The Carlisle Mosquito Online

Friday, October 3, 2003


Four-toed Salamander

(Photo by Kay Fairweather)

Name: Hemidactylium scutatum or Four-toed Salamander. The genus name refers to the deficiency in the toe department. The species name from the Latin scutatus, meaning armed with a shield, refers to an alleged armor-like look of the body. It is a member of the plethidontid family of salamanders which are woodland-dwelling and lungless. (They breathe through their skins.) The common name, salamander, has Greek origins and translates roughly to "Fire-Lizard." It was long thought that salamanders were immune to harm from fire, could extinguish fire with skin secretions, and could even get nourishment from fire.

When and where found: Leslie Thomas of Estabrook Road found a pair of four-toed salamanders underneath an old log at the edge of her yard on September 11.

Distinguishing characteristics: Most salamanders have four toes on their front feet and five on the hind feet. As you might have guessed from its name, this little fellow has four toes on all four feet. You have to catch it to count the toes. There are two additional characteristics that identify it as a four-toed · the white belly with black specks and the constriction at the base of the tail. It is the smallest salamander found in Massachusetts, reaching only 3.5 inches in length. The back is reddish brown or gray-brown going to grey on the sides. There are 13 or 14 grooves along the body which supposedly give it an armored appearance. With this specimen, some imagination was needed.

Working its tail off: The four-toed salamander is able to shed its tail to escape predators. It doesn't have to be in the grasp of an enemy · it can do it voluntarily by pushing against an object. The newly detached tail wags vigorously for several minutes with the goal of distracting the predator. This division into parts where one part gains an advantage at the expense of the other makes one wonder if a better name would be the gerrymander salamander.

Look-alikes: The mudpuppy, which also has four toes on the hind feet, is significantly larger, has external gills, and lives in the water. The redback salamander can be of a similar size and color but has neither the black-specked white belly nor the tail constriction. The redback also has five toes on its hind feet.

Habitat: Adults are terrestrial and are generally found in damp, mossy, wooded areas not too far from the breeding habitat which is wetland with lots of moss overhanging bogs, swamps, slow-moving streams or vernal pools. The females nest in little holes in mounds of sphagnum moss immediately above the water. When the eggs hatch, the larvae wriggle around until they drop into the water where they may stay for as long as 18 weeks before becoming adults and leaving the water. The four-toed salamander is extremely vulnerable to loss of habitat since it has rather specialized requirements. It is less vulnerable to acid rain since it has a preference for the acidic environment of sphagnum moss.

Rare species program: The Massachusetts Division of Fisheries and Wildlife maintains a list of rare species that are classified as endangered, threatened, or of special concern. "Endangered" is the most serious status. The four-toed salamander is of "special concern," defined as "native species which has been documented by biological research or inventory to have suffered a decline that could threaten the species if allowed to continue unchecked, or which occur in such small numbers or with such restricted distribution or specialized habitat requirements that they could easily become threatened within Massachusetts." The full list of rare species can be found at nhrare.htm. If you find a rare species, you are encouraged to report it to the National Heritage and Endangered Species Program. The form is at

References: Leo P. Kenney, Matthew R. Burne, A Field Guide to the Animals of Vernal Pools;

Submissions for the Biodiversity Corner are encouraged and welcomed from all interested observers of nature. Think of it as your space to say a word or two on behalf of one of your favorite species. Just follow the format of today's column (or not) and send to Kay Fairweather at 392 School Street, Carlisle MA 01741 or to Don't hold back due to lack of photos or drawings.

2003 The Carlisle Mosquito