Reptiles

Eastern Milksnake

National Park Service

Different types of reptiles include snakes, turtles, lizards, and crocodilians. However, only snakes and turtles are common in the Upper Delaware region. Reptiles are ectothermic, also known as cold-blooded, vertebrates that have scaly skin. Their scales contain a unique type of structural protein called beta keratin, which is different from the alpha keratin found in the hair and skin of mammals. Since reptiles are ectothermic, they regulate their body temperature through external sources like the surrounding environment; this is known as thermoregulation. If it gets too hot, reptiles must cool themselves through shade or water to lower their body temperature.

 

Painted Turtle

National Park Service

Over the winter, when temperatures drop, reptiles may enter a form of hibernation called brumation. During brumation, their heart rate, body temperature, and metabolism decrease. However, if temperatures increase for a day or two, reptiles may stop brumation and emerge to bask in the sun or forage for food. For example, the Painted Turtle burrows into the mud at the bottom of marshes, ponds, and streams to enter brumation.

Visitors can find turtles and snakes in riverine, riparian, and terrestrial habitats along the river. Reptiles often take advantage of both aquatic and terrestrial habitats throughout their lifetime. For example, turtles may spend much of their time in the river but then move on land to lay eggs. By spending time in both types of habitats, reptiles help to transfer nutrients and energy between water and land.