Amphibians, Pacific Northwest
The Pacific Northwest has a large & impressive population of Amphibians which includes frogs, toads, salamanders and newts. Some are almost always seen as individuals but sometimes they can be seen in the thousands, the western toad migration in between Courtenay and Campbell River is one example, you can watch them moving along toad fences as they are guided to culverts that take them under the highway as they head to or from their breeding grounds.
Most amphibians lay their eggs in water. After hatching, the young go through a larval stage with gills, and swim with fins, before becoming adults.
Although most species have lungs, they can also breathe through their moist skin and the lining of their mouths. Amphibians do not drink water but simply absorb it through their skin.
Amphibians are a part of our amazing web of life. They are a good measure of our role as keepers of the earth. They’re very sensitive to changes, especially those brought on by pollution. The health of our amphibians is a gauge of the health of the pacific northwest ecosystems.
The pacific northwest amphibians hibernate in winter. With the coming warmth of spring, they emerge and migrate to their traditional breeding ponds.
The males of frog species call to attract mates in a lively chorus, while voiceless salamanders find mates by scent. Mating and egg laying take place in the water, where eggs and larvae are left to face life alone. The eggs of amphibians develop rapidly and hatch into larvae. Frog and toad larvae, referred to as tadpoles, are good swimmers and feed on aquatic plants.
Salamander larvae eat insects, and quickly develop legs so that they can walk on the bottom of ponds. Over several weeks, the larvae transform into air breathing, land dwelling animals. Adult toads, newts and frogs, here, are most active in the spring & summer, and feed on insects and other small creatures. Salamanders are nocturnal, and hide under logs and leaf litter, coming out at night to feed. With the onset of freezing temperatures in late fall, amphibians retreat to their hibernating areas.
Reptiles on the island include snakes & turtles. Different from amphibians, they tend to have scaly skin, ear openings, & feel dry to the touch.
Reptiles usually lay their eggs on land. They are cold blooded, meaning that they don’t generate their own, internal heat. This is one of the main ways reptiles contrast from other animals, such as mammals and birds. Reptiles, though, must rely on their environment in order to regulate their body temperatures.
That’s why you see them soaking up the warmth of the sun during the day, and hiding in shelter at night, to conserve body warmth.
The skin of reptiles is covered with scales, which consist of a hard substance known as keratin, similar to human hair and fingernails. Scales are replaced periodically through a shedding process, in which the entire skin is sloughed off in one piece or flaked off in smaller pieces.