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How do turtles choose and prepare nesting sites?

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A painted turtle (Chrysemys picta) with a dark shell and red and yellow markings rests on a rock near water, surrounded by green aquatic plants. — reptile Painted turtle (*Chrysemys picta*).

Turtles exhibit a fixed behavioral pattern for nesting, which involves careful site selection followed by the excavation of an egg chamber.

Site Selection

Females of all aquatic species must leave the water to find suitable nesting conditions. Some species nest on banks adjacent to their home streams, while others travel hundreds of meters across land to find appropriate sites. Many sea turtles are migratory, traversing vast distances to return to the specific beaches where they hatched. River-dwelling turtles often seek out large sandbars for this purpose. In some cases, females return to the same nesting colony year after year.123

Nest Preparation

Once a female finds a desired site, she digs an egg chamber exclusively using her hind limbs:

Excavation: The female uses alternate scooping movements. While one hind limb supports her body, the other reaches under her tail to spade soil and flip it to the side. This continues until the chamber reaches a depth equal to the length of her outstretched hind limbs.13
Deposition: She centers her tail over the opening and drops her eggs into the chamber.13
Closure: After laying, she uses her hind limbs to drag loose soil back into the hole to fill it before departing.13