Mole Salamanders are pretty, big, and have extravagant lifestyles. They are cool and they are found only in North America. They make up the genus Ambystoma, the only genus in the family Ambystomatidae. The genus contains 32 species according to Wikipedia, and four of them are found in our fair state of Maryland: the Spotted Salamander, the Jefferson Salamander, the Tiger Salamander, and the Marbled Salamander.
These four species tend to be large as adults, exceeding 4 inches and in some species reaching 8 inches. They have distinct costal grooves, and all spend their larval stage in ponds, with characteristic pond larvae features: large gills to absorb oxygen in potentially stagnant water and thickly webbed tails to swim effectively in still water without the pressure to be “stream-lined” and have a smaller body surface area the way stream salamander large do.
Living up to their name, Mole Salamanders live largely underground as adults, for temperature regulation, to reduce predation, and perhaps for finding available food resources. Much of their underground lifestyle is elusive to the human eye, and even the variety of human known as “scientist”‘s eye, adding yet another layer of mystery and too-cool-for-schoolness to these BAs.
Because the larva are found in ponds or vernal pools, breeding and egg-laying meetups take place in these locations. In our area the four species are to some degree kept separate by the timing of their breeding periods.
Spotted Salamanders, dark with bright yellow spots, are the most common Mole Salamander in Maryland. They are found throughout the state except in the southern portion of the Eastern Shore. They come out to breed during the first night of warm rain in massive groups, often returning to the pond or pool of their birth (hatching). This takes place most often in March. The journey to the pond or pool from the wide area of the adult salamanders terrestrial distribution is a vulnerable time, particularly when road and other obstacles cross the salamanders’ historical paths. In some parts of New England Salamander Crossing signs and even bridges are provided to protect the journey. In the water, the adult males deposit a spermatophore and the females will select one to pick up in their cloaca, possibly after meeting and taking a liking to a particular male who will lead her to his sperm packet. The females then deposit clusters of eggs protected by a jelly-like coating.
These hatch into the pond-dwelling larva about a month later, and mature into sub adult salamanders. Perhaps because they are ectothermic, Spotted Salamanders have been documented living as long as 32 years. This means there may be some still barely kicking out there that are older than me!
Jefferson Salamanders are gray, brownish, or blackish and relatively unmarked; they are also smaller than Spotted Salamanders on average. Jeffersons breed at the same time as Spotted Salamanders, but are not as common in our state. The Maryland DNR lists them on the state Watchlist, but has downgraded them from threatened after larger populations were documented. They are in Western Maryland east to Montgomery and Frederick counties. I believe that they are most commonly (if not only) present in the western portions of Montgomery County.
(photo from Maryland DNR website)
The Marbled Salamander is dark, with white marbling on males and grey marbling on females. Subadults, smaller than the full-grown size and not yet breeding, also have grey markings.
The Maryland DNR lists Marbleds in every county but Garrett. They breed in the fall, with a less visible or predictable migration. The females may lay eggs in a dry area that will later be snow-covered and then flood; if they do this the female will guard her eggs until the water comes. The strategy of laying before the spring season is believed to allow the larva to grow quickly with easy access to food when other species begin breeding later in the year.
The Eastern Tiger Salamander is state endangered. Previously it existed on the Western Shore of Maryland, but the last population was destroyed in Charles County in the creation of a golf course in the 1960s. See this article: http://www.dnr.state.md.us/naturalresource/spring2009/salamanders.pdf
(photo from Maryland DNR website)
Currently this species is found breeding in Kent County and Queen Anne’s County. They breed in the winter, on the first night of rain that is not snow or ice, water just barely above freezing. They may be laying their eggs below the ice unseen while people walk by. This is a very pretty species, with a pale yellow rectangular pattern covering a dark background. They are the largest Ambystoma species in Maryland and our largest terrestrial salamander. It is frightening to think how entirely they have been lost from their historic residence, but the positive news for the Tiger is that they are not endangered throughout the East Coast; in some areas the populations are healthy.