The Art of Catching Salamanders in Ten Steps
A new school year has begun. The calm, empty campus that I had grown accustomed to over the summer while working in the herpetology lab is now infested with eager as well as not-so-eager young minds. I feel rather strange when I think about this being my last year of undergraduate studies. I will miss the beautiful scenery and the lovely atmosphere cultivated by the dozens of wonderful people that I have befriended in this town. That being said, I am also terribly excited about the idea of discovering a new city and campus. Already, I can feel my blood thicken with the urge to explore and relocate.
Classes started on Thursday and I am happy to report that not only am I genuinely interested in the content of all the courses I am taking this semester, but my professors also all seem to enjoy teaching and interacting with students. This is an auspicious start to the fall semester.
On Saturday morning, I met my thesis advisor at the lab so we could prepare for a day of salamander collecting. The plan was to release the 110 salamanders that we had caught in early May as well as to catch the 90 new salamanders needed for my experiment.
We set out with the goal of catching 80 males and 10 females because my research will largely focus on male salamanders. This was my second foray into the world of salamander collecting, and so, I present to you the valuable knowledge I have gained during these two expeditions.
1. During the summer months, pick the warmest day of a week where heavy rainfall occurred.
The Red Backed salamander borrows deep into the soil in the winter months and is virtually uncatchable at that time.
2. Find a conservation area you can easily access.
3. STOP- Makes sure you have the proper permits!
In our case, three separate permits were required to catch and transport these salamanders out of Rockwood conservation area, Ontario.
4. Find a forested area away from campsites, beaches and roads.
Red Backed salamanders avoid humans and roads because of the disturbances they cause in the environment as well as the vibrations resulting from loud noises.
5. Once in the forest, seek out areas where there is lots of tree cover protecting the soil from direct sunlight.
Salamanders are amphibians and although Plethodon cinereus does not spend any part of its life cycle in an aquatic environment, it still requires lots of humidity in order to survive. Moisture enables this lung-less and gill-less animal to breathe through its skin (cutaneous respiration) and is essential to maintaining internal balance.
6. In the shaded area, look under rocks, logs and leaf litter.
The Red Backed salamander is a nocturnal animal. It becomes active at night and only then will it come out and actively hunt its prey. Trouble is, at night they are much harder to see. You must therefore look for them in areas where they might be hiding, such as under rocks and logs.
You might catch a salamander having a light snack during the daytime, but, in this case, the prey is caught using an ambush predation strategy. This means that the salamander will simply sit and wait for the next potential meal to come along.
What do these salamanders eat, you might ask? Well, in the lab we feed them live crickets that we raise ourselves. We feed them young crickets because they are smaller than their adult counterparts and therefore more easily ingested. In the wild, however, they eat a variety of small arthropods. This includes mites, insects and their larvae, and spiders. They will also eat slugs and earthworms. salamanders thrust their tongue out in a quick, forward motion in order to catch their prey.
7. Act quickly!
A startled Red Back will try to wiggle away or bury itself as soon as you lift the rock or the log that was covering it. We always miss a few because they are simply too fast for us.
8. Don’t grab them by their tails!
If you do this, you might find yourself with a wiggling salamander tail devoid of an actual salamander!
Salamanders have a nifty little predator avoidance strategy called “autotomy”. They can autotomize their tails, a self-amputation act, when they feel threatened. Not only does this allow them to get away when a predator catches them by the tail, but, because the tail continues to jerk once it is discarded, this adaptation can also be used to distract a predator from attacking the arguably more important and meaty salamander body.
A salamander that survives a predatory attack will grow a new tail. This is called regeneration. Given enough time, the new tail will be just as long as the previous one, albeit slightly discoloured.
Red Backs have numerous predators. These range from small garter snakes to birds and shrews. However, under utopian conditions in which they would never encounter such threatening creatures, they can live up to 10 years.
9. Place them in a plastic bag with humid paper towels until you are ready to put them in a cooler with ice for transport.
Remember, humidity is important!
Otherwise you will end up with dried out dead salamanders.
10. Load the cooler into the car and bring them back to your lab where you place them individually in plastic containers such as these:
In the end, we managed to trap 113 salamanders in 5 hours. We had had a lot more luck in May and, unfortunately, as we approach winter, these salamanders will be harder and harder to trap.
I was hoping to be able to sex all the salamanders on site, but the equipment we brought was not suitable for such a task. You see, in order to determine the sex of a salamander, one must have 2 very simple things: a very bright light and a humid plastic bag.
The salamander is placed in the plastic bag and immobilised using one’s fingertips. One must then hold the salamander up the to light to view the abdominal contents. A male will have testes on either side abdomen that show up as small dark elongated disks. A female will have no visible testes, but may be endowed with small eggs instead. This technique is called “candling” and is described in a journal article written by Gillette and Peterson, 2001.
We had brought a flashlight in order to sex the Red Backs but, given the outdoor lighting conditions, the flashlight’s rays were not sufficiently strong to pierce through the freshly caught critters. We decided to bring the salamanders back to the lab, where I spent the following three hours determining their sex. I identified 43 males, 57 females and 13 juveniles that were too young to sex accurately. We did not, in true Pokemon style, manage to “catch em’ all”.We will have to return to Rockwood next weekend to get some more males and return the excess females that I will not be using in my experiment.
Despite not reaching our goal, I enjoyed myself immensely in Rockwood. It felt good to work hard outdoors. This kind of activity also helps me remember that there is a tremendous amount of animal biomass right beneath our feet at any given time. In the city, one forgets much too easily that humans represent but a minuscule part of the biodiversity and biomass that can be found on Earth. The way we sometimes act shows just how removed we are from such realizations.