Moles, shrew moles, and desmans

(Talpidae)

Class Mammalia

Order Insectivora

Family Talpidae

Thumbnail description
Small, often long- and narrow-snouted mammals, many with large forelegs, and small or hidden eyes suited to a fossorial lifestyle

Size
Average adult total lengths (including tail) range from about 2.4–17.0 in (6–43 cm), with tail lengths of 0.6–8.3 in (1.5–21.5 cm) and weights of about 0.4–7.8 oz (12–220 g)

Number of genera, species
17 genera; 42 species

Habitat
Depending on the species, they may prefer fossorial, terrestrial, or aquatic habitats

Conservation status
Critically Endangered: 2 species; Endangered: 5 species; Vulnerable: 4 species

Distribution
North America and Eurasia

Evolution and systematics

The family Talpidae includes the moles, shrew moles, and desmans. Some taxonomists consider the desmans (Desmana and Galemys spp.) different enough from the other talpids to deserve a separate family status, but this chapter discusses them with the talpids.

The Talpidae is usually divided into three subfamilies—Uropsilinae, Desmaninae, and Talpinae—as it is here. Two other subfamilies, Scalopinae and Condylurinae, are occasionally separated out of the talpins, which is the largest subfamily.

The talpins contain 14 genera. Among that number are several genera, including Mogera, Parascaptor, and Scaptochirus, which have recently been split from the large Talpa genus.

The subfamily Uropsilinae has one genus. Taxonomists now regard its formerly lone taxon as four separate species. The subfamily Desmaninae has two monotypic genera.

Evolutionarily, the talpids are believed to have originated in Europe, and spread from there throughout Eurasia and into North America.

Physical characteristics

The typical talpid is a small, tube-shaped mammal with short, silky fur, and a narrow muzzle. The fossorial (burrowing) forms, which make up more than half the species in this family, have large, clawed hands specialized for digging, small or unseen eyes suited to their dark habitat, and fur that lies flat regardless of whether it is pointing backward or forward on the body. The aquatic and the terrestrial, surface-dwelling species lack the exaggerated forefeet, and some aquatic taxa have webbed or enlarged hind feet that propel them through the water.

Talpids also have distinctive short necks and limbs. The enlarged upper arm bone, or humerus, articulates with the collarbone,

or clavicle, and the forefeet are turned outward rather than down. This combination of features permits a strong, side-ways sweeping action that is efficient for digging or swimming.

Conspecific males and females are commonly similar in appearance, although the average male is often a bit larger.

Distribution

This Northern Hemisphere family occurs in North America, Europe, and Asia. In the New World, it ranges throughout the United States, and reaches into southern Canada and northern Mexico. In the Old World, talpids live in temperate climates from the Mediterranean Sea to Japan and north well into Russia.

Some species exist over a wide area. The European mole (Talpa europaea), for example, is spread throughout Europe and into Russia. More geographically limited species include the greater Japanese shrew mole (Urotrichus talpoides), which occurs only in Japan, and the Gansu mole (Scaponulus oweni), which lives in a small area within central China.

Habitat

The talpins are chiefly fossorial, the uropsilins prefer an above-ground lifestyle, and the desmanins are semi-aquatic. The fossorial talpins exist in forests and/or fields with some opting for wet soils close to water, and a few, like the star-nosed mole (Condylura cristata), frequently leaving their tunnels for a swim. Besides the uropsilans, some species of the talpins, like the American shrew mole (Neurotrichus gibbsii) are mainly surface dwellers. These uropsilan and talpin moles that live above ground commonly shun open spaces, instead scooting beneath leaf litter or under a log, but many are known to climb into shrubs and trees. Semi-aquatic species generally favor freshwater, although a few species, such as the Russian desman (Desmana moschata), will sometimes venture into brackish water.

Behavior

As a whole, moles are best known for their tunnels, even though some talpids are not fossorial species. Evidence of tunnelers' activities is often visible as "mole runs" that zig-zag across an otherwise level lawn or forest trail. The runs are actually the roofs of the tunnels. These shallow tunnels are usually feeding runs, which the mole uses to seek out subterranean earthworms or other invertebrates. Moles can make the shallow tunnels rather quickly, with the eastern mole (Scalopus aquaticus) tunneling at a rate of up to 15 ft (4.6 m) an hour. Their activities are also frequently evident as molehills. While they pack some dirt to make the walls of the tunnel, fossorial

moles typically push the leftover dirt from deep-tunnel excavations to the surface, where it forms small molehills. Molehills are usually only 6–12 in (15–30 cm) in diameter and 3–6 in (8–15 cm) tall. Deeper tunnels provide living quarters, breeding sites, and, in winter, protection from cold weather. Moles will also retreat to deeper tunnels during periods of summer drought.

Semi-aquatic species may also utilize burrows for mating or as winter shelter, but spend the bulk of their active hours in the water rather than underground. Some, like the Pyrenean desman (Galemys pyrenaicus), prefer fast-flowing streams and rivers, while others like the Russian desman, favor slow-moving streams and lakes. Surface-dwelling species are likely to find shelter under a log or leaf litter instead of a subterranean tunnel.

Active day and night, most moles are solitary animals, although some will share the same foraging grounds. In this case, they usually continue to maintain their distance from one another, often by covering the same area but at different times of the day. The Russian desman appears to be more social than other moles, and will not only share foraging tunnels but, in at least one case, its den.

Feeding ecology and diet

Talpids make good use of their Eimer's organs, which are sensory receptors on their snouts, to identify and perhaps to locate food items. The organs, which contain nerve cells, respond to touch and may also pick up seismic vibrations. The latter would help a fossorial mole, in particular, to hunt prey items in the dark tunnels. Some scientists suggest that talpid moles, including Condylura species, may also be able to feel vibrations through their forepaws. Despite these interesting adaptations possibly used in hunting, burrowing talpids seem to find most of their food by simply bumping into it while moving through their tunnels.

Swimming species, on the other hand, do appear to engage in active hunting, and are able to catch even small fish. Several fossorial, terrestrial, and semi-aquatic talpids also eat vegetative matter, but the primary diet item is invertebrates.

Predators mainly are larger mammals, including domestic cats and dogs that will unearth fossorial moles. Talpids' strong musky odor, however, often repels attackers.

Reproductive biology

In general, moles in the family Talpidae mate from late winter to late spring, with a single litter born from mid- to early summer. The schedule within a species can be moved up by a month or so among populations in warmer climates. Some moles, such as the greater Japanese shrew mole (Urotrichus talpoides), have a second litter in the summer or early fall. Gestation typically lasts four to seven weeks, with the young weaned three to four weeks after birth. Litter size averages three or four young, but can range from just one to seven or more. The young attain sexual maturity within their first year. Life span averages three to four years. Mating system varies among species.

Conservation status

Nearly a quarter of the species in this family are threatened. According to the IUCN, the list includes 10 of the approximately 42 talpid species. The Russian desman, Japanese mountain mole (Euroscaptor mizura), and Pyrenean desman are Vulnerable. The sado mole (Mogera tokudae), Echigo Plain mole (Mogera etigo), Ryukyu mole (Nesoscaptor uchidai), Yunnan shrew-mole (Uropsilus investigator), and Chinese shrew-mole (Uropsilus soricipes) are Endangered. The small-toothed mole (Euroscaptor parvidens) and Persian mole (Talpa streeti) are Critically Endangered.

Significance to humans

Burrowing moles are perhaps best known to humans for their tunnels, which are the bane of gardeners and farmers, as well as homeowners who desire a perfect lawn. Few realize that mole activities help turn over and aerate the soil, or that they feed on a considerable quantity of harmful insects, particularly beetle larvae and slugs.

Species accounts

List of Species

American shrew mole

Neurotrichus gibbsii

subfamily

Talpinae

taxonomy

Neurotrichus gibbsii (Baird, 1857), Naches Pass, Washington, United States. Three subspecies.

other common names

English: Gibb's shrew-mole, least shrew-mole; German: Amerikanischer Spitzmull, Amerikanischer Spitzmausmaulwurf; Spanish: Topo musaraña americano.

physical characteristics

The body length is 3.5–5.2 in (8.9–13.2 cm), and the tail is 1.0–1.6 in (2.5–4.0 cm) long. Average adult weight ranges from 0.32–0.39 oz (9–11 g). A shiny, black to dark gray mole with a thick, hairy tail and only faintly widened hands. Males and females are similar.

distribution

Along the North American coast from southwestern British Columbia in Canada to central California in the United States.

habitat

Occurs in forests and shrubby areas, usually near a water source.

behavior

Although this mole does make burrows for resting, it also spends considerable amounts of time above ground, often scurrying through leaf litter or climbing into shrubs. It is also able

feeding ecology and diet

Active day and night, this mole searches for food along the substrate in leaf litter and above ground in shrubs. It eats earthworms, insects, other invertebrates, and occasionally fungus or vegetation.

reproductive biology

Polygamous. Little is known about its reproductive biology, but it appears to produce several litters of one to four young each year.

conservation status

Not threatened.

significance to humans

None known.

Eastern mole

Scalopus aquaticus

subfamily

Talpinae

taxonomy

Scalopus aquaticus (Linnaeus, 1758), Philadelphia, Pennsylvania, United States. Sixteen subspecies.

other common names

French: Taupe à queue glabre; German: Ostamerikanischer Maulwurf; Spanish: Topo de agua.

physical characteristics

Adults range from 5.9–7.9 in (15.0–20.0 cm) in total length, and 0.8–1.5 in (2.0–3.8 cm) in tail length. Adults generally weigh 3.2–5.0 oz (90–143 g). On average, males are slightly larger than females. An often glistening, stocky mole with brownish gray, sometimes black fur. It has a short, hairless tail, and large, wide feet sporting long claws.

distribution

Eastern half of the United States, except the far northern reaches. Extends south to extreme northeastern Mexico.

habitat

Although it has webbed feet and its species name is aquaticus, this mole shuns aquatic habitats, opting instead for the moist, sandy or loamy soils of forests and fields, as well as lawns, and other cultivated areas.

behavior

This is a solitary, fossorial mole, making shallow tunnels for foraging and deeper tunnels up to 2.5 ft (0.8 m) underground for winter denning. The shallow tunnels are evident as trails, or "mole runs," of loose dirt across the forest floor or a lawn. This mole also makes small molehills, which are piles of dirt pushed out of the tunnels and onto the surface.

During breeding season, moles make a large room, and line the floor with grass and leaves for a nest.

feeding ecology and diet

This species is an omnivore. Its diet includes mostly insect larvae and earthworms, but it also eats other invertebrates, including slugs and centipedes, as well as roots and seeds. Predators include hawks and owls during the rare occasions when the mole is on the surface, or digging mammals, such as foxes, and domestic cats and dogs.

reproductive biology

Promiscuous. Mating occurs in early spring, with a litter of three to five altricial young born 40–45 days later. Females have only one litter per year. The young are weaned at four to five weeks and become sexually mature by the following spring.

conservation status

Not threatened.

significance to humans

Moles are a pest species to many gardeners who lose crops to their foraging, and to homeowners who find their impeccably groomed lawns irregularly patterned by mole trails.

European mole

Talpa europaea

subfamily

Talpinae

taxonomy

Talpa europaea Linnaeus, 1758, Engelholm, Sweden. Four subspecies.

other common names

English: Mole, common mole; French: Taupe, taupe d'Europe; German: Europäischer Maulwurf; Spanish: Topo europeo.

physical characteristics

The total length is 4.7–5.5 in (12–14 cm), with the tail 0.8–1.6 in (2–4 cm) long. Average adult weight ranges from 2.1–4.2 oz (60–120 g). Gray mole with a long snout, vertically oriented fur, and shovel-like hands. The back is dark gray, sometimes black, and the belly is lighter gray. On average, males are slightly larger and darker than females.

distribution

Temperate Europe to western Russia.

habitat

Ranges from forests to fields, not as common in farm fields, and seldom in sand dune areas.

behavior

Fossorial moles that often use common, existing tunnels from previous generations. These common tunnels service many moles. Individuals do, however, construct shallow foraging tunnels that are used only by that one mole. Like many other fossorial talpids, this species builds a nest of leaves during breeding season in an underground chamber within the tunnel complex.

feeding ecology and diet

This carnivorous mole primarily eats earthworms, which it identifies mostly by touch. On occasion, it will also kill and eat small snakes, lizards, rodents, and birds. This species is known to maim earthworms so that they are unable to dig their own escape burrows, and store the captives alive for later consumption.

reproductive biology

Probably promiscuous. Mating occurs in the spring, with a litter of three to four altricial young born 28 days later. Females typically have one litter per year. The young are weaned at four to five weeks and become sexually mature at six months.

conservation status

Not threatened.

significance to humans

Gardeners, farmers, and homeowners typically regard this species as a pest because of its tunneling lifestyle. Its tunneling also aerates the soil, but this benefit is rarely acknowledged.

Hairy-tailed mole

Parascalops breweri

subfamily

Talpinae

taxonomy

Parascalops breweri (Bachman, 1842), eastern North America.

other common names

English: Brewer's mole; French: Taupe à queue velue; German: Bürstenmaulwurf, Haarschwanzmaulwurf.

physical characteristics

The total length is 5.5–6.7 in (14.0–17.0 cm), with the tail 0.9–1.4 in (2.3–3.6 cm) long. Average adult weight ranges from 1.4–2.3 oz (40–65 g). Males are generally larger than females. Dark brown, sometimes black mole with a hairy tail. It has the wide, clawed hands and tiny eyes typical of burrowing talpids.

distribution

Eastern United States and southeastern Canada stretching from northwestern South Carolina and northern Georgia at its southern extreme to southern Ontario and Quebec in the north.

habitat

Prefers sandy or loamy forests, fields, lawns, and other cultivated areas.

behavior

This fossorial mole spends most of its time in its shallow, foraging tunnels or in deeper tunnels that provide winter protection. It also employs the deeper tunnels as breeding sites, where it constructs a grassy or leafy nest. The shallow tunnels are narrow and just deep enough to at most only minimally disturb the surface. Its mole hills, however, are evident. Hairy-tailed moles are generally solitary, but not territorial, and conspecifics as well as other small mammals may also traverse its tunnels.

feeding ecology and diet

Day and night, this mole forages for food, which includes earthworms, beetles, and other invertebrates, including slugs and centipedes, and an occasional plant root. Predators are the same as those listed for the eastern mole, but also include short-tailed shrews (Blarina brevicauda), which sometimes prey on newborns.

reproductive biology

Probably promiscuous. Mating occurs in early spring, with a litter of three–six altricial young born about 30–40 days later. Females typically have one litter per year. The young are weaned at about a month and become sexually mature at 10 months.

conservation status

Not threatened.

significance to humans

This species' tunneling behavior can damage lawns and gardens.

Russian desman

Desmana moschata

subfamily

Desmaninae

taxonomy

Desmana moschata (Linnaeus, 1758), "Habitat in Russiae aquosis."

other common names

French: Desman de Russie; German: Russischer Desman, Bisamrüßler, Wychochol; Spanish: Desmàn almizclado.

physical characteristics

The total length is 7.1–17.0 in (18–43 cm), with the tail 6.7–8.3 in (17–21 cm) long. Average adult weight ranges betwen 3.5–7.8 oz (100–220 g). Unlike other genera, the desmans have long guard hairs interspersed in their otherwise short fur coat, and webbed hind feet that are larger than their forefeet. Their pelage varies from a rusty brown dorsally to light gray below.

distribution

Major river basins of Russia, Belarus, eastern Ukraine, and Kazakhstan.

habitat

This semi-aquatic species lives in and near freshwater areas, including lakes, ponds, slow rivers, and marshes. It occasionally enters in brackish waters.

behavior

This is a mainly aquatic species, although it uses shoreline burrows for both shelter and breeding. When water levels are high, it will move its nest to a drier site, sometimes into nearby trees or shrubs. It spends much of the year in shallow ponds, marshes, and streams, then travels to a deeper lake to spend the winter. Several members of this species may share a tunnel system, and even the same den.

feeding ecology and diet

A mainly nocturnal species, the Russian desman's diet includes insects, crustaceans, mollusks, amphibians, and small fish.

reproductive biology

Little is known about the reproductive biology of this species, but mating is believed to occur in both spring and fall, with a litter of typically three to five young. Probably promiscuous.

conservation status

Listed as Vulnerable by the IUCN. The major threats to this species include habitat loss, competition with introduced species (such as muskrats), and water pollution. Preservation efforts include nature reserves and refuges, as well as reintroduction attempts.

significance to humans

This species was once hunted for pelts, but that activity is now banned.

Star-nosed mole

Condylura cristata

subfamily

Talpinae

taxonomy

Condylura cristata (Linnaeus, 1758), Pennsylvania, United States. Two subspecies.

other common names

French: Condylure étoilé; German: Sternmull; Spanish: Topo de nariz estrellada.

physical characteristics

Adults range from 6.1–8.1 in (15.5–20.5 cm) in total length, and 2.2–3.5 in (5.5–8.8 cm) in tail length. Adults weigh 1.1–3.0 oz (30–85 g). Males and females are similar. Brownish black, silky-furred mole with wide, shovel-like hands, distinctive tentacles surrounding the nostrils. The 22 fleshy tentacles are short and pink.

distribution

A North American species, this mole ranges from Labrador and Nova Scotia west to Manitoba, through the Great Lakes region of the United States and to South Carolina. A few spotty populations extend to coastal Georgia.

habitat

These semi-aquatic and fossorial moles live in damp- or soggy-soiled meadows or forests near water sources, such as marshes, swamps, streams, and lakes. Occasionally they will reside beneath lawns that are near water.

behavior

The most noticeable feature of star-nosed moles is their tentacles, which are constantly in motion as the animal moves through its habitat. Once suspected of being capable to detect electric fields, the tentacles are now believed to have a tactile function, and help guide the animal through its tunnels or identify prey.

Evidence of star-nosed moles comes in the form of molehills, which are piles of dirt pushed out of the tunnels by the moles. Tunnels are generally shallow in the summer, and deeper in the winter. Some tunnels open into the water, where the mole will swim throughout the year, especially in colder months when terrestrial prey is scarce. During the winter, the star-nosed mole may also retreat into the deeper burrows to escape the cold, or emerge on land to burrow through the snow. This species commonly overwinters in small colonies, occasionally in male-female pairs.

feeding ecology and diet

Star-nosed moles are active foragers day and night, either finding earthworms, insect larvae, and other invertebrates in their tunnels, or swimming to hunt aquatic invertebrates, or an occasional small fish or crustacean. This mole also forages above ground.

Predators include birds of prey, snakes, fish, skunks, cats, and other mammals.

reproductive biology

Mating occurs from late winter (in southern populations) to early summer and produces a single litter. May form monogamous pairs. In a dry nest made of leaves, grass, and other vegetation, the female gives birth to two to seven altricial young following a gestation of about 45 days. The young are independent at three to four weeks and become sexually mature at 10 months.

conservation status

Not listed by the IUCN, but its habitat has decreased as wetlands have been drained for human uses.

significance to humans

This species typically lives in areas unsuitable for lawns, gardens, or farms, so is not usually known as a pest.

Resources

Books

Gorman, M. L., and R. D. Stone. The Natural History of Moles. Ithaca, NY: Comstock Publishing Associates, 1990.

Kurta, A. Mammals of the Great Lakes Region. Ann Arbor: Universtiy of Michigan Press, 1995.

Nowak, R. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press, 1999.

Wilson, D., and S. Ruff, eds. The Smithsonian Book of North American Mammals. Washington, DC: Smithsonian Institution Press, 1999.

Yates, T. L., and D. W. Moore. "Speciation and Evolution in the Family Talpidae (Mammalia: Insectivora)." In Evolution of Subterranean Mammals at the Organismal and Molecular Levels. New York: Alan Liss, 1990.

Periodicals

Catania, K. C. "A Comparison of the Eimer's Organs of Three North American Moles: The Hairy-tailed Mole (Parascalops breweri), the Star-nosed Mole (Condylura cristata), and the Eastern Mole (Scalopus aquaticus)." Journal of Comparative Neurology 354 (1995): 150–160.

Hebert, P.D.N., ed. "Star-nosed Mole, Condylura cristata." Canada's Aquatic Environments University of Guelph, <http://www.aquatic.uoguelph.ca/mammals/freshwater/accounts/mole.htm>

Mason, Matthew J., and P. M. Narins. "Seismic Signal Use by Fossorial Mammals." American Zoologist 41, no. 5 (November 2001): 1171–84.

Yokohata, Y. "Biology of the Shrew Mole and Moles in Hiwa, Hiroshima Prefecture, Japan." Recent Advances in the Biology of Japanese Insectivora, Proceedings of the Symposium on the Biology of Insectivores in Japan and on the Wildlife Conservation. Hiba Society of Natural History and Hiwa Museum for Natural History. <http://yokohata.edu.toyama-u.ac.jp/Hiwarev.html>.

Organizations

IUCN Species Survival Commission, Insectivore Specialist Group, Dr. Werner Haberl, Chair. Hamburgerstrasse 11, Vienna, A-1050 Austria. E-mail: [email protected] Web site: <http://members.vienna.at/shrew/itses.html>

Other

IUCN 2002. 2002 IUCN Red List of Threatened Species.<http://www.redlist.org>.

Mole Tunnel. <http://www.moletunnel.net>

Talpa europaea L. Mammalia, Insectivora, Talpidae. HYPP. <http://www.inra.fr/Internet/Produits/HYPPZ/RAVAGEUR/6taleur.htm>.

"Talpidae." Discover Life.<http://www.discoverlife.org/nh/tx/Vertebrata/Mammalia/Talpidae/>

Leslie Ann Mertz, PhD