The Red-spotted Newt (Notophthalmus viridescens) has what some would consider an unusual life cycle, even for a salamander. Many salamanders lay their eggs in water and once the larvae mature they leave their aquatic nursery to continue their lives on land. Some salamanders are completely terrestrial, living their entire lives, from egg to mature adult, on land. And some salamanders are completely aquatic, spending their lives in water. But the red-spotted newt is a different story.
Adult red-spotted newts are aquatic (though some will overwinter on land, especially if their pond dries up in the winter). They can live up to 15 years. They mate underwater and the females lay hundreds of eggs, one at a time, on submerged plant stems and leaves. The tiny larva that hatches from an egg matures in a few months, and its skin transforms from a smooth yellow-green to a rough-textured orange-red with small red spots encircled with black. It leaves the water to live in moist woodlands. Behold, a Red Eft is created! But wait.
This is only the juvenile stage. Unlike most other land-dwelling salamanders, the red eft is not a secretive creature and can often be seen walking along the forest floor during the day, especially after a summer rain. Its bright orange coloration warns predators that secretions in its skin are toxic and they had better leave it alone. It will spend two to five years, possibly up to nine years, living on land in this red eft stage, feeding on small invertebrates on the forest floor. And then another transformation begins.
As the red eft matures into an adult red-spotted newt, its coloration changes once again. What was once a brilliant orange juvenile becomes an olive-green adult. (It keeps the red spots encircled in black.) And, it heads back to the water.
If the larval and adult stages of the red-spotted newt are aquatic, why on earth does its juvenile stage move onto land? Well, an eft can travel great distances, by salamander standards, in the many years it spends as a juvenile. Its wanderings allow it to discover and colonize new bodies of water, such as beaver ponds. Some believe that the red-spotted newt has evolved this unusual life cycle to take advantage of changes in the landscape, especially those created by the North American beaver.