The Need for Turtle Conservation in Pennsylvania

Turtles, Quite Unique Creatures Indeed!

The term "turtle" is commonly used to refer to all members of the order Testudines, including aquatic turtles and the fully terrestrial turtles – known colloquially as "tortoises". Discreetly inhabiting the forests and waterways of Pennsylvania and abroad are creatures unique among wildlife. First appearing on Earth over 200 million years ago, turtles are often unseen by most humans. Turtles carry a dense shell comprised of their own modified skeletons covered with modified scales called scutes. Scutes are made of keratin, the same material that makes up your hair and nails! The colors on a turtle's shell may aid in camouflage, by allowing them to meld into the leaf litter of a forest or the sediment of a pond. Many turtles have a small home range and they often live their entire lives, spanning multiple decades, within the same area. A Maryland study conducted between 1947 and 1981 found the average home range of an eastern box turtle to be about 12,000 m², which is just a tad over two standard football fields (Stickel, 1989)!  Even though they are hidden, turtles are an integral part of natural systems and play an important role in sustaining environmental benefits.

Of the 356 described species of turtles, 57 are found here in the United States, most of which occur in the eastern U.S. Of the thirteen turtle species that inhabit Pennsylvania (Figure 1), nine are considered threatened, endangered, or a species of special concern by the state (Schneck, 2019). Part of the reason turtles are in decline is due to the life history traits of turtles, which cause them to have relatively low population numbers in today's heavily fragmented world, compared to other wildlife species. Turtles have high mortality rates in their early years, and only after reaching a certain age do they become "predator-proof". Once turtles reach this stage of maturity, they are able to reproduce throughout their lifetimes. This means that outside pressures can have a significant impact on populations. In order to protect turtles, it is important to understand how humans benefit from turtles and how human actions affect turtle populations.

Figure 1: Turtle species that can be found in Pennsylvania.

Eastern box turtle. Photo credit: Stephen Staedtler

Common snapping turtle. Photo Credit: Dave Emma

Midland painted turtle.  Photo Credit: Wayne Fidler

Eastern painted turtle. Photo Credit: Brandon Curtis

Wood turtle.  Photo Credit: Bob Hamilton

Eastern musk turtle.  Photo Credit: Don Becker

Bog turtle.  Photo Credit: Bob Bull

Northern map turtle.  Photo Credit: Don Becker

Spotted turtle. Photo Credit: Wayne Fidler

Blanding's turtle. Photo Credit: Jeff Hankey

Eastern mud turtle. Photo Credit: Brandon Ruhe

Northern red-bellied cooter Photo Credit: Stephen Staedtler

Eastern spiny softshell turtle . Photo Credit: Don Becker

*For more information about these species, click on their names! 

Turtles Make the World a Better Place

Turtles throughout the world are important to the plants and animals they interact with. Certain turtle species operate as ecosystem engineers, helping to create habitat for other small creatures, as a result of the burrows they create (Figure 2). Turtles also help plants thrive by stirring up the soil and facilitating the cycling of nutrients from the forest floor to various water bodies and vice versa. Turtles function at the intersection of food webs, by serving as prey for a variety of wildlife and operating as predators themselves (Lovich et al., 2018). They assist in growing plant communities by consuming fruits and flowers and distributing their seeds via their feces. Finally, turtles are important in aiding in the regulation of water quality for freshwater ecosystems by scavenging decaying and dead organic material (Santori et al., 2020).

Figure 2. Averaging 15 feet in length, gopher tortoise burrows provide habitat for over 350 species of wildlife.

For many, the value of protecting turtles is strongly linked to the presence of turtles in the landscape as part of a healthy functioning ecosystem. This is because many people believe that turtles have intrinsic value, or a value not assigned by humans, therefore they have a right to exist without the threat of being exterminated or expatriated (e.g., deported). Still, many humans value turtles outside of the ecosystems they inhabit. For example, turtles are a popular pet, due to their gentle demeanor and attractive shell patterns. In some places, turtles are considered a culinary delicacy and prized for their flavor. Among those who practice traditional medicine, turtles are thought to have important medicinal properties that can help cure certain ailments. Turtles worldwide are also part of important cultural narratives. They are often featured in stories that help humans share important ideas, an example being the famous fable "The Tortoise and the Hare". 

Are Turtles in Peril?

Even though turtles have a global distribution (found on every continent except Antarctica), they have one of the lowest species richness of any vertebrate group. For comparison, there are thought to be between 18,000 and 20,000 bird species existing today (Barrowclough et al., 2016). The unique life history traits of turtles (e.g., low reproductive success) and the minimal number of species altogether makes them sensitive to outside pressures on their populations.

Figure 3. Invasive red-eared sliders can dominate key resources, such as basking logs (shown here).

The international wildlife trade also places significant pressure on turtle populations because the removal of reproductive adults from the environment can destabilize local populations. The wildlife trade is driven by human demand for food, medicine, and pets. While discussions around wildlife trade are often dominated by charismatic megafauna such as rhinos and elephants, reptiles are particularly more vulnerable and susceptible to these actions. Conspicuous coloration and patterns, as well as varying levels of rarity, makes reptiles extremely desirable to consumers (Lyons et al., 2013). One important pressure on turtle populations is human movement into natural areas. Changes in land use often reduces habitat availability and degrades habitat quality. Pollution in waterways harms turtles either directly or indirectly through the contamination and death of aquatic plant and animal life that turtles rely on. Even when habitats are preserved, road construction can lead to increased turtle mortality from turtles attempting to cross. Humans can alter the natural balance in ecosystems by introducing new species of plants and animals. For example, the red-eared slider has become established as an invasive species in throughout the world and are a significant threat to many native turtle species. Often released into the wild by well-intentioned, yet overwhelmed pet owners, red-eared sliders mature quicker, grow larger, produce more offspring, and are more aggressive than their native counterparts. Red-eared sliders often out-compete native turtles for food, nesting sites, and basking sites (Figure 3) (Polo-Cavia et al., 2010).

Figure 4. These black pond turtles were seized on November 8th, 2013 in Thailand. Thailand serves as major transit hub in the international illegal turtle trade. Photo credit: P. Tansom/TRAFFIC

Due to the nature of illegal wildlife trade, it is difficult to quantify the number of turtles sold illegally (Figure 4). Individual U.S. turtles have been observed for sale on Chinese black markets for over $20,000 (Washington Post, 2020)! However, any illegal selling of turtles shouldn't overshadow the efforts of many to legally and ethically sell turtles. The propagation of turtles in captivity is thought to be a sustainable way to reduce pressures on wild turtle populations as well as guaranteeing healthy individuals at affordable prices. However, some argue that these actions further validate the existence of the industry and its profitability. Ongoing research at Penn State seeks to provide consumers with the information needed to switch to sustainable purchasing behaviors.  Recent events illustrate how the illegal wildlife trade is a threat to turtles in the U.S. In 2020, an international turtle smuggling ring was uncovered by the U.S. Fish and Wildlife Service (Washington Post, 2020). They found more than 1,500 endangered turtles were poached and shipped from the US to Asian countries, over a year and a half timeframe. The total value of this illegally traded wildlife topped $2.2 million. This kind of poaching doesn't require a large operation, for example, one person in State College, PA was found to have smuggled 79 eastern box turtles, an endangered species found in Pennsylvania, to collectors in Asia (Miller, 2019). These kinds of pressures from humans coupled with a low species richness contribute to why turtles are among the world's most imperiled vertebrate groups.

Why are Turtle Issues Not Well Understood by the Public?

Even though over 60% of the known turtle species have been classified as threatened or endangered (Lovich et al., 2018), it is the opinion of some conservation advocates that a disproportionate amount of attention and funding goes towards other more popular species, also referred to as charismatic megafauna (Hosey et al., 2020). This phenomenon is known as taxonomic bias. Charismatic megafauna are usually defined as large species with widespread popular appeal that help spread pro-environmental messages (e.g., the giant panda). While this kind of approach to conservation is well-intended, it may mean that many ecologically important species are disregarded.

The conservation of many reptiles is also hindered by the aversion humans have towards them (Janovcová et al., 2019). However, unlike snakes and lizards, turtles are received more positively by the public. This could be due to certain factors such as body shape and the perceived decreased threat. There are a few larger turtle species, like sea turtles, that benefit from the charismatic megafauna effect and consequently, receive increased publicity and funding. Although, it should be noted that sea turtles comprise just 2% of all turtle species. In fact, twenty-three of the most endangered turtle species assessed in a review by the Turtle Conservation Coalition were actually freshwater turtles and tortoises (Turtle Conservation Coalition, 2011).

What can you do to help?

There are multiple ways for everyday people to help turtles. First is to understand the types of pressures that turtle populations face from human actions and avoid these actions whenever possible. Work to protect wetlands and forest habitats in your community and the environmental quality within these habitats (e.g., manage waste disposal and stormwater runoff). Be cautious when driving on forest roads and interstates (Figure 5). If you see a turtle in the road, place it off to the side in the direction it was heading. However, in the case of a snapping turtle, it is best to just allow it to cross on its own.

Figure 5. As summer approaches, turtles begin to search for mates and nesting sites which results in increased road crossings.

Avoid collecting wild turtles as pets, they are needed to ensure robust reproduction in their natural community and are more likely to remain healthy in the wild. Do not release pet turtles into the wild, even if they were originally wild-caught as they could potentially become invasive or carry diseases. Instead, take steps to find the turtle a new home, whether that is with your local humane society, zoo, or an interested turtle owner. If you are interested in owning a turtle as a pet, seek out reputable breeders that engage in ethical practices.

Finally, support turtle conservation organizations and programs. This can be done through donations, volunteering, or simply by word of mouth. Shaver's Creek Environmental Center, located near State College, PA, offers students hands-on experience with their local wood turtle populations, with the goal of enhancing awareness of the need for increased conservation of the species (Figure 6). Contacting zoos is also a great way to increase the attention paid toward turtles. Zoos are often a driving factor in public awareness and play an integral role in advancing conservation activities (Landová et al., 2018).

Figure 6. A sign located near Shaver's Creek Environmental Center, alerting the public of potential turtle crossings. Photo credit: Paris Werner.

Conclusions

Turtles are important to ecosystems in Pennsylvania and abroad. Despite having their own armor and surviving a mass extinction event that wiped out more than 75% of Earth's species at the time, turtles are struggling to survive in the present Anthropocene landscape. It is not too late to reverse turtle declines, but the work must begin now and require a collective effort, so that these captivating creatures continue to traverse this globe for the next 200 million years.

You are invited to leave comments for the authors. 

A wood turtle. Photo credit: Julian Avery

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