What Do Wild Turtles & Tortoises Eat?
Increasingly difficult to spot and trace in the wild, land turtles are a fragile group of reptiles. Able to hide in their tough carapaces and expertly blend in with their natural environments, these slow-moving creatures are endlessly fascinating. One would think that their almost sluggish way of living would incite boredom in most curious observers, but this is far from the truth. A turtle’s every action, including feeding, needs to be deliberate as it takes time.
Land turtles are more appropriately referred to as tortoises and terrapins. They are naturally found in the terrestrial zones and freshwater systems of several continents. Some of the most popular ones, which are often bred in captivity to meet the demands of the pet trade, hail from North America. These include common and ornate box turtles, snapping turtles, the painted turtle, and the red-eared slider.
The habitats in which these turtles live largely dictate their natural diet and the seasonal availability of their favored food types. As turtles occupy a wide range of habitats, they collectively have a diverse diet, signifying that they are able to thrive on many types of energy-rich food sources. To fully comprehend what wild turtles eat, it is thus important to go over the features of their wild habitats.
Wild Turtles in Their Habitats
The habitats of terrestrial turtles are usually located in grasslands, savannas, and woodlands with mild tropical to temperate conditions. Natural features vary depending on how pristine these locations are as well as how close they are to a body of freshwater. As there are turtles that principally remain on dry land (i.e. tortoises), their habitat types can be split into those for terrestrial turtles, basking aquatic turtles, and non-basking aquatic turtles.
Terrestrial turtles are highly adaptive and can thrive in prairies and open grasslands as well as forests and deserts. This classification includes many types of box turtles, which rarely venture into aquatic systems. Wild box turtles are able to burrow and dig into a variety of substrates. If they are found in the woods, they may remain close to vegetative areas where they are afforded cover and are more likely to find food. Giant tortoises, many of which are critically endangered, are principally land-based turtles as well.
Basking and non-basking aquatic turtles are those that gravitate towards freshwater systems, where they are able to find an abundance of food choices. Basking turtles, which include painted turtles and sliders, favor lakes, ponds, and streams with rocks, logs, and branches jutting through the water’s surface. Non-basking aquatic turtles live a mostly submerged lifestyle, feeding on animals that they find underwater or on the surface.
Feeding Habits of Terrestrial Turtles
Most terrestrial turtles are omnivores, so living in natural biomes with vegetation, stable populations of insects, and densely occupied substrates should meet all of their dietary needs. Some species may lean toward a more herbivorous diet, whereas others have a penchant for consuming grub and any decaying animal matter they come across.
Box turtles, for example, are opportunists that eat whenever they encounter food. As they are diurnal, they prefer to forage during daylight hours. Thus, they are more likely to consume insects and other small animals that are active when the sun is out. Tortoises are usually diurnal and likewise prefer to feed during the day. Healthy specimens are able to survive for long periods of time with minimal food. These terrestrial reptiles thrive best on a wild diet of the following items:
- Leafy greens
- Small insects
- Snails and slugs
- Caterpillars and millipedes
Land turtles don’t necessarily hunt for live food. Instead, they simply eat those that they are lucky enough to come across. As a result, they may gravitate towards areas that are rich in vegetation. Most of these areas, especially those that are pristine, are naturally filled with other protein-rich prey items.
Feeding Habitats of Aquatic Turtles
Basking and non-basking turtles often transition between freshwater and terrestrial environments. Some species prefer to remain in water, where they may find their chief sources of food, whereas others feed along the shoreline and around their basking spots. Principally aquatic species may be less skilled when feeding on land, and vice versa. A measure of plasticity when it comes to their biting behavior in water vs. land, however, does seem to work in their favor.
In the wild, snapping turtles are known for being voracious predators, able to quickly extend their necks and snap their jaws around anything that swims past them. They are able to sense vibrations in water and make use of all of their senses as they feed. Despite their seemingly vicious behavior, they are not strictly carnivorous. Mature individuals can remain perfectly content on a diet of lush greens and fruits found around ponds and lake systems.
Adult sliders, which are frequently seen perched on emergent logs and boulders, tend to have a principally herbivorous diet. Young specimens are more likely to consume live prey as their gut microbiomes are less developed. Females may also be more carnivorous, especially if they are nesting. Unlike snapping turtles, they don’t always have large and powerful jaws to snap at considerably-sized prey and stun them.
If aquatic turtles find themselves in highly productive ponds with many small prey types, they will forage in a true opportunistic fashion. In ponds like these, sliders are often partly submerged, with just their heads suspended above water. Aquatic turtles feed on a wide range of plant-based and live prey items. Some of their most common foods in the wild are listed below:
- Beetles, grasshoppers, and other semi-aquatic to fully aquatic insects
- Small amphibians and their larvae
- Snails and slugs
- Small reptiles
- Freshwater sponges
- Small fish
- Shelled animals, such as crayfish and clams
- Leaves and stems of herbaceous plants
- Flowers and seeds
- Fruits and nuts
How Climate Change Affects Food Availability
Freshwater habitats may naturally dry out in summer, forcing their aquatic turtle populations to migrate elsewhere for food and shelter. Due to climate change, aquatic biomes in both wetland and terrestrial systems are drying out at alarming rates. Ponds and lakes that are deep enough to remain filled with water become remarkably warm. These conditions significantly affect the availability of food for turtles.
At high temperatures, the locomotor performance of aquatic turtles becomes compromised. Young turtles, which tend to feed in deeper water for live, protein-rich prey, thus struggle to meet their metabolic demands during intensely warm periods. This may force them to find food in the shallows or along the coast of ponds and lakes, where their chances of being attacked by predators are increased.
Increasing temperatures also affect the reproductive success rates of many protein-rich prey types. The eggs of amphibians and freshwater fish, for example, may hatch at significantly lower rates in warm temperatures. This may leave aquatic turtles, particularly those with a preference for small fish and amphibian larvae, with less food. Heightened competition may drive out some individuals and force them to feed in areas with sub-optimal conditions.
Finding Food in Fragmented Environments
The conversion of wild sites into agricultural zones and urbanized areas has put many populations of land turtles at risk. Turtles travel from one place to another to search for potential mates, ideal nesting grounds, and sources of food. As more roads, highways, and modern developments encroach into their habitats, the risks to their survival are increased.
Due to habitat fragmentation, turtles may have to roam farther and wider to find spots where they can consistently feed and nest. Populations of their favored prey are just as affected. This leads to the significant loss of keystone predators that are further up the food chain. It certainly doesn’t help, too, that the delayed maturity times of turtles make them more vulnerable to rapid changes in nature.
Should You Feed Wild Turtles & Tortoises?
Though it may be tempting to feed wild turtles and even adopt them as pets, these seemingly generous acts may actually put their communities at higher risk. Feeding wildlife, in general, is usually a bad idea as it can cause animals to lose their wariness of humans. It encourages their dependence on us and may diminish their capacity to be self-reliant in the wild. Moreover, food that is sourced from urban areas may be contaminated with pesticides or have been exposed to other harmful substances.
One of the best ways to help wild turtles effectively obtain food is by creating a wildlife pond. This should be situated close to naturalized corridors that afford turtles cover from potential predators. As these vegetated ponds would serve as breeding grounds for many small critters, visiting turtles can almost effortlessly feed in their waters. They may even choose to nest nearby!