Peep! Peep! Peep! No, not the candy, the spring peepers! These little frogs are singing every night now, signaling the start of spring. They’re joined by a chorus of wood frogs, also clamoring for attention. But frogs are not the only ones excited for warmer weather – their amphibious cousins, the salamanders, are waking up and on the move. It may still be chilly in April, but some nights are warm and rainy enough for the salamanders to start their yearly reproductive journey.
In New England, we have several species of mole salamanders (in the genus Ambystoma). The most commonly found species are the spotted salamander and marbled salamander. Marbled salamanders are an oddity, in that they actually mate and lay eggs in the fall, so their larvae overwinter in frigid ponds. The spotted salamanders, however, awaken as adults in the spring and prepare to start the next generation. They gravitate towards the ponds where they were born, forming mass migrations towards what we call “vernal pools”.
These are swampy, small ponds that are too shallow for populations of fish to live in – and in some cases, they dry up in the heat of the summer. “Vernal” means “spring”, so they tend to form early in the spring after the snow melts. Fish would hungrily eat up all of the salamander’s eggs and larvae, so these vernal pools are important for the survival of salamander species.
Once the salamanders arrive at a pond, it is time to find a mate. The eggs are laid in large jelly-like masses to protect them – the masses are usually about the size of a baseball! They look very similar to the egg masses left by frogs – such as spring peepers and wood frogs – also busily laying eggs in the same vernal pools. Once the deed is done the salamanders part, crawling back on land to find safe places to hide. They get the nickname “mole” salamanders because they spend most of their lives underground, where they eat worms and insects.
The egg masses float in the water, and if you look carefully you can see the baby salamanders developing and wriggling. Eventually they hatch, swimming out into the world. They start with feathery gills, legs, and a paddle-like tail. And while there may not be any fish, there are other predators to worry about – giant water bugs, predacious diving beetles, and marbled salamanders! That’s right, the marbled salamander larvae that hatched in the fall are quite big by springtime and ready to chow down on the tiny spotted salamander hatchlings. It’s a race to grow and develop – eventually losing gills, gaining lungs, rounding out the tail, and crawling onto land. Once on land, the salamanders start to develop their adult coloration and must learn to burrow. After a few years, they will be old enough to start their own journey back to the vernal pool where they were born.
If you want to see this exciting process for yourself, it may be tricky to find the right kind of pond – but if you follow the sound of the peepers, you might be in luck. Going outside on warm, rainy nights are best for spotting the action, especially if you have a good headlamp.
Want to support the salamanders in other ways? Be sure to watch the roads and avoid squishing our friends as they migrate toward the ponds. It’s safe to gently pick them up to transport them across the road (always in the direction they are walking in). Also, be aware that any swampy parts of your yard might actually be good salamander habitat – so if you see egg masses, avoid any temptation to drain the area. It’s also best to avoid any lawn treatments, such as pesticides, in the early spring. Those chemicals will wash into the vernal pools, potentially poisoning the salamander larvae.
Mole salamanders can live more than 10 years and are some of the most beautiful amphibians around. We are lucky to have such delightful creatures living in our area – and with our help, they will continue to thrive.
ABOUT DR. ZACHARCZENKO:
Brigette Zacharczenko is a science teacher at Talcott Mountain Science Center & Academy. She received her BSc in Zoology from McGill University (2010), and her PhD in Entomology from the University of Connecticut (2017). While she loves bugs, she’s passionate about all the world’s creatures! She teaches a variety of topics at Talcott Mountain Academy including Ecology, Biodiversity, Genetics, Botany, Anatomy, Cell Biology, and Marine Science. At our Science Center, she teaches hands-on biology courses for our summer, vacation, and Saturday programs. When she’s not concocting creative science lessons, she is finding new ways to combine science and art.
Sources and further reading:
Where Do Insects Go in the Winter? (Smithsonian)
Insect overwintering (Amateur Entomologists’ Society)
Insect overwintering in a changing climate (Bale and Hayward, 2010)
Insect adaptations to cold and changing environments (Danks, 2012)
Migration and overwintering (USDA)
The myth-busting mourning cloak (Mass Audubon)
Insect Dormancy: An ecological perspective (Danks, 1987)