Salamander Season

Above: spotted salamander, Ambystoma maculatum.

Lizard? Worm? Something in between? Salamanders, like frogs and toads, are amphibians. Despite their mild superficial resemblance to lizards, they aren’t reptiles – though they are cold-blooded. As ectotherms, their activity is limited by temperature; in the winter, they’re largely inactive, and in the summer, they’re going about business as usual. However, when certain conditions are met, it is possible to find salamanders as early as February. In fact, your greatest chances of seeing more than one at once are probably in late February and March!

So what are those magical conditions? Fifty degrees, raining, and dark – as in nighttime. They aren’t hard and fast, because you might find a few moving slow if temperatures are closer to forty-five degrees, but the salamander runs with the highest traffic occur when all three of these conditions are met. This year, we had the right temps at the right time, but didn’t quite hit the mark with a heavy rain. Still, spotted salamanders were on the move with the steady sprinkle we did receive, along with a few spring peepers, wood frogs, red-spotted newts, and a pair of long-tailed salamanders.

Above: A spring peeper hovers near the edge of a pool. Several of the pools we have here at Wahkeena were actually built as water features for Carmen’s garden but have long since been used as breeding grounds for several amphibians. 

And what exactly do we mean when we refer to this mass movement of salamanders in the spring as a run or “migration”? Again, we acknowledge that salamanders are not reptiles, which would have dry, scaly skin, but amphibians, which have soft skin lacking scales that is often wet with mucus to preserve moisture. Additionally, they spend part of their life in water and part on land. Like many frogs, most salamanders, such as the spotted, start life as eggs laid underwater. There, they develop for a few weeks until they hatch, looking a lot like tadpoles. How long they exist as larvae in the water varies by species and is affected by variables like water temperature, but eventually, they metamorphose into their adult form and leave the water. At that point, they’re capable of living on land because they no longer use their gills for respiration – instead, they now breathe with their lungs (if they have them), their skin, or a combination of both. 

Wait, some salamanders don’t have lungs?

Correct – salamanders of the Plethofontidae family don’t have lungs. But they still need oxygen, so how do they get it? A process called cutaneous respiration, where oxygen is absorbed through their skin, whether they’re in water (remember water, H2O, is two hydrogen molecules and one oxygen molecule) or on land. However, this process can only take place if their skin adequately moist. If their skin dries out, essentially, they can’t breathe and, if left like that, will die. They keep their skin wet enough by inhabiting moist environments, such as underneath a log or in an underground burrow. They’re also largely nocturnal, keeping them out of the sun’s drying rays. 

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Above: These long-tailed salamanders, photographed at Wahkeena, are members of the Plethodontidae family. Below: Red-backed salamanders, a woodland species that does not utilize vernal pools and actually lays their eggs on land where they will develop fully inside their eggs and hatch as adults without gills, are also plethodontids.

Above left: Red-backed salamander eggs discovered beneath a log. Above right: A red-backed salamander found in late February.

This all ties back to migration because when it’s warm enough at night for the salamanders to be active, the rain allows them to traverse long stretches of land to the very vernal pool they once hatched from to mate and lay their own eggs. These very specific conditions may only happen a few days, and so the salamanders must take advantage when they can. 

Above: A spotted salamander on the move.

Males and females alike will congregate in the water, some in amplexus, where the male latches onto the female and waits for her to lay eggs so he may fertilize them externally, and some where the male will deposit a spermatophore for the female use to fertilize her eggs at her discretion. 

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Top left: wood frogs in amplexus. Top right: Wood frog embryos. Bottom middle: Wood frog tadpoles.

This all must take place in the vernal pools because by nature, vernal pools are temporary; they fill with water from snow and spring rain, and by the end of the summer dry up, meaning they can’t support predators such as fish who would consume the eggs and larvae. By the end of the summer, the larvae should have developed enough to drop their gills and be able to begin life on land.

Above: Spotted salamander egg mass at Wahkeena.

Above: Salamander eggs, attached to sticks. Notice the fluffy white debris on the pool floor that resembles cotton swab heads. Those are spermatophores from the previous night.

Above: Salamander eggs mid-development.

Above: Salamander larva with noticeable gills.

Above: Red-spotted newts may hunt during the day, even feeding on other salamander eggs. They are somewhat of an anomaly among salamanders in that after metamorphosing from larvae to adult, they leave the water to spend 1-2 years on a land in a terrestrial form referred to as a Red Eft, and then return to the water where they’ll remain for the rest of their lives. The name comes from their bright red coloration that tells predators such as birds, snakes, frogs, and mammals like raccoons, that they’re toxic and best left alone.

Above: An adult spotted salamander may live 20-30 years!

– Naturalist Leah