By Susan Benson,
CNHM Director of Education
With the forecast of a possible rain, it is difficult not to get excited, since it seems like a long time since we have seen precipitation in our area. One of the events I will be looking forward to is an event that happens yearly after the ground has thawed and the weather warms up. Salamanders are often on the move during the first warm, hard, night rain. Salamanders are amphibians not as well known as the spring peepers or other frogs because they are very secretive. In order to see one, it helps to be outdoors at night, as they are a mostly nocturnal animal. In Wisconsin, we have seven species of salamanders, whose cold-blooded body temperatures reflect their environments. They prefer night as they can take advantage of cooler, more humid conditions that keep their skin from drying out. They are most easily seen in spring and fall as they migrate to and from their breeding wetlands. With enticing names like newts, mole salamanders, lungless salamanders or mudpuppies, who could not want to learn more?
Where are salamanders in the spring? As soon as the edge of the ice is open, salamanders move from their terrestrial hiding places into their wetland habitats, usually ephemeral ponds (ponds that have been temporarily created by snowmelt and spring rains,) or in wetlands that do not support fish, major predators of salamander eggs and larvae. Breeding activity occurs when water temperatures are 50 to 60 degrees Fahrenheit. The spotted salamander breeds in large groups, while others breed in single pairs. The females often guard their eggs and secrete slime to prevent fungal growth or other destruction. Once hatched, the larvae fall into the pond where they develop until their final metamorphosis. The red-backed salamanders are an exception, being entirely terrestrial, looking for moist habitats to lay their eggs. The unique central newt can produce an aquatic adult, a terrestrial eft (juvenile) and a terrestrial adult.
Salamanders have some other interesting characteristics. Mole salamanders, commonly named the blue-spotted, tiger, and spotted salamanders, exude a defensive, sticky secretion that is foul-tasting to predators. They spend most of their time underground and eat a variety of invertebrates including insects, earthworms, mollusks, and even young rodents. These species can also sometimes be found under rotting logs. The central newt is primarily aquatic, yet also has toxic skin to protect itself. Newts eat earthworms, aquatic insects, snails, and other amphibian larvae. The lungless salamanders have four toes on their hind feet, while other species have five. The red-backed salamander is one of the most abundant species in Wisconsin, commonly found under rotting logs. Mudpuppies are exclusively aquatic, living in lakes and rivers with preferred large, flat rock habitats.
Like other reptiles and amphibians, salamanders shed their skin occasionally, often eating their skin sheds for the nutrients. Some salamanders protect their vital organs by arching their back downward, throwing back their head, and extending their tail over their back. Some salamanders will wag their tails or wiggle their bodies to distract a predator from attacking their heads. For some salamanders, their tails, when grasped, can break off and later partially regenerate. Salamanders also are able to re-grow toes or limbs, or even regenerate their eye tissue.
Salamanders are important for a variety of reasons. The red-backed salamander alone is thought to number in thousands per acre, making their sheer biomass important as a food source to mammals, birds, fish, or reptiles. They are also a predator of many insects or other invertebrates in aquatic or terrestrial environments. They are indicators of local environmental quality, as their permeable skin is vulnerable to pollutants. Maybe most importantly, for many children, one of their first experiences outdoors could be with a frog or salamander. Since my first experience looking for salamanders, I have never looked at a rotting log quite the same. Salamanders are worth carefully searching for as they are beautiful creatures.
For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.