What Is It Wednesday: Midland Painted Turtle

Name: Midland Painted Turtle (Chrysemys picta marginata)

Who doesn’t love baby turtles?! Here at TTLT, we are obsessed! When turtle nesting season arrives, we call up the turtle experts and scan the countryside, hoping to safely secure as many nests as possible for the incubation lab. We then impatiently wait for fall, when all the hatchlings start to poke their little, baby heads out of their cozy eggshells. Of the eight species that occur in Canada, Midland Painted
Turtles are one of the more common types of turtle nests that we find in the field.

Midland Painted Turtles are one of three subspecies of Painted Turtles that occur in Canada (Western and Eastern Painted Turtles are the other two) and is the one you’re most likely to find in southwestern Ontario (see Figure 1). All share the similar features of a smooth, dark green to black upper shell (i.e. carapace) with a pattern of large scale shapes, a tan to yellow under shell (i.e. plastron) with a dark, irregularly shaped blotch in its centre, and red and yellow stripes along their necks and heads. However, the Midland subspecies is the only one that sports colourful markings of red and orange along the sides of its upper shell. This subspecies usually grows to be 12-14 cm long, but it is possible for them to grow longer.

Females reach sexual maturity between the ages of 6-10 years and for males it takes up to 6 years. Nesting occurs between late May and early July, which is when you will notice more turtles along the side of/crossing the road. Females love to lay their eggs in sandy and gravelly soils within 200 m of a water body, making roadsides and road shoulders the ideal nest material, if not the ideal location. On average, Midland Painted Turtles lay 8 elliptical shaped eggs in a dugout nest about 10 cm deep. Hatchlings will start to emerge between 60-90 days after being laid and will leave the nest immediately at night to the nearest waterbody or will wait until the following spring (the preferred approach of more northern populations). Hatchlings are roughly 25 mm in diameter and are attracted to reflections of water – this is how they find the closest water body – but can sometimes be deceived by the reflections from roads and parking lots. If they happen to make it to the water, they will spend most of their time hiding from predators and eating lots of aquatic insects, small fish, leeches, snails, and small frogs.

For one of first turtle releases of the year, we had 7 baby Midland Painted Turtles. Emily, Sophie, Annie, Georgia, Kathe, Kenojuak, and Frida were named after Emily Carr, Sofonisba Anguissola, Annie Pootoogook, Georgia O’Keeffe, Kathe Kollwitz, Kenojuak Ashevak, and Frida Kahlo, all of which are female painters. This was done for two reasons. One, they are all Painted Turtle babies (painters, painted – get it?), and two, the probability of them all or mostly all being female is very likely. When turtle eggs are hatched in incubation labs, temperatures are adjusted to produce a larger ratio of females to males. This is primarily because females experience a greater rate of road mortality from travelling overland and nesting during the breeding season. Incubation laboratories play an important part for turtle survival rates. Many nests are predated by skunks, foxes, and raccoons, especially if they are closer to urban populations or where there is an abundance of human activity (these predators are drawn to human activity for food and shelter purposes). Add the loss and degradation of wetland habitats to road mortality and nest predation and you can see that turtles have a really hard time. Because wild populations of Midland Painted Turtles can live a very long time (over 30 years) and take many years to become sexually mature, it can take decades before one baby turtle is able to survive from egg to adult long enough to replace its momma. Estimates suggest that it would take 59 years for one snapping turtle to be replaced, and this just isn’t happening enough anymore (see the reasons above) to maintain species populations. Luckily, there are other organizations and programs out there dedicated to the protection and survival of our native turtle species.

Fun Fact: A turtle’s sex is determined by the amount of heat it receives as an egg. Warmer temperatures produce more females, whereas cooler temperatures produce more males.

Figure 1: Midland Painted Turtle range in Canada (http://canadianherpetology.ca/species/species_page.html?cname=Midland%20Painted%20Turtle).