Kinosternon flavescens

Geographic Range

Yellow mud turtles range throughout the midwest United States, from the northern parts of Mexico to as far north as Nebraska. Yellow mud turtles are also found in eastern New Mexico, Oklahoma, southeast Arizona and western Kansas. There are disjunct populations in northeast Missouri and central Illinois.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Yellow mud turtles are found in freshwater habitats. They are found in small permanent and temporary ponds. Yellow mud turtles are found mainly in smaller ponds with muddy bottoms with little or no vegetation. In arid regions yellow mud turtles can be found in cattle tanks, ditches, and sewer drains. When their small pools and ditches start drying up, yellow mud turtles can be found buried beneath the mud.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial
• freshwater freshwater

• Terrestrial Biomes
• savanna or grassland savanna or grassland

• Aquatic Biomes
• lakes and ponds
• temporary pools

• Other Habitat Features
• agricultural agricultural
• riparian riparian

Physical Description

Yellow mud turtles have high-domed carapaces. The scutes are rounded and smooth, but the ninth and tenth scutes are larger than the others. The carapace can be olive green, brown, or tan with the borders of each scute bordered in black. Males are slightly larger than females. Males have larger heads than females, but they are more flattened on top. The head, neck, and limbs are the same color as the shell, but the chin and cheeks are yellowish. Yellow mud turtles range from 10.2 to 15.2 cm in body length. Female yellow mud turtles have an average size of 11.4 cm, males are slightly larger with an average size of 14 cm. Average mass is 391 g.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes shaped differently

Development

As soon as yellow mud turtles have hatched the new young are nearly independent. Some female turtles stay with the young for a few days, but others abandon the eggs. Once hatched, these turtles begin looking for food.

Reproduction

There are three phases of courtship in mating: tactile, mounting, and intromission (biting and rubbing). The tactile stage involves a male turtle approaching another turtle with head extended to smell the tail to determine the sex. If the turtle is male, the courtship ends; if female, the male will nudge the area of her nose around the musk glands. The female will usually move away at this point and the male turtle will either follow her or go elsewhere. If followed the male turtle will attempt to bite and nip the female around her head. The male turtle will then mount the female, which can occur on land, in the water, or along the shoreline. This stage lasts from a few seconds to 3 minutes. The second stage of mounting then begins, with the male mounting on all fours and using its tail to grab and move the female's tail, after which copulation occurs.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Yellow mud turtles mate in April and May, a second period of mating occurs in September. Most nesting occurs during the springtime and hatching during the fall. Young turtles hatch and either spend the winter in a pond or bury themselves in the mud until spring. Yellow mud turtles usually have one clutch a year, but sometimes have a second clutch. The clutch size is typically 4 to 6 eggs. Female turtles become sexually mature at 5 to 8 years of age, males mature at 4 to 7 years old.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Female yellow mud turtles lay eggs on the surface of the ground or dig a shallow hole in which they lay the eggs. Once laid, females will often stay with their eggs for forty days, but some will leave after laying the egg. Most females only stay for ten to fifteen days with their eggs. After hatching, young turtles are entirely independent. Hatchlings either stay in a pond over the winter months or bury themselves in mud to overwinter.

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • protecting
    • female

Lifespan/Longevity

Yellow mud turtles have a lifespan of about fifteen years in the wild. Turtles in captivity have a lifespan of roughly ten years.

Behavior

Yellow mud turtles are seasonally diurnal. During the winter months they bury themselves underground and hibernate. They use their stout legs and claws to swim and to bury themselves in mud. When encountering other yellow mud turtles, male makes contact to determine the sex of the other turtle.

• Key Behaviors
• fossorial fossorial
• natatorial natatorial
• diurnal diurnal
• motile motile
• sedentary sedentary
• hibernation hibernation
• aestivation
• solitary solitary

Home Range

Yellow mud turtle home ranges are limited by pond size. Yellow mud turtles co-occur in ponds and are not aggressive among themselves. Yellow mud turtles wander from ponds in search of mates or in search of other water sources if food is scarce. On average, adult turtles will wander from 190 m to 220 m. Juveniles venture only about 180 m from the water.

Communication and Perception

Yellow mud turtles use touch to communicate with other yellow mud turtles. They use scent for social communication and to detect prey. Yellow mud turtles emit a strong musky odor when threatened by a predator.

• Communication Channels
• tactile tactile
• chemical chemical

• Other Communication Modes
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• chemical chemical

Food Habits

Yellow mud turtles are omnivores with a broad diet. Animals consumed range from small insects to amphibians and reptiles, as long as they are smaller than the turtle. Yellow mud turtles generally forage in the water, but sometimes find food on the surface of the water or on land. Their sense of smell and taste enable these turtles to locate food easily under water. Yellow mud turtles eat vegetation, carrion, fish, shrimp, crayfish, snails, and small clams. Yellow mud turtles also prey on the eggs of other turtles and fish. During dry seasons, yellow mud turtles bury themselves in mud or dirt and prey on earthworms, insects, spiders, and ticks.

• Primary Diet
• omnivore omnivore

• Animal Foods
• amphibians
• reptiles
• fish
• eggs
• carrion carrion
• insects
• terrestrial non-insect arthropods
• mollusks
• terrestrial worms
• aquatic crustaceans

• Plant Foods
• leaves
• algae

• Other Foods
• detritus detritus

Predation

Yellow mud turtles have few natural predators as adults. As eggs and young they are preyed on by skunks, raccoons, other turtles, water snakes, and large predatory fish. When yellow mud turtles are threatened they release a potent smell from their bodies which may repel predators.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Feces from Kinosternon flavescens helps with soil fertilization. Yellow mud turtles help regulate population size of small fishes and amphibians by feeding on the eggs of many species. Yellow mud turtles are parasitized by leeches, Macrobdella decora , which attach themselves to the skin of their legs and tails. Algae are also found on the shells of yellow mud turtles, including Basicladia chelonum and Basicladia crassa . Algae typically had no harmful effect on the turtle but, in rare cases the algae harmed the strength of the shell.

Economic Importance for Humans: Positive

Yellow mud turtles are important predators of fishes, snakes, and other turtles in their native ecosystems.

Economic Importance for Humans: Negative

Kinosternon flavescens flavescens was introduced to portions of Arizona and may have become an aquatic nuisance species there.

Conservation Status

Yellow mud turtle populations are stable throughout most of their range. Yellow mud turtles are not endangered or threatened in northern Nebraska through Texas and into Mexico. In Missouri K. f. flavescens is listed as state endangered. Kinosternon flavescens spooneri is on the state-endangered list in Illinois.

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Bradley Weiss (author), Radford University, Karen Powers (editor, instructor), Radford University.

References

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Tuma, M. 2006. Range, Habitat Use, and Seasonal Activity of the Yellow Mud Turtle (Kinosternon flaversens) in Northwestern Illinois: Implications for Site-Specific Conservation and Management. Chelonian Conservation & Biology , Vol. 5, Issue 1: 108-120.

Webster, C. 1986. Substrate Preference and Activity in the Turtle, Kinosternon flavescens flavescens. Journal of Herpetology , Vol. 20/ No. 4: pp. 477-482.