Welcome fellow salamander enthusiasts!
Some of you may already be familiar with our Twitter page (@MacSalamanders), if not, we are a group of four undergraduate students from McGill University (Montreal, QC) conducting a research project on salamanders. Salamanders and newts are amphibians within the Caudata order and belong to the Salamandridae family and Pleurodelinae subfamily, respectively . Similar to frogs and lizards, salamanders have smooth and moist skin, however, newts have warty and dry skin; these characteristics are indicative of habitat and lifestyle . Additionally, these vertebrates possess the ability, even in adulthood, to regenerate severed or shed limbs; this defense mechanism proves to be extremely useful against predators .
Indigenous to our data collecting zone (Morgan Arboretum, Sainte-Anne-de-Bellevue, QC), the blue-spotted salamander (Ambystoma laterale) , the red-backed salamander (Plethodon cinereus)  and the red-spotted newt (Notophthalmus viridescens)  are our project’s study species. Blue-spotted salamanders are nocturnal creatures which breed in swamps and ponds during the spring allowing the eggs to be laid in water . The red-backed salamanders, existing in two color phases (lead back or red/orange-striped back), typically breed in the fall and females lay their eggs on rotten logs . The red-spotted newts breed in the water following extensive courtship displays. Interestingly, their skin contains toxins which have proven lethal to most of their predators . Lastly, these salamanders are cold-blooded and must hibernate in order to survive during the colder seasons .
Habitat and Distribution
Salamanders can be found underneath rocks or logs in their terrestrial stage or at the bottom of streams or ponds in their aquatic stage . The blue-spotted and red-back salamanders are only terrestrial so they can be found under rocks or logs whereas the red-spotted newt lays its eggs in their aquatic stage so they can be found at the bottom of streams or ponds as well as rocks and logs .
There are 21 species of salamanders located in Canada and 10 of those can be found in Quebec. A few factors that affect the distribution of salamanders are habitat modification and climate change. As a result, the amphibians of Canada suffer greatly from decreased precipitation and elevated temperatures during the summer .
Video: Red-backed salamander found beneath a rock from one of our data collection zones
Red-backed salamanders hunt large and nutritious arthropods like millipedes, fly larvae, beetle larvae, and spiders . They do so by thrusting their tongues quickly to entrap prey and then bring it in their mouths. Since salamanders do not like dry conditions, they will hunt more actively after a rainfall or in conditions of high humidity. When the environment dries out, they will retreat back under logs and rocks in order to stay moist. Salamanders eat as much as they can in favorable conditions and store the extra food as fat which is burned when the salamanders catch less prey, allowing them to survive in more scarce conditions .
Importance to Ecosystems
The salamander is important in monitoring the wellbeing of an ecosystem. Because of their sensitivity to ecological changes, tracking the salamander population over time allows us to observe many other important factors of ecosystem wellbeing. This includes moisture cycling, the dynamics of the foodweb, succession, and general biodiversity. Because of their abundance and the relative ease at which they can be found, the salamander is often considered somewhat of a “canary in a coal mine”, and for this reason have much importance in their ecosystem .
Research question – What environmental parameters (forest type, soil temperature, and preferred coverage) can be associated with the highest density of salamanders in the Morgan Arboretum?
For our research project, we sampled areas within deciduous forests, coniferous forests, and mixed forests. We set up 10 meter by 10 meter quadrants where we would collect all our data. We sampled each quadrant by starting in one corner of the collecting zone and moving outwards flipping over rocks and logs within that area searching for salamanders.
Part way through our data collection, we began to sample differently since in some quadrants 0 salamanders were found compared to other areas where we found close to 20. To ensure we could collect data, we would first look under rocks and logs until we found a salamander. Once we discovered a salamander, we set up our collecting zone around it. This guaranteed a minimum of 1 salamander per quadrant.
Over the course of our data collection period, we encountered several obstacles we had to work around in order to ensure the accuracy of our data. Our first hurdle occurred as we first ventured into the Morgan Arboretum: we hadn’t anticipated for the ground to be so covered with fallen leaves and other organic matter. As a result, it was much more difficult to locate salamanders as opposed to just a few weeks prior, when all the leaves were still on the trees. We adjusted our methods to include a “sweeping” step, where we temporarily cleared the leaf cover off the areas we were sampling to ensure that no rock or log went unturned.
We soon found that without a proper protocol in place, it was possible for different team members to find the same salamander at different times, but count it as two separate specimens. To prevent overcounting, we established a system where whenever one team member found a salamander, we would all converge to record data and take note of where exactly it was found. We also took photos of each salamander and where it was found for our own reference.
Another challenge we faced was that we were sometimes not physically strong enough to flip over a large log or a rock. This created the possibility of undercounting the population, as it was still possible for salamanders to be hiding under these bigger objects. Unfortunately, we had no way of countering this obstacle with our equipment at hand. Instead, we will keep this in mind when we complete our data analysis, and evaluate how this could affect our final result.
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