Did you know that some snakes are threatened and endangered in Ontario?

(Photo source: http://www.atomica.com/article/1334099/20-photos-that-prove-snakes-are-fab-when-wearing-hats?s=5)

The first impression that comes across your mind when you see a snake lying on the highway is probably one of the following:

1. “Oh my goodness!”
2. “Ew.”
3. “Just run it over, no big deal!”
4. All of the above

However, have you ever imagined a world without snakes, if we kill them all?

In our ecosystems, snakes are one of the most important components of the mid-order predators. Without snakes, the number of prey species, including rodents, harmful bugs, and insects, would increase to unnatural extents. This would in turn lead to severe reduction in crop production because of the disappearing of the natural pest control, snakes! Also, the higher order predators (some birds, and other bigger snakes) who prey on snakes would be having difficulties hunting because of the lower food abundance.

What exactly have we done to the global snakes population?

(Photo source: http://www.quickmeme.com/meme/3ul2r8)

The global snake and reptile populations have been shown to demonstrate similar declining patterns (Reading et al. 2010; Whitfield Gibbons et al. 2000). These studies suggested snake populations need our attention because for some of them, human activities have been the cause of declines. Currently in Ontario, there are 9 snakes species listed as threatened or endangered in the Species at Risk list (Environmental Canada 2015). With timber rattlesnakes being extirpated in Ontario, it is critical and urgent that we take actions to protect snakes in Ontario. You are probably thinking “I have never killed/run over a single snake”.

But here is a list of anthropogenic activities that could potentially affect the snakes populations:

• Rural development → Habitat destruction/loss

• Road construction → habitat fragmentation

• Intentional/Unintentional Roadkill
• Negative impression of snakes
• Water pollution → Decrease food availability
• Consumption of snakes
• Climate change
• Small populations

References:

C. J. Reading, L. M. Luiselli, G. C. Akani, X. Bonnet, G. Amori, J. M. Ballouard, E. Filippi, G. Naulleau, D. Pearson and L. Rugiero. (2010). Are snake populations in widespread decline? Biology Letters doi:10.1098.

Environmental Canada. (2015). Species at risk list in Ontario.  
https://www.ontario.ca/environment-and-energy/species-risk-ontario-list

Whitfield Gibbons, J., D. E. Scott., T. J. Ryan., K. A. Buhlmann., T. D. Tuberville., B. S. Metts., J. L. Greene., T. Mills., Y. Leiden., S. Poppy., and C. T. Winne. (2000). The Global Decline of Reptiles, Déjà Vu Amphibians. Bioscience 50(8): 653-666.

The importance of “unattractive” snakes

Conservation efforts are generally targeted towards “attractive” animals because the general public is more concerned with “cute” animals going extinct. These flagship species are generally large mammals used as an icon of conservation organizations, and are considered to be charismatic to the general public. Research studies have revealed that the majority of conservation fundraising and research focusses on flagship species, mainly large mammal species; whereas, little to no attention was given to the non-flagship reptiles and amphibians (Joseph et al. 2011; Smith et al. 2012). This means that the vast majority of the public are more willing to donate money to save the endangered pandas, but no one really cares about snakes. 
Unfortunately, flagship species only represent a small portion of all the currently listed endangered species (Joseph et al. 2011; Smith et al. 2012). Oftentimes, conservation efforts made on non-flagship species rely on flagship species fundings; however, Benett et al. (2015) found that this allocated funding was small and inefficient for most non-flagship species.

(Photo source: http://www.wall-pix.net/entertainment-cartoons-comics/00005083.jpg.html)

In Ontario snakes are considered unappealing due to misconceptions that they are dangerous, even venomous. At the same time a number of Ontario snake species are at risk, with many falling onto threatened or endangered species lists (Environmental Canada 2015). Unfortunately, Ontario residents are generally uninformed and unwilling to help in the conservation of these species due to their aversion to snakes. This can sometimes compound the threats facing snakes in Ontario, for example in the instance of (intentional) road kill. In a Harris Poll conducted by Taylor (1999), ophidiophobia, the abnormal fear of snakes, was reported to be the most common fear shown in adults. Perhaps this fear of snakes has led to the status and crisis of snakes species.

As mentioned in Did you know that some snakes are threatened and endangered in Ontario?, snakes are actually of huge importance in our ecosystems. Snakes and many other non-flagship species also need public attention in conservation. Unfortunately, most of the time we are unaware of the fact that our daily actions could potentially threaten these endangered species.

Importance of conserving and studying snakes

Apart from the important roles snakes play in our ecosystem, scientists study snakes for various reasons in hope to accentuate the many positive aspects of snake biology. Snakes are a common model organism for studying the ecological effects of human infrastructure, such as road mortality (e.g. Shepard et al. 2008; Garrah et al. 2015), and habitat fragmentation (e.g. Robson and Blouin-Demers, 2013). These results contributed to our understanding of snakes habitat preference and their energetic adaptation to human-induced changes.

Snakes are also studied as an indicator species of the health of terrestrial ecosystem (Lillywhite 2010). Snakes are commonly used indicators of environmental contamination and pollution by pesticides, herbicides, insecticides residues (e.g. Stafford et al. 1976; Burger et al. 2004; Burger et al. 2007). Bioindicators exhibit changes in response to different stressors in the environment and the effects are relatively easy to measure for scientists. Long-lived snakes serve as a great bioindicator because they are top predators and show varied levels of accumulation of metal contaminants in blood, muscle, liver and skin (Burger et al. 2004; Burger et al. 2007).

Ectothermic snakes are also widely utilized to assess the effect of climate change on reptiles and amphibians. Even though certain degrees of plasticity were shown in young snakes adjusting their thermoregulatory behaviour, decreased fitness including decreased growth rate in cold-raised young, less locomotion, and less anti-predator responses were observed due to the lack of thermal plasticity in elder snakes (Aubret and Shine 2009). This study suggested that climate change would significantly affect the mean selected body temperatures because of a mismatch between thermoregulatory tactics and the ambient temperature (Aubret and Shine 2009). More on this: Climate change and potential threats on snakes.

References:

  

Aubret, F., and R. Shine. (2009). Thermal plasticity in young snakes: how will climate change affect the thermoregulatory tactics of ectotherms? The Journal of Experimental Biology 213: 242-248.

Burger, J., K. R. Campbell., T. S. Campbell., T. Shukla., C. Jeitner., and M. Gochfeld. (2004). Use of skin and blood as nonlethal indicators of heavy metal contamination in northern water snakes (Nerodia sipedon). Arch. Environ. Contam. Toxicol. 49: 232-238.

Burger, J., K. R. Campbell., S. Murray., T. S. Campbell., K. F. Gaines., C. Jeitner., T. Shukla., S. Burke., M. Gochfeld. (2007). Metal levels in blood, muscle and liver of water snakes (Nerodia spp.) from New Jersey, Tennessee and South Carolina. Science of the Total Environment 373: 556-563.

Environmental Canada. (2015). Species at risk list in Ontario.

https://www.ontario.ca/environment-and-energy/species-risk-ontario-list

Joseph, L. N., Maloney, R. F., Watson, J. E.M. and Possingham, H. P. (2011). Securing nonflagship species from extinction. Conservation Letters, 4: 324–325.

Lillywhite, H. B. (2010). Focus on snake conservation. Snakes: Ecology and Conservation. Bioscience 40(4): 315-317.

Smith, R.J., Verissimo, D., Isaac, N.J.B., & Jones, K.E. (2012). Identifying Cinderella species: Uncovering mammals with conservation flagship appeal. Conservation Letters 5: 205-212.

Taylor, H. (1999). What we are afraid of. The Harris Poll #49, August 18.

http://media.theharrispoll.com/documents/Harris-Interactive-Poll-Research-WHAT-WE-ARE-AFRAID-OF-1999-08.pdf

Robson, L. E., and G. Blouin-Demers. (2013). Eastern Hognose Snakes (Herodon platirhinos) avoid crossing paved roads, but not unpaved roads. Copeia 3: 507-511.

Correcting Misconceptions – Ontario Snakes are NOT Dangerous

            Despite popular belief, the snake species that inhabit Ontario are not dangerous. People often imagine snakes as aggressive, venomous animals that will go out of their way to harm humans. However, this perception of snakes is wildly incorrect. In reality, Ontario snakes tend to be docile and will avoid attacking a perceived threat (like humans) at all costs, if they attack at all. Even in the event of aggressive snake behaviour keep in mind that all Ontario snake species are non-venomous, with the exception of the eastern massasauga (Government of Ontario, “Massasauga Rattlesnake” 2015). Even in the case of the eastern massasauga though you do not need to be afraid.

Eastern Massasauga

The eastern massasauga, also known as the massasauga rattlesnake, is Ontario’s only venomous snake and the last remaining rattlesnake species in the province (Crowley, “Eastern Massasauga” 2015). Despite this, the eastern massasauga is not a threat to humans.

First of all, the eastern massasauga is very rare in Ontario and the chances of encountering this species are very low (Government of Ontario, “Massasauga Rattlesnake” 2015). Like most Ontario snake species the eastern massasauga is shy and non-aggressive in nature (Rowell, 2012). In the face of a threat, this species most often attempts to hide or retreat, not attack (Government of Ontario, “Massasauga Rattlesnake” 2015). In fact, research shows that even when approached eastern massasauga snakes tend to remain motionless, meaning you could closely pass by an individual and be none the wiser (Crowley, “Eastern Massasauga” 2015). If escape is not an option or a threat persists the nest step of defense for the eastern massasauga is to rattle its tail as a warning, but it will still resist attacking a predator (Government of Ontario, “Massasauga Rattlesnake” 2015).

Only as a very last resort will a massasauga snake attempt to strike and bite, and this species can only strike over a relatively small distance of about 30 cm (Crowley, “Eastern Massasauga” 2015). In the very unlikely event that you are bitten by an eastern massasauga there is still little likelihood of severe consequences, as long as proper follow up is carried out. In Ontario there have only been two deaths caused by a massasauga bite, both of which occurred over 50 years ago because proper medical attention was not sought out (Government of Ontario, “Massasauga Rattlesnake” 2015). In response to a bite from this species stay calm and immediately seek out medical care (Government of Ontario, “Massasauga Rattlesnake” 2015).

Negative connotations of the eastern massasauga, derived from it being venomous, carry over to other snake species even though they are (also) not dangerous. Consider for example the eastern hog-nosed snake, gray ratsnake and queensnake.

Eastern Hog-Nosed Snake

The aggressive defensive behaviors of the eastern hog-nosed snake. Photo Credit: Joe Crowley (Crowley, “Eastern Hog-Nosed Snake” 2015).

Perhaps one of the most misunderstood snake species in terms of perceived danger is the eastern hog-nosed snake, as a result of its defense strategies. When faced with a threat, eastern hog-nosed snakes often first attempt to flee, although if escape is unsuccessful the species can put on an impressive, and frightening, cobra-like display (Rowell, 2012). To scare away predators these snakes will take on a cobra-like stance of a raised head and neck, hiss loudly, and make mock strikes (with a closed mouth)  (Government of Ontario, “Eastern Hog-Nosed Snake” 2015). If all else fails the final defense strategy of eastern hog-nosed snakes is to play dead (Government of Ontario, “Eastern Hog-Nosed Snake” 2015). Remember that, while their defense strategy is very intimidating, eastern hog-nosed snakes are harmless and non-venomous.

I stress that hog-nosed snakes are non venomous because, while their saliva does contain mild toxins, it is not dangerous to humans (Rowell, 2012). The mild toxins produced by this species are not consider venom in the traditional definition of the term, as they can do not quickly kill prey (Rowell, 2012). Hog-nosed snakes cannot bite and inject these toxins into humans unless they are held for a long period of time, and even then, the toxins are not harmful to humans (Crowley, “Eastern Hog-Nosed Snake” 2015). It is important to note that hog-nosed snakes are very reluctant to bite any predator, and despite their frightening defense displays have a quite tame nature.

Gray Ratsnake

Although the gray ratsnake is harmless many individuals are scared of this species because of its large size (up to 2m!) and defense behaviors (Government of Ontario, “Gray Ratsnake” 2015). Most often when approached by a predator the gray ratsnake will freeze to avoid detection, but in some cases it will mimic the defence behaviors of the eastern massasauga by quickly vibrating its tail against the ground to make a warning rattle sound (Rowell, 2012). Thus, if you observe rattlesnake-like behavior it is important to remember that Ontario’s only rattlesnake is quite rare and other snake species that are non-venomous (e.g. the gray ratsnake) have similar defense behaviors, so you are very likely not in danger.

Queensnake

The queensnake is a shy and incredibly harmless snake species. Queensnakes are non-venomous and when threatened will always attempt to flee (Rowell, 2012). Even when humans handle them, very rarely do queensnakes bite but instead tend to squirm and release a fowl odor in attempts of being released (Rowell, 2012).

Like any animal snakes exhibit defensive behaviour in the presence of a threat, such as a human which is much larger than itself. Always keep in mind that, while these defense behaviors can be intimidating, all snake species in Ontario are harmless to humans. Of course, knowing that Ontario snakes are not dangerous does not mean you won’t be scared if you see one in the wild, but know that as long as you do not engage with a snake that is displaying aggressive defense behaviour you are not threatened in any way.

References:

Crowley, J. (2015). Eastern Hog-Nosed Snake. Ontario Nature. http://www.ontarionature.org/protect/species/reptiles_and_amphibians/eastern_hog-nosed_snake.php.

Crowley, J. (2015). Eastern Massasauga. Ontario Nature. http://www.ontarionature.org/protect/species/reptiles_and_amphibians/eastern_massasauga.php.

Government of Ontario. (2015). Massasauga Rattlesnake. http://www.ontario.ca/page/massasauga-rattlesnake.

Government of Ontario. (2015). Eastern Hog-Nosed Snake. http://www.ontario.ca/page/eastern-hog-nosed-snake.

Government of Ontario. (2015). Gray Ratsnake. http://www.ontario.ca/page/gray-ratsnake.

Rowell, J. (2012). The Snakes of Ontario: Natural History, Distribution and Status. Toronto, ON.