Fun Facts | thescooponsnakes

Fun Facts About Snakes

Here is some information about the snakes that we focus on in our project.

Eastern Ribbon Snake (Thamnophis sauritus)

Some Basic Facts

Semi-aquatic snakes found in marshes, wet meadows, scrub-shrub wetlands, and vegetated shorelines of ponds and lakes (Ernst and Ernst 2003).
Predominantly feed on amphibians and small fish (Bell et al 2007).

Rely heavily on blending in with the environment and hiding under cover to avoid predation (Scribner and Weatherhead 1995).
In Canada, they are found across southern Ontario and in some isolated areas in Nova Scotia.
May have multiple broods per female in a reproductive season (Langford et al 2011).
Recent habitat degradation and isolation as restricted distribution of these snakes alongside small population size has lead to the listing of the Atlantic

populations of Eastern Ribbon Snakes as "threatened" under the Species at Risk Act (SARA). Subsequently, this could potentially be the fate of Ontario populations in the future. (http://www.sararegistry.gc.ca/species/schedules_e.cfm?id=1)

Local Threats: (McNeil 2008; Smith 2002)

Lack of Information

According to COSEWIC the greatest threat to the Eastern Ribbon Snake is the lack of information on their natural history, ecology, population dynamics, and responses to changes in their environment.

Urbanization Disrupting Habitats

Habitat loss, fragmentation and degradation have decreased the availability and health of wetland and littoral habitats, decreasing movement and increasing competition for resources. Human activities leading to shoreline degradation have lead to wetland loss, while cottage and residential developments have also changed functional processes involving Eastern Ribbon Snakes, causing changes in movement patterns and genetic makeup of populations.

Other threats linked to urban expansion and land use include threats from agriculture and forestry changing habitats, as well as increased pollution, eutrophication and siltation of water having detrimental effects on many species of prey that Eastern Ribbon Snakes rely on. The development of roads also increases the chance for encounters of these snakes with humans and pets which may further affect their populations in and around the Great Lakes. In particular, Ribbon Snakes often travel between overwintering and summering sites across roads and are also drawn to bask and absorb heat from the sun near roads. This threat is significant in low traffic areas and increases in more developed areas.

Invasive Species

The introduction of exotic predatory fish into wetlands and the Great Lakes can and has altered trophic dynamics, causing dramatic reductions in small fish and amphibian populations. As temperatures rise, these exotic fish are expected to increase and thrive in the changing climate, better than native species, causing even more decreases in native fish and amphibians (Vander Zanden et al 2004). A decrease in prey abundance increases competition between Eastern Ribbon Snake individuals and can cause declines in their population.
In addition, more Ribbon Snakes are being killed by domestic pets brought to these environments through cottage and residential developments.

Changes to Water Level

Dam construction by beavers and humans have culminated in long-term habitat disruptions and altered the access that these snakes have to freshwater and the access that their prey have to freshwater. Other factors such as changes to shorelines, climate change, flooding, and droughts can also change the water levels, impacting snake populations.

Climate Change

Climate changes can have a variety of effects on Eastern Ribbon Snake populations including changing water flows and levels, temperature, precipitation, and habitat availability for snakes and their prey. These changes may also affect the development of young snakes. Climate change may cause the temperatures of Ribbon Snake habitats to decrease, resulting in increased freezing and dehydration of individuals.

Finally, all of these threats to Ribbon Snake populations can and have lead to increasingly smaller populations that are isolated from other populations by roads and other habitat disruptions. Smaller populations of individuals experience increased vulnerability to inbreeding depression, genetic drift, and stochastic events, causing increased mortality and decreased fecundity (i.e. potential for successful reproduction).

Eastern Milksnake (Lampropeltis triangulum)

Some Basic Facts (http://www.sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=714)

They are shiny, slender, and large snakes usually between 60-90cm in length.
They have smooth scales that are usually tan, brown or grey and blotches that are usually brown, copper, or red.
Often, they also have a white belly with a "Y" or "V"- shaped light coloured patch on the back of their neck.
In Ontario, Eastern Milksnakes can be found as far north as Lake Nippissing and found in all areas with suitable habitat around the Great Lakes and are plentiful in areas with and abundance of small animals (shrews, mice, moles).
Few Eastern Milksnakes are found in areas with high levels of Eastern Racer Snakes (competitor and predator) as well as raccoons, foxes, skunks, and weasels which are some of their natural predators.

Generally can be found in rural areas in and around buildings but are also found in forests, rocky hillsides, pastures, prairies - pretty much anywhere close to water and in areas suitable for basking and egg laying.
Name comes from the belief that snakes would enter barns and steal milk from cows, which is completely untrue.
They are considered constrictors that suffocate their prey before consuming them.
Feed on rodents in large numbers and spend a lot of time hiding.

In the spring and fall they are active at dawn and dusk, while in the summer they are diurnal.
They usually go into hibernation in late October and early November and emerge in April or May.
Eastern Milksnakes are often mistaken fo other snakes including the black rat snake, water snakes, Eastern and Western foxsnakes, and juvenile racer snakes.
The Eastern Milksnake has been listed as a "species of special concern" on the Species at Risk Act since 2002 (http://www.sararegistry.gc.ca/spcies/schedules_e.cfm?id=1).

Local Threats COSEWIC 2002

Road Mortality

Similar to most other reptile and amphibian species, many deaths of Eastern Milksnake individuals have been caused by being run over by vehicles both on and off the road. More specifically, according to studies done by Lamond in 1994 and the Ontario Natural Heritage Information Centre in 1997, 16% of all Milksnakes found dead in Ontario are killed by vehicles on the road and in the Hamilton, Ontario area alone, this number rises to 27%. These numbers have potentially increased substantially since the time of these studies due to increasing urbanization, road development, and traffic.

Deliberate Persecution

Eastern Milksnakes are generally large snakes and may frequently be found in basements, leading to deliberate killing by humans when sighted. Moreover, Milksnakes, which are non-venomous, may appear to act like venomous species and be aggressive when frightened, causing people to fear and kill them.

Habitat Loss and Modification

Decreasing field sizes and forest/marsh cover due to further development and human encroachment on the natural habitats of Milksnakes has lead to declines in their abundance.
Many old buildings and barns around Kingston from the early settlement ages where Milksnakes often like to live have been abandoned and are being removed to allow for further urban development.
Many abandoned fields are also being reverted back to forests, affecting the amount of prey available to Milksnakes because agricultural areas support many rodent populations.

Massive Collecting

Eastern Milksnakes have become increasingly vulnerable to unsustainable collecting as they can be viewed as very desirable pets in certain countries and areas, bringing around $25-$35 each, meanwhile over time this may cause significant declines in wild Milksnake populations.
The hunting and poaching of snakes for pets is projected to increase in areas with increasing human populations (Hussey and Goulin 1990).

Black Rat Snake (Elaphe obsoleta)

Some Basic Facts

Is the largest snake in Canada, and can be up to 8 feet in length. Some have reported them to be up to 9 feet as well (Infoqis Publishing Co. 2009).
Completely black except for a white chin and throat. Hatchlings are pale grey with black splotches along the back, and will become darker as it matures (Aminal Diversity Web 2011).
When approached by a predator, they will coil their bodies and rattle their tails. They will also release a foul-smelling musk on the predator if they are picked up (Animal Diversity Web 2011).
The juveniles' diet consists of lizards, baby mice, and frogs. The adults mainly eat rats and mice, but they also eat chipmunks, moles, birds eggs and young (Animal Diversity Web 2011).

Kills its prey through constriction (Animal Diversity Web 2011).
These snakes lay around 12-20 eggs, usually in hidden areas under hollow logs of leaves, or in abandoned burrows (Animal Diversity Web 2011).
These snakes are fantastic climbers, as well as swimmers (Infoqis Publishing Co. 2009).
Small populations are found in North America (The Frontenac Axis and eastern Ontario and in the Carolinian Forest of southwestern Ontario) and New York, and larger populations are found in Texas and Nebraska. They prefer heavily wooded areas, but are found to do well in trees, water, flat farmland, rocky regions, and regions of high elevations (Infoqis Publishing Co. 2009).
They are listed as a "threatened" species in Canada.

Local Threats

Persecution and Harassment by Humans

Black Rat Snakes tend to be feared by many people because of their large size. People intentionally kill these species for 'fun' by running them over with cars or lawnmowers, and some people even shoot them.
Humans or their pets also harass these snakes by disturbing their nests or basking areas. They may remove vital habitat that the snakes need, such as basking rocks, because they wish to get rid of the snakes. The snakes are not harming anyone, but the unfair persecution they face seems to have convinced people that they are dangerous.

Harassment and Predation by Household Pets

Large dogs are capable of killing or harming adult Black Rat Snakes. Both cats and dogs are capable of harming juvenile snakes as well. Keeping your pets away from snakes can help ensure the safety of this species. You can also make your property 'snake proof' in a positive way, so that your pets are less likely to encounter these snakes. Check out the 'Get Involved' page for more details on how to 'snake proof' your home.

Habitat Loss and Fragmentation

Habitat fragmentation and loss is the main problem for these species, as it is for many others. But identifying these habitats, through thorough research, may help to amend this problem.
The identification and protection of traditional/communal hibernacula of Black Rat Snakes is importatant for the conservation of this species, and the assessment of hibernacula availability can help determine how much population distributions are limited by habitat suitability (Prior and Weatherhead 1996).
Hibernacula that has been identified, however, has been abused by some people. For example, some people participate in 'snake round-ups', and these events have caused serious decline and extirpation of populations in parts of the USA.
Prior and Weatherhead (1996) conducted a study that quantified the variability in Black Rat Snake hibernacula. They studied 10 hibernacula located at Murphy's Point, QUBS, Charleston Lake Provincial Park, La Rue Mills, and Hill Island.
They found that hibernacula, in general, seemed to be situated on moderately sloping and relatively rocky hillsides. However, they did discover that Black Rat Snake hibernacula cannot be found based on a few characteristics, and that radiotelemetry is the best method to use to find these hibernacula sites (Prior and Weatherhead 1996).
They also found that snakes prefered large, partially dead and/or hollow trees instead of younger, healthier trees. This suggests that Black Rat Snakes select specific attributes or 'tree class' for basking around their hibernacula (Prior and Weatherhead 1996).
This information may help decrease the threat of habitat loss and fragmentation to these snakes because studying their behaviours and preference in habitats can indicate what needs to be conserved, how much needs to be conserved, etc. Habitat fragmentation and loss is a real threat, and it is vital that we know what this species requires to ensure its continuity. Tradition and communal hibernacula generally need structural stability, it needs to be deep enough so snakes do not reach fatal temperatures, and it must be sufficiently humid for surviving the winter (Prior and Wheatherhead 1996).
Another similar study by Weatherhead and Charland (1985) focused on habitat selection of Ontario populations of Black Rat Snakes at the QUBS station. The goal was to locate the habitats selected by the snakes, as there is a lack of information in this field because of the secretive

nature of snakes. Also, sightings of these snakes are quite biased because people assume that where they are visible determines what habitat they like best, but this may not be the case.

Weatherhead and Charland (1985) found a strong association of Black Rat Snakes with edge habitat. They linked this behaviour with bird breeding seasons, which reflected the diverse prey items these snakes eat, such as ruffed grouse, American robin, eastern phoebe, and yellow warbler (Weatherhead and Charland 1985). They hypothesized that the prefered habitat of Black Rat Snakes is a mosaic field and woodlot, with the mosaic occuring on a small scale (Weatherhead and Charland 1985).
Again, this study highlights the potential areas that may need to be conserved

for the survival of these species. More research needs to be done to get an idea of what habitats we should be avoiding for urbanization.

Traffic Mortality

Roads can affect the surrounding environment in many ways that are detrimental to neighbouring animal populations, such as mammals, reptiles, and invertebrates (Row et al 2007). Therefore they act as barriers to gene flow and can reduce the overall genetic diversity of populations, leading to and increased risk of extinction. Roads cause heavy mortality in snakes and can alter populations, depending on which sex of the species is dying from the roads (Row et al 2007). For instance, mortality rates of reproductive females will have a greater effect on the population than non-reproductive females (Row et al 2007).
A study by Row et al (2007) at QUBS focused on the impacts of secondary roads on a population of Black Rat Snakes. This population is vulnerable because it takes these snakes 7-9 years to reach maturity, and they have a max lifespan of 20 years (Row et al 2007). Their study showed that Black Rat Snakes did not avoid crossing roads, and that larger snakes were less likely to avoid roads. Males and reproductive females crossed roads more during the mating and nesting seasons (Row et al 2007).
Row et al (2007) counted the number of snakes killed on the road, but this is still an underestimated value, as some of the snakes may have been taken by scavengers, or the snakes may have crawled off the road to die elsewhere (Row et al 2007). They did determine that if as little as 3 adult females are killed per year, this population can have an increase in the probability of extinction of up to 90% (Row et al 2007).
One thing to keep in mind with this experiment is that it was performed in an area with low traffic. Any populations outside of this area, that are more heavily human-occupied, may be at a higher risk, as there is a higher chance of road mortality for these snakes.
A study by Boulin-Demers and Weatherhead (2002) focused on gene flow in Black Rat Snakes. As the habitat becomes more fragmented, populations become smaller and isolated, and this can put them at risk of inbreeding depression and genetic drift, as gene flow will be blocked. The goal of their study was to evaluate the implications of movement patterns for gene flow between the hibernacula of Black Rat Snakes (Boulin-Demers and Weatherhead 2002).
Boulin-Demers and Weatherhead (2002) determined that reproductive females were farther from their hibernacula than males were, and males moreso than the non-reproductive females. Females nested far from their hibernacula to increase the chance of their offspring to join other hibernaculas (Boulin-Demers and Weatherhead 2002). This suggests that, to maintain the genetic integrity of Black Rat Snakes, it will require the preservation of a sufficient buffer of suitable habitat around hibernacula to allow snakes to interact during the mating season (Boulin-Demers and Weatherhead 2002). This supports the notion that roads can divide the environment, reduce interactions, and thus increase mortality in these species.
Finally, a study by Prior et al (1996) further supports the idea that road mortality is an issue for Black Rat Snakes. The focus of their experiment was to assess the genetic structure and levels of gene flow in Black Rat Snakes on different scales, and to characterize the genetic diversity of remnant populations found in Ontario.
In short, they found that habitat heterogeneity, fragmentation, aspects of the snakes' behavioural ecology, patterns of human activity, and geographic distance all contribute to an interference in the rate of gene flow among sub-populations, that are about 25-35 km apart (Prior et al 1996).
They determined that, because some hibernacula exist in urban landscapes (like multi-lane highways, residential subdivisions), snake movement may be restricted, and decrease the chances of hibernacula interactions. This implies that gene flow among Black Rat Snake populations can be easily disrupted.