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Last updated on April 20, 2014 at 21:20 EDT

Eastern Mole, Scalopus aquaticus

The eastern mole (Scalopus aquaticus) is also known as the common mole, and it is the only mole in its genus. This mole has a very wide range, the largest of any native North American mole ranging from Canada to the eastern areas of the United States, and as far south as Mexico. In the United Sates, this mole can be found in Texas, Nebraska, Kansas, Florida, Louisiana, South Dakota, and Wisconsin. However, it is not found in the Appalachian Mountains. Its Canadian range is limited to the southern tip, and is found in northern Tamaulipas, Mexico. Its populations are patchy in these areas. It is thought that some populations in southern Mexico and Texas may be extinct.

In 1976, a study of the eastern mole produced information on the population density and their mean home ranges. The study focused on seven moles during a period that lasted three years. It was found that the average home range of the moles was 1.8 acres, with males inhabiting an average of 2.7 acres and females .69 acres. The dispersal and gene flow of these moles was found to be limited due to fossorial territory, as well as the type of soil the moles burrowed in. Eastern moles are good at swimming, so water flow does not affect the dispersal. However, if there is hard clay in the area due to water sources, it will limit the range of the moles.

The eastern mole received its scientific name from Carl Linnaeus , who discovered a specimen dead in the water. This caused him label the mole aquticus, which is not true to its lifestyle. The first part of this moles name, Scalopus, means “digging” and “foot”, derived from the Greek words skalops meaning mole and pous meaning dig. This denotes the huge front feet of the mole, used to dig. The second part of its scientific name, aquaticus, means “found in water”. It was named so because it was literally found in the water, and because the webbing on its feet seemed to indicate that water was a part of the moles habitat. Its common name, eastern mole, is derived from its eastern range, and the Middle English term for mole (molle). Molle comes from the Middle English term molde-warpe which means “earth thrower”.

The eastern mole is a small mole, with an average length of 6.3 inches and average weight of 2.6 ounces. In this species, the males are larger than the females, with the largest males occurring in the northern Midwest. Sizes will vary depending on the location, however. In the Florida counties of Hillsborough and Pasco, the eastern moles are smaller than 5.5 inches and even smaller in an area north or Tampa Bay. The fur color of the mole is typically greyish brown, and can be paler on the belly. If viewed in the right lighting, the eastern mole appears to have a silver sheen. Males may appear to have an orange stripe on their bellies. This occurs more in male moles due to the skin secretion that occurs there. Albino moles can occur, and they appear to be white, or yellow-cinnamon in color. In the spring and fall, eastern moles will molt, and their new fur will first appear one their belly. The fur on the back will appear first near the tail and then move its way up, leaving a visible line between the new and old fur. The fur on this mole, when viewed under a microscope, has a tip similar to a whip, which is unlike any other fur on a mammal.

It is possible to determine the sex of an eastern mole by looking at the reproductive and urinary openings in the groin area. Males will have two, and females will have three. Each mole has six nipples on its belly, and there are scent glands located there as well. It is thought that the scent glands are used to mark territory when tunneling for navigational and breeding purposes.

The eastern mole has adapted to living underground. It is stout and has large front paws that it uses to tunnel through dirt. The nose of this mole is long and flexible, and it is used a tool for touching as well as smelling. The tail is also used for tactile purposes as it guides the mole when moving backwards through tunnels.  The eyes are very small, and covered by eyelids that have merged. The eastern mole can only differentiate between dark and light, but its sense of hearing is moderate.  The claws of the eastern mole are well developed, unlike the wide teeth. In order to help it dig, this mole has a sesamoid bone connected to the wrist. Both the hind and fore feet have little hairs on the ends that aid in sensitivity when tunneling. The hips are narrow, allowing the mole to flip over and double back if necessary.

Eastern moles prefer moist, lush soils to burrow into, and these can be found in meadows, fields, pastures, and woods. Moles will dig both shallow and deep burrows, characterized by extra piles of soil tunneled from the burrow called “molehills”.  Deep burrows are used permanently, while shallow burrows are used for foraging. Tunnels can be excavated as deep as 9.8 inches, and are convenient for escaping hot or cold weather. Moles can breathe in their tunnels even when the oxygen levels are as low as 14.3 percent. The nests of moles are lined with leaves and grasses and are typically found under stumps, bushes, or boulders. In Florida, eastern moles have been known not to make nests.

The eastern mole is active throughout the day, with peak activity occurring around dusk and dawn. The diet of this mole consists of mainly earthworms, but they will eat centipedes, slugs, snails, scarab beetle grubs, and ants. Vegetation is also consumed in great amounts. Moles are known to be ravenous eaters, and when in captivity, will eat nearly anything including dog food and ground beef.

Eastern moles can produce litters between two to five young between the months of April and June. In warmer locations, baby moles can be born in March. The babies are blind and hairless, and quite large in comparison to the mother. They will start growing a pale grey fur at ten days, and at almost four weeks, they are ready to be weaned. Mole vocalizations include rough guttural squeaks, high-pitched squeaks, and small snorting noises. They will also grind their teeth.

The eastern mole has a conservation status of least concern, most likely due to its adaptability do changing habitats, large range, and lack of threats. Predators of this mole include dogs, cats, foxes, and coyotes.  The eastern mole is known to host many parasites including fleas, beetles, and mites. Through a study of one hundred and four moles, a new beetle genus was formed, called Scalopacarus. Moles can live to be 3.5 years to six years of age depending on the location, and they will show signs of aging such as damaged teeth and skull shrinkage.

For humans, moles are not usually pests. They do not feed on crops and instead of damaging lawns and soils, they provide a convenient means of aeration.  Moles will eat cut worms and Japanese beetles, which are destructive to crops. Human activities such as the building of roads and golf courses actually provide more habitable areas for these moles because this causes soils to be of high quality. Fossils of the eastern mole have been found in the upper Ohio Valley in Pennsylvania, in Pleistocene cave faunas in Texas, and in West Virginia.

Image Caption: A photograph of Scalopus aquaticus. The eastern American mole (Scalopus aquaticus linnacus) showing the large forelimbs used to excavate tunnels. Credit: Kenneth Catania, Vanderbilt University/Wikipedia

Eastern Mole Scalopus aquaticus