Wisconsin's Native Salamanders
Salamanders are secretive creatures, so much so that most people never encounter them.
Because of their sensitive skin and
specific habitat requirements, these shy creatures can tell us a lot about the health of our environment.
Woodland salamanders are abundant in North American forests. They eat many small animals, from insects to spiders to worms. They
consume several creatures that people consider pests, such as slugs, mosquito larvae, and flies. They will also sometimes eat other
salamanders.
In a healthy deciduous forest, one having a good tree canopy and plenty of litter on the floor, nearly 3,000 salamanders can be expected
per hectare (approximately two and a half acres). This is twice the biomass of birds in an equal area. This fact again reinforces the
importance, as well as the inconspicuousness, of salamanders. Even though slimy, creepy-crawly critters turn a lot of people off, you
can rest assured that the salamanders of this region will continue to be among the best hiders of all wild animals, and also very important
members of many healthy forest food chains.
Unlike their cousins frogs, salamanders are rarely vocal. Instead, they communicate using touch and chemicals. To avoid predators,
they may exude bad-tasting substances. Some advertise their poisonous nature with bright colors.
In a healthy deciduous forest with a good tree canopy and plenty of litter on the floor, nearly 3,000 salamanders can be expected
per two and a half acres!
Breeding involves the male placing a sperm packet called a spermatophore on the ground or on detritus in a pool. The female inserts it into her
cloaca to fertilize her eggs, which she may attach to sticks and leaves or under rocks. Some species guard their eggs from predators until they
hatch.
Many young salamanders go through an aquatic tadpole stage in which they have visible feathery gills. When they become adults,
they may lose gills and gain eyelids and a tongue, as well as the ability to walk on land.
Tiger Salamander
Ambystoma tigrinum
Description: The Tiger Salamander is generally black with variable
yellow markings on its head, body, and tail. Newly transformed individuals sometimes have little or no
markings on a dark brown background and sometimes have black spots. Some specimens appear spotted
similar to the spotted salamander but many have larger irregular yellow blotches. Tiger salamanders have
deep costal grooves and five hind toes. The larvae are sometimes mistaken for mudpuppies, but
mudpuppies only have four toes on their hind feet. Tiger salamanders live in a variety of habitats including
grasslands, savannas and woods. They have adapted to living in agricultural and urban landscapes and
readily breed in farm ponds. Adults and larvae eat almost anything they can catch and swallow, from
earthworms and beetles to young rodents.
Spotted Salamander
Ambystoma maculatum
Description: The dorsal (back) side of the body is generally black or dark brown with prominent yellow
spots along the body, often appearing in two relatively distinct rows before merging into one on the tail. Often there are two orange spots at the
base of the head. Its sides have obvious costal grooves and the ventral (belly) area is light gray. Spotted salamanders prefer closed-canopy
hardwood forests with heavy ground-layer vegetation because of their cooler microclimates and higher humidities. They spend considerable
time underground during the warmer months and can sometimes be found under rotting logs or in humus during spring and fall. Spotted
salamanders eat earthworms, mollusks, and arthropods.
Redback Salamander
Plethodon cinereus
Description: Redback salamanders are the most abundant salamander
within their range and can be readily distinguished by the dorsal stripe that is normally brick-red in color,
although the stripe may sometimes be a dull brown. An occasional individual may appear unstriped. The
sides and bottom of its very slender body are brown to gray and heavily flecked with white. The hind feet
have five toes. Redbacks live in woodlands with moist soils and undisturbed ground cover. They are
commonly found in or under moist downed logs. Redback salamanders, because of their high densities, are
an extremely important component of Wisconsin’s northern forest ecosystems. They subsist on arthropods,
snails, and annelids.
Blue-spotted Salamander
Ambystoma laterale
Description: This is a relatively slender blue-black salamander with
whitish or blue spots on its back. It has four toes on its front feet and five on its hind feet. The costal (rib)
grooves are very pronounced along the body between the front and rear legs. A triploid variant of this
species, consisting exclusively of females, is found in parts of northern Wisconsin. The variants tend to be
longer and paler than the blue-spotted salamanders. Blue-spotted salamanders prefer both northern and
southern hardwoods and coniferous forests. They are often abundant in lowland hardwood forests. They
tolerate dryer conditions than most Wisconsin salamanders, often living in forests with sandy soils. Adults
eat many types of invertebrates including earthworms and insects.
Four-toed Salamander
Hemidactylium scutatum
Description: The four-toed salamander is aptly named because it has
four toes on its hind feet, while all other terrestrial Wisconsin salamanders have five. Its dark slender,
greenish-brown body is mottled with bronze and black, and its tail and limbs are a dull orange with gray
markings. The underside is bright white with black spotting. Four-toed's prefer northern and southern
hardwood forests and to a lesser degree, conifer swamps. Females nest in dense mosses growing along the
water’s edge of woodland ponds, springs and seeps or in dense moss on downed woody debris laying over
the water. Its unique breeding requirements appear to limit its abundance. Like many other salamanders,
their diet consists mainly of insects and other arthropods.