Some salamanders are super cool looking, and are covered in awesome bright colours and fun patterns. Others are not, and today’s animal is one of those poor unfortunate amphibians that simply looks slimy and gross. But I would be the first to stress that just because an animal got shortchanged in the looks department, that doesn’t mean it is any less amazing. And dusty salamanders are no exception.
Dusky salamanders live in North America, in the eastern parts of Canada and the United States. In different parts of their range, the salamanders prefer different habitats. In the north, they like clear mountain springs, while in the south they seem to enjoy floodplains, sloughs, and muddy streams. Dusky salamanders spend most of their time hidden under rocks or logs. They are hidden from sight for as much as 70% of their lives, so don’t expect to see these guys darting around when you go for a walk in the woods.
As salamanders go, these guys are fairly average. Their average length is 9.4 cm for males and 8.6 cm for females. They range in colour from brown to grey to olive green, with some darker spots. Their colour lightens on their bellies, and is covered in speckles. As I said, dusky salamanders are really not very exciting looking.
Dusky salamanders belong to the family Plethodontidae, also known as lungless salamanders. Which means, of course, that these guys don’t have any lungs. Instead of breathing like most normal terrestrial animals, lungless salamanders absorb the oxygen they need from the air. This is done through their skin and special membranes in their mouth and throat.
Another distinct trait of lungless salamanders is a special slit known as the nasolabial groove. This is located on the snout of the salamanders and helps the salamanders with chemoreception. The salamanders use this sense to find mates and potential food items. You may now be wondering: what do dusky salamanders eat? The answer: gross things, like earthworms, slugs, a wide variety of insects, spiders and crustaceans.
As small animals, dusky salamanders are quite susceptible to predation themselves. They fall victim to raccoons, birds, skunks, shrews, snakes and other salamanders. Dusky salamanders are quick and agile, and have particularly slippery skin. This makes them quite difficult for a predator to grab. If a salamander feels really threatened, it can drop its tail and as a distraction for the predator, and then scamper away. The tail will then regrow, though it will not look the same as the original.
Dusky salamanders mate in the spring and fall, on land, but close to streams. A male dusky salamander has a peculiar dance he uses to approach a female: he does a ‘butterfly walk’, in which he swings his front legs like a swimmer performing a butterfly stroke. This is followed by tail wags and nudges on the female’s back. He then arches his body while pressing down on the female, and then straightens quickly, so that he is thrown back, sometimes as far as five to ten centimetres away. This process is repeated until the male makes his way to the female’s head.
Once the female is enamoured (thanks to the male’s bizarre advances), it is her turn to stimulate the male. She does this by touching the base of his tail with her chin. After staying like this for a while, the male will deposit a package of sperm called a spermatophore onto the ground, which the female will walk over and then pick up with her vent. The sperm is then stored inside her body until it is needed in the summer (meaning salamanders that mate in the fall store the sperm over winter), when the eggs are laid.
Female dusky salamanders lay between 12 and 51 eggs, which she lays under rocks, logs or other debris. She lays these near water, as the young are aquatic, and mother salamanders guard their nests until hatching. This occurs after 40 to 80 days, and the young sometimes stay with the mother for days or weeks before moving to water.
Although they are quite common overall, dusky salamanders are threatened in certain areas by habitat destruction and pollution. Removal of trees lets sun shine down onto salamander habitats, which heats up the water and lowers humidity. This is a big problem for salamanders that need to stay moist so they can breathe. Still, dusky salamanders are doing quite well, and let’s hope they continue to do so.