Behold the Turtle

An Evolutionary Success Story on the Brink of Extinction

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This post has been added to the Seeing your Place archive. Back in July of 2022 I wrote about the concept of ‘umwelt,’ which has to do with imagining the sensory experience of another species. I think it’s important to learn more about the other inhabitants who share your place because of an experience I had about 15 years ago, while completing a Masters degree in Earth Literacy.

I was living in Indiana at the time and one of my assignments was to pick a natural place that I could visit for at least 20 minutes every week over the course of the semester. I chose a pond in a city park close to my home. We were to observe, draw, photograph, write, or whatever we felt called to do in response to the place. It was the winter semester so the pond was covered in snow and ice when I began and by the end, it was springtime. For our grade, we had to submit our journal entries and also do a research project on two species we’d encountered there. Once the warmer weather came, I would often find turtles basking on logs in the pond, so that was one of the species I chose to write about. 

I’ve felt a special connection with turtles since my early 20’s. I’ve always been a quiet person and my best friend at that time was an extreme extrovert. She gave me a framed copy of the quote above and decided I should collect turtle merchandise. I do have a few ceramic turtles and turtle earrings but that’s about it. More importantly, I have great respect for turtles.

An Evolutionary Success Story

Turtles are one of the most ancient living reptiles, as fossil evidence indicates their presence 210 million years ago. Today, there are more than 300 species worldwide, even though many are now endangered. The turtle’s protective shell is its most distinctive feature and is probably most responsible for its success. The upper, domed part of their shell is called the carapace while the lower, flat part is called the plastron. 

Turtles are ectothermic, or ‘cold-blooded,’ meaning they don’t generate their own body heat, so they are more reliant on the temperature of their environment. This is why they’re often found basking in the sun. They have a preferred optimal temperature zone for moving, eating, mating, and staying healthy. Therefore, they can’t survive in very cold climates and must hibernate in the winter to warmer areas. ​Turtles in colder climates tend to hibernate during the winter in mud, underground or underwater. Some can actually hold their breath for up to four months. Cold water also holds more dissolved oxygen and turtles can exchange gasses through parts of their neck.

You can usually find turtles living in shallow water because they don’t like currents. This type of environment also provides a variety of foods and basking sites. Turtles eat a variety of foods, both plants and animals, including aquatic insects, leeches, snails, crayfish, small fish, and tadpoles. They also eat algae and other aquatic vegetation and carrion, the carcasses of dead animals. ​Although they don’t have teeth, they can rip their food with the edge of their jaw. They are an important link in the aquatic ecosystem because they keep these populations in check. 

Turtle predators include large fish, mammals (raccoons, skunks, foxes, squirrels, snakes), and some predatory birds (herons). Humans have eaten turtle meat (in soups and stews) for more than 2 million years causing the extinction of many species. However, their hard shell and the fact that they can tuck their heads into it have helped them to avoid predation.

Generally, invasive species threaten the biodiversity of ecosystems. One example is purple loosestrife, which is known to take over wetland areas displacing many native plants, which affects all wildlife, including turtles. Since turtles eat a variety of foods, less variety would affect them. 

Box turtles mostly live on land, but all turtles lay their eggs on land. I learned that ​turtles in Indiana are active from March through October, with breeding occurring in the spring. The females bury their eggs underground in May and June and they hatch about two months later. Females do not care for their young. The temperature of the soil determines their sex during the second trimester; if the temperature is above a certain point offspring are male and if it is below they are female, with the exception of the Spiny soft shell Turtle, which has sex chromosomes.

More than 60% of turtle species worldwide are now endangered, ​mainly due to habitat loss, pesticide use, collection, hunting, road kills, and predators. Development by humans has led to these effects. Some turtle species do not reach sexual maturity until they are more than 15 years old, making them particularly vulnerable. Many female adults are killed on roadways while searching for places to lay their eggs. However their long life spans and the fact that they mate several times and produce many eggs has served them well.

Another factor in their future survival, as it is with all species, has to do with climate change. While the physical structure of turtles has allowed them to survive ice ages and other environmental catastrophes, they are still sensitive to pollution, just like the rest of us, and scientists are wondering how they will survive since their sex is determined by soil temperature. Increased temperatures could lead to an unbalanced ratio of female to male turtles and eventually lead to their extinction. Rising sea levels could also lead to eventual loss of habitat for sea turtles.

The Qualities of Turtles

This past month, I read a beautiful heartwarming (and heartbreaking) book by Sy Montgomery called Of Time and Turtles. It was mainly about the amazing people who devote their lives to turtle protection and conservation.

The things that happen to turtles because of poaching, habitat degradation, and roads are terrifying. But, the people who take care of injured turtles and even develop relationships with them before returning them to the wild, give me hope. There is much work being done in locating and protecting nesting sites and rehabilitating injured turtles and then releasing them.

As I was finishing the book, I visited Pinery Provincial Park in Ontario with my sister and brother-in-law and was delighted to discover several frames protecting nesting sites, educational materials about turtles, and we even had an encounter with a snapping turtle. 

What can we learn from turtles? In this book, the people who work with endangered turtles describe the qualities they’ve come to know and appreciate as they develop a relationship with these magnificent creatures. Here are a few examples from the book. 

Turtles’ eyes are really special. There’s something about the way a turtle looks at you, even briefly, that feels like more than a glance. It’s the intensity of their focus. Nobody pays attention like a turtle. 

They are survivors because nobody is as patient as a turtle. They never give up and are champions at waiting. In the north, they practice each winter when they enter, and sustain for months, a state of semi-suspended animation, called brumation. It allows turtles to cheat death by emulating it. They don’t eat or breathe for long periods of time; their way of adapting. Metabolism may decrease by a full 99%. Some species even freeze solid and still survive. 

Turtles are shy creatures, wisely concealing their lives from our unwelcome scrutiny. With their shells, turtles literally embody the concept. They cannot come out of their shells since they’re fused to their skeleton. The shell is one reason turtles have persisted so long on Earth, and why they have long lives. 

What species would you write about that you have a special kinship with? Tell us about that relationship in the comments.

Resources

Of Time and Turtles (Bookshop)

Turtle Facts