Northern two-lined salamander facts for kids
Quick facts for kids Northern two-lined salamander |
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The northern two-lined salamander (Eurycea bislineata) is a small salamander found in Canada and the United States. It belongs to the Plethodontidae family. These salamanders live in places like temperate forests, rivers, and even urban areas. They love water and are often found near rain puddles, streams, and swamps. This is different from their relatives, the northern redback salamanders, who prefer damp ground but usually not open water.
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What Does It Look Like?
The northern two-lined salamander is quite small. Adult salamanders are usually between 6.5 and 12 centimeters (about 2.5 to 4.7 inches) long. They are yellow or yellowish-brown. They have two black stripes that run down their back. These stripes often break up after the base of their tail. Their sides are grayish or brown, and their belly is a pale yellow, almost clear. They have four toes on their front feet and five toes on their back feet. You can also see 14 to 16 grooves on the sides of their body.
Where Do They Live?
These salamanders prefer small, rocky streams or wet spots in forests. However, they can also be found in moist areas far from water. Sometimes, they live on the stony shores of small lakes and rivers. Northern two-lined salamanders live across northeastern North America. Their range goes from central and southern Quebec, New Brunswick, and northeastern Ontario in Canada. In the United States, they are found from central Virginia and Ohio north to the Great Lakes. This species has a very wide distribution compared to many other salamanders in its group.
Life Cycle and Reproduction
The northern two-lined salamander has a special way of finding a mate. This can happen from September in the south to May in the north.
First, the male salamander looks for a female. When he finds her, he might lift her head or chest with his snout. Then, the male bends his body around her snout. They can stay like this for a long time. The female then moves to straddle the male's tail with her front legs. She presses her chin against the base of his tail. The male might slowly wave his tail from side to side. The female moves her head from side to side, touching his tail. This "tail-straddling walk" can last for over an hour.
After this, the male drops a small packet of sperm called a spermatophore. The female walks over it and decides if she wants to pick it up. The sperm packet is shaped like a cone, about 2.5 millimeters tall.
Male salamanders have special teeth during breeding season. These teeth are longer and sharper than the female's teeth. They use these teeth to gently scratch the female's skin. This helps a special liquid from the male's chin gland get into her body. This liquid encourages her to mate.
Before laying eggs, the female looks for a good spot in the stream. She often chooses to lay her eggs under rocks or sometimes logs. To lay eggs on the underside of a rock, she flips onto her back. It takes about three minutes to lay each egg. Laying a whole group of eggs can take several hours. Freshly laid eggs are white or pale yellow. Each egg is about 2.5 to 3 millimeters wide. Sometimes, many females lay their eggs together in the same spot. This has been seen in New York, Ontario, and Ohio.
Young Salamanders (Larval Ecology)
When the eggs hatch, the young salamanders are called larvae. They are about 1 centimeter (0.4 inches) long and have gills. They stay in slow-moving pools or hide in cracks between rocks in streams. Larvae start eating after they absorb their yolk sacs. They crawl along the bottom of the stream, looking for tiny water insects. They eat things like midge larvae, stonefly larvae, and small crustaceans.
Many animals eat young salamander larvae. These include fish, crayfish, and even other larger salamander larvae. For example, the northern spring salamander eats them.
How long they stay as larvae depends on where they live. In warmer southern areas, they might change into adult form (metamorphose) when they are about 5 centimeters long or two years old. In colder northern areas, they might be nearly 7 centimeters long or three years old before they change. Larvae spend the winter in deeper pools that do not freeze.
Adult Life
Once the larvae grow to their full size, they change into adult salamanders. They become ready to reproduce when they are three to four years old. Adult and young salamanders usually stay near the edges of streams. They hide under rocks and other things during the day.
Some adult salamanders move away from the stream after breeding. Research in Quebec shows that some adults move into the forest in June. They might travel over 100 meters from the stream. Young salamanders that have just changed into adults also leave the stream. However, they tend to stay closer to it. Most of their movements happen after dark and when the weather is wet.
Adult salamanders eat a wider variety of food than larvae. This is because they can hunt in both land and water. They come out from their hiding spots after dark to look for food. Their diet includes wood roaches, spiders, worms, beetles, snails, and flies. Sometimes, they even eat small trout.
The number of salamanders in an area depends on how good the habitat is. Adults can be territorial, meaning they defend their space. If there isn't much food, there will be fewer salamanders in one spot. In some places, there are only a few salamanders per square meter. In other areas, there can be as many as 11 salamanders per square meter. In cold places, adults spend the winter buried up to 80 centimeters (about 31 inches) deep in the soil near the stream bank. In warmer areas, they might stay active and keep eating during winter.
How They Protect Themselves
Because they are small and live near streams, many animals hunt the northern two-lined salamander. Birds like the eastern screech owl eat them. Snakes such as the eastern garter snake and ringneck snake also prey on them. Other salamanders, like the large northern spring salamander, eat the larvae.
When a northern two-lined salamander faces a predator, it might react in different ways. Some will stay still if a snake touches them. If the snake's tongue touches them, they might do a quick flip, holding their tail over their body. Losing part of their tail is common for these salamanders. This is called "tail autotomy." It helps them escape from a predator. In some groups of salamanders, up to 32% of them have lost part of their tail.
