Agric., vol. IV, nos. 4 and 5.
• Tervo, Rob.  Personal Communication to S. Gillingwater.  March 2004 and 2006.
• Triplehorn, C.A.  1949.  "A large specimen and a high embryo count for the queen snake." Copeia 1:76.
• Vermeer, K.  1972.  "The crayfish, Orconectes virilis, as an indicator of mercury contamination."  The Canadian Field-Naturalist 86:123-125.
• Vlasman, K. 2004.  Personal communication, to S. Gillingwater.  March 2004.
• Vlasman, Kara. Unpublished data, 2005.
• Weller, W.  1983.  "Rare and endangered reptiles in Ontario-Part II." Canadian Amphibian and Reptile Conservation Society Bulletin 20(3):1-4.  January - February 1983.
• Wood, J.T.  1944.  "Fall aggregation of the queen snake."  Copeia 4:253.
• Wood, J. T. 1949. "Observations on Natrix Septemvittata (Say) in Southwestern Ontario." The American Midland Naturalist 42(3):744-750.
• Wood, J.T. and W.E. Duellman.  1947.  "Preliminary survey of Montgomery County, Ohio."  Herpetelogica 4:3-6.
• Wood, J.T. and W. E. Duellman. 1950. "Size and Scutellation in Natrix septemvittata (Say) in Southwestern Ohio." The American Midland Naturalist 43 (1):173-178.
• Woodliffe, Allen.  Personal Communication to S. Gillingwater September 2003.
• Wright, A.H., and A.A. Wright.  1957.  Handbook of Snakes of the United States and Canada.  Vol. 1.  Corness University Press, Ithaca, N.Y.