World Turtle Weekend
Written by Katie Zajac, all photos by Tharusha Wijewardena
What’s a better way to get into World Turtle Weekend than by learning about turtle surveys?! My name is Katie Zajac and I am a Master of Environmental Science Candidate at UofT, collaborating with the Adopt-A-Pond program at the Toronto Zoo. Every day this summer will be World Turtle Day for me, and I’m excited to share my experience so far in turtle surveying.
The spring, summer, and fall is when many wildlife species are out and about, but the group I’m most excited for are the turtles (shocker, I know!). From Blanding’s to Painted to Snappers, oh my! What a great summer it’s going to be!
Working with a team of experts dedicated to turtle research, specifically Blanding’s turtle conservation, we have started the season by spending time in wetlands and capturing turtles. Basically, we’re living the dream! Turtles can be captured by hand and in hoop traps. Hoop traps are used to safely capture turtles, while still allowing every turtle the room to breathe and the ability to move enough to adjust their body temperature. This behaviour is called thermoregulation, and turtles typically do this by sunning themselves on logs to warm up, and by spending time in shaded areas underwater to cool down in the summertime.
Our conservation research goal is to determine the demographics of Blanding’s, Painted and Snapping turtles in the Rouge National Urban Park. This includes the number of turtles, the ratio of males to females, and the number of juvenile vs adult turtles. To do this, all turtles found are measured, determining the length and width of each individual’s carapace (top portion of shell) and plastron (bottom part of the shell). Height and body mass are also measured using calipers and a scale.
Based on the size and weight of a turtle, we are able to identify the age range of that turtle. This gives us vital information as to when a turtle may be ready to mate and if hatchlings should be expected that year. We also insert a PIT (Passive Integrated Transponder) tag in the hind leg of the turtle, so that when we find a turtle, we are able to easily determine if the turtle was from previous years or if it is a new turtle to the study. This information helps us to estimate the population size for each species of turtle.
While handling turtles, we also determine the sex of the individual based on physical characteristics, but this is only possible for adults. In Painted turtles, female turtles have shorter nails on the front legs than males. Additionally, examination of a turtle’s tail will indicate whether an individual is female or male. A male turtle’s tail is longer and thicker, with the cloaca (the opening used by a turtle to urinate, defecate and mate) positioned closer to the end of the tail, as it stores the male sex organ (penis). For this reason, female turtles usually have shorter, thinner tails than males.
Through turtle surveys, we are able to learn not only about each turtle species, but we are able to assess whether the populations are in good condition and will persist for future generations.