ORDER INSECTIVORA - Insectivores 

                                 SHREWS                                   MOLES

                             

Insectivores are the descendants of the most primitive placental mammals and are the predecessors of all other placental mammals.  Earliest known fossils date back 130 million years ago. Some members of this order seem to have departed less from the form of the generalized, primitive mammalian type than have any other recent placentals.  For this and other reasons, certain insectivores are believed to resemble the basic stock of certain placental lines of descent.  Among the primitive features that many insectivores exhibit are the structure of the ears, the small brain, primitive teeth, testes that are usually inside the abdomen rather than in a scrotum, and the joining of the urinary and reproductive tracts and the intestine into a common channel called a cloaca.  These insect-eating mammals have long-pointed, flexible snouts with a finely developed sense of feel (some are carnivorous). Their sight and hearing are poorly developed, and they all have musk glands, like the weasel family.  They have five clawed toes on all four feet, in contrast to rodents, like mice, that have only four toes on their forefeet.   These very small, non-hibernating mammals have high metabolic rates and may consume up to twice their body weight per day. Most insectivores are ferocious predators with an insatiable appetite, with a constant need to forage. Shrews have a very short life span and high reproductive rate. Many exhibit post-partum estrus, with the female becoming pregnant within hours of giving birth. The pygmy shrew is the smallest mammal in North America.

Worldwide, the Insectivora order includes seven families, 68 genera and 440 species (according to Nowak's Walker's Mammals of the World).  Most are found in the palearctic, Ethiopian, and Oriental regions.  More than 70% of the Insectivora are shrews.  Other members of this order include hedgehogs (Eurasia and Africa), solenodons (West Indies), and tenrecs (Madagascar and Africa).

The two largest families of this order are the only representatives in North America and in this Appalachian region; the Soricidae (shrews) and the Talpidae (moles). According to the Checklist of North American Mammals, there are 34 species of shrews and 7 species of moles in North America.

There are eight species in the shrew family and three species of the mole family in this Appalachian region.

 

Family Soricidae - Shrews

ARTICLES

Shrews are small, short-legged, mouse-like animals with long, pointed noses.  Shrews are known from Eocene fossils in North America (approximately 50 million years ago), but probably have been around much longer.  These highly energetic mouse-sized mammals have beady eyes with five toes on each foot (most mice have four toes on the front feet). Shrews have soft fur that will lie either forward or backward.  Teeth of the Soricidae family have chestnut-colored tips.  Often difficult to identify (although long snouts will help differentiate between shrews and mice). Shrews constitute some of our most common mammals.  However, they usually inhabit moist areas.  This family includes the smallest terrestrial mammals in the world (the pygmy white-toothed shrew of Africa, or the Savi's pygmy shrew of the Mediterranean region, weighing no more than 1/16 ounce).  North America’s pygmy shrew is the second smallest mammal in the world.  Shrews, more primitive than rodents, have a smaller brain, and, like reptiles, many species, including the northern short-tailed and the least shrew, have both genital and urinary tracts merge into a single opening called a cloaca.   (As is often the case in nature, things aren't always simple.  The genus Sorex is has two openings, like most mammals.)  Shrews have poorly developed eyesight, but have a well-developed sense of smell, which it uses in hunt of prey.  Their small size enables them to access food sources unavailable to most mammals or birds.  Shrews are fairly vocal, with many sounds made that are above the hearing range of humans.  Like whales and bats, water shrews, wandering shrews and masked shrews utilize high frequency ultrasonic sounds for hunting, orientation, protection, and communication. The northern short-tailed shrew has poisonous neurotoxic saliva, similar to cobra venom that can paralyze or kill a mouse. Shrews are very aggressive and usually solitary, only meeting to mate. They are very nervous; known to die from fright from loud noises, even from thunder. Additionally, most species are known to exhibit post-partum estrus (females coming into heat right after giving birth)

These primitive mammals essentially do everything extremely fast. With life spans of normally a year or less, a whole "lifetime" must be condensed into basically one season. For example, shrews have extremely high energy/metabolic rates. Under stress, heart rates have been recorded as high as 1200 beats per minute. Captive short-tailed shrews have recorded heart rates of 750 at rest with a respiration of 168 breaths per minute. With the highest surface area relative to body mass of all mammals, much of the heat they generate metabolically to maintain their body temperature soon dissipates into the air.  To maintain their metabolic needs, shrews need to eat their approximate weight every day. Their high metabolic rates require frequent periods of feeding and short intervals between feedings.  To aid in this metabolic need, some species in the Sorex genus are coprophitic (they eat their feces).  With such a high metabolism and high surface area ratio, they are unable to hibernate; they would burn up too much calories and lose too much heat through their skin.  To survive cold periods, they must simply turn up the metabolism and burn more energy; a costly requirement.  Not able to hibernate, their life cycle is simply a matter of eating and reproducing before inevitable death.

Most shrews inhabit moist areas.  They frequently have markedly restricted habitats, due to their small size necessitating specific temperature and evaporation requirements.  Due to musk glands, shrews are often killed, but not eaten.  In winter, shrews, like voles, are subnivean, tunneling in snow (mice generally do not tunnel). Shrew holes, if made in the soil, are 1" diameter at most. Tracks are often squirrel-like, with the front feet parallel to the rear feet. Straddle tracks of the long-tailed shrews (Sorex) are only 1" wide with a tail track often visible, especially in snow. Tracks of the larger short-tailed shrews (Blarina) are slightly larger. Like field mice, shrews make runways in moss and vegetation, and make their dens either in their own dug tunnels or in vacated tunnels of other small rodents.  Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).  No sexual dimorphism exists among the shrews (both males and females are the same size.)  Shrews shed their set of milk teeth very early in life and are seldom functional.  (If lost later in life, they might starve to death before the new teeth can come in.)  In essence, one set lasts an entire lifetime, with “old” shrews occasionally found with their teeth worn down completely.

Shrews are generally extremely solitary with no tolerance of others of either sex, except for a short breeding period.  They must engage in complex courtship behavior to progress from aversion to copulation.  The least shrew is the exception, having a moderate level of social ties.

As is everything dealing with shrews, reproduction is a rapid event.  Copulation usually lasts ten seconds.  Gestation is three weeks.  Dispersal of young occurs in three weeks in most species.  This allows for several broods per season.

This family of 22 genera and 322 species (Nowak) is found on all continents except Australia and Antarctica and other smaller land areas.

The family Soricidae is divided into two subfamilies, with all North American shrews in the subfamily Soricinae.  These are called the red-toothed shrews because of the red or chestnut pigments on the tips of their teeth.  Twenty species from five genera are found in North America (Jones).  Nine species of shrews exist in this Appalachian region.  Three genera exist; the long-tailed shrews of the Sorex genus include seven species, while both the short-tailed shrews of the Blarina genus and the small-eared shrews of the Crytotis genus have only one representative species in the Appalachian region.  Many are boreal species, found only in cooler, higher elevations in our study area.  It has been postulated that North American shrew communities will generally include several shrews and rodents of different sizes, taking advantage of differing prey and habitats within a given area. For example, the smoky shrew lives alongside deer mice, red-backed voles, pine voles, woodland jumping mice, short-tailed shrews and hairy-tailed moles.  Such a community might also consist of three shrews, each feeding on different sized prey (short-tailed, smoky, and masked shrews feeding on large, medium and small prey).

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CINEREUS or MASKED SHREW  (Sorex cinereus)  (shrew, ash-colored)

Appalachian Region Distribution: A boreal species (northern), found along the Appalachian ridge down to about Springer Mtn.
Continental Range: Throughout Canada and northern US.  Only one subspecies exists in the Appalachian region.  
Abundance: Common, but with large annual variability. Throughout the Appalachians, especially in moist environments, it is usually the most common shrew.
Population Density: W/H reports densities vary greatly from year to year and from place to place. PA Mammals reports 1-10/acre.
Size and Molt: Head and body 2 to 2 ½ inches; 1/10 - 1/4 oz. This one does not have a masked face. One of the smallest shrews.  Two molts.
Mammae: Three pair.
Habitat: Found in most variable habitats of all shrews. Prefers moist, mature, mixed or deciduous forests.  Often found among rocks and logs in moist woods or marshy meadows and sphagnum bogs.  In WVA, it is most common about beaver dams and alder thickets and in open stands of deciduous and coniferous forests.  In the southern Appalachians, most common above 3000’ elevation.
Active Period: Active both day and night (like most shrews), but mainly nocturnal. Consumes up to it’s own body weight each day (or more - see diet below).
Diet: Insects, earthworms, other shrews, small mice, snails, slugs, and some vegetable matter. In winter, diet is mainly insect eggs and pupae, but is known to eat significant quantities of coniferous tree seeds.  Has been reported to eat three times its weight each day (but its own weight is more reasonable). 
Home Range: ¼ acre (1,200 sq. ft.) to 1 ½ acres.
Social Structure: Often gregarious (as many shrews may be), with the male often staying with the female during child-rearing.
Life Cycle: About 3 litters per year (April through October) with an average of six per litter. Gestation of 22 days, weaned in three weeks. Young leave the nest at four weeks with sexual maturity in 2 months, three months, or 5 to 6 months, depending on publication. (W/H says they don’t breed the summer of their birth, thus, a life span of 15 months is suggested.)  Life span less than one year.
Nest: 3" spherical nests of dry leaves or grass in stumps, logs, or under rocks.
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).        
Tracks: Travels and hunts in subterranean tunnels made by itself or other rodents.  Forsyth says the masked shrew does not make it’s own runways.  Straddle tracks are only 1" wide with a tail track often visible, especially in snow.

Remarks: Heartbeats and respiration have been recorded at 1200 per minute. Has been reported to eat three times its weight each day. The young exhibit a "caravaning" habit of following-the-leader in a single file line, each one with its nose in the fur of the one in front of it.  Is known to be a good swimmer. 
 

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LONG-TAILED or ROCK SHREW (Sorex dispar) (shrew mouse; dissimilar)

Appalachian Region Distribution: Throughout the higher elevations; not in the Shenandoah National Park
Continental Range: An Appalachian ridge dweller only found from Nova Scotia and southeastern New Brunswick, through Maine to SW North Carolina and eastern TN.  Two subspecies have been recognized; the separation is about the Maryland border (see remarks).
Abundance: Rare in general, but locally abundant where it is found.
Population Density: PA Mammals reports < 2 / acre.
Size and Molt: Head and body 2.4 - 2.9 inches; 1/5 - 1/4 oz. Of medium size, with a much longer tail than the other species. Two molts.
Mammae: Three pair.
Habitat: Cool, moist upland rocky habitats of two types: talus slopes, mossy rock piles, or near streams under rotting logs in deciduous or mixed deciduous/coniferous forests.
Active Period: Active day and night, year-round.
Diet: Feeds among rocks for centipedes, insects and spiders.
Home Range: Probably about an acre.
Social Structure: Solitary, and not territorial.
Life Cycle: One to three litters per year, with two to six per litter are reported.  Breeding occurs between April through August.  Life span of 12 to 18 months.
Nest: Nests in the crevasses of rocks.
Scat
: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).
Tracks: Straddle tracks are only 1" wide with a tail track often visible, especially in snow.

Remarks: Aka rock shrew.  Little is known about this species due to its subterranean habit.  It has an exceptionally long tail; about half of the total length, presumably used as a counterbalance.  The long-tailed shrew is significantly smaller in northern latitudes and larger in the southern part of its range. (The reverse of Bergmann’s Rule.)  In this study area, populations in the southern Appalachians (S. dispar blitchii) are the largest, with decreasing size noted from Pennsylvania northward (S. dispar dispar).  

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MARYLAND SHREW (Sorex fontinalis) (shrew mouse; from a spring or fountain)

Appalachian Region Distribution: This species occurs in a limited region centering on central Maryland and SE Pennsylvania.  It has also been found in northern Delaware, NE West Virginia and is probably, but not yet identified, in northern Virginia.  This is the total continental range of this questionable species (see remarks below).
Continental Distribution: It is only found in the Appalachian study area as noted above.
Abundance: Not known.
Population Density: PA Mammals reports 1-10/acre
Size and Molt: Head and body 2.1"; 0.08 - 0.16 oz.  Two molts.
Mammae:  
Three pair.
Habitat: In Pennsylvania, habitats tend to be moist, including sedge-grass meadows, woodlands, and hedgerows in early succession. A collection of 296 by Gordon Kirkland on South Mountain, near Shippensburg, PA included mature lowland forest, mid-slope oak forest, ridge forest (oak and blackgum), and oak clearcut 3-4 and 9-10 years old.  Many were also collected in the Cumberland Valley in meadow, hedgerows, and forests.
Active Period: Active year-round.
Diet: Insects, annelids, and other invertebrates.
Home Range: PA Mammals reports 0.5 to 1.5 acres
Social Structure: Presumed similar to the masked shrew.
Life Cycle: Two to three litters of four to six a year.  Breeding occurs from late February to late September in Pennsylvania.  Gestation period is 18 days.  Lives up to 18 months.
Nest: Nests are located below stumps, logs, roots and occasional white-footed mice nests.  Nests are made of grass and leaves and are similar to the masked shrew.
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).
Tracks: Presumed similar to the masked shrew.

Remarks: The above information comes from the Mammals of Pennsylvania (1987) and W/H.  Little is known about this species.  The Maryland shrew was originally described as a distinct species, but in 1911, it was relegated to a subspecies of the masked shrew, where it remained until work in the late 1970's and 80's gave it a species status, which it tenuously still maintains now, amid much technical debate.  It may be a hybrid between the masked and southeastern shrew.  The type locality is Cold Spring Swamp, Prince Georges County, MD.  

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SMOKY SHREW (Sorex fumeus) (shrew mouse; smoky)

Appalachian Region Distribution: Throughout.
Continental Range: Another mountain boreal species, from southeastern Canada west to Great Lakes and south to the Smokies and Springer Mtn. Two subspecies are recognized in the eastern US with one (S. fumeus fumeus) in this Appalachian region. 
Abundance: Locally abundant (in favored habitat). Variable in seasons.
Population Density: W/H reports 5-14/ acre, with extremes reaching 57 per acre.  PA Mammals reports 1-6/acre.
Size and Molt: Head and body 2 ½ to 3 inches; 1/5 to 1/3 oz. Two molts.
Mammae: Three pair.
Habitat: Cool, moist, shady mature birch or hemlock forests with a deep leaf layer and much fern growth. Roadside cuts that expose bare rock faces under moss-covered logs and rocks are good sites.
Active Period: Mainly nocturnal, but can be active both day and night under the leaf litter, year-round. They have been trapped at temperatures of -35 degrees.
Diet: Leaf litter inhabitants.  A New York study shows (in preference); insects, earthworms, centipedes, millipedes, snails, salamanders, and others. Will travel through tunnels and runways made by moles and voles in search of prey, thus, tend to eat more worms than most shrews.  These have never consumed more than half their weight per day in captivity.
Home Range: Probably about an acre.
Social Structure: Has been known to be gregarious in captivity.  However, normally considered to be
solitary and highly aggressive towards others.
Life Cycle: Two or three litters of five to six (2-8) per litter per year, born from April through July. Gestation of 21 days (Forsyth says two weeks), with female coming into heat right after giving birth (post-partum estrus). Young leave the nest after one month and become sexually mature after first winter. Most breeding adults will not survive the winter (their second winter).  Thus, usually only juveniles are found in winter.  Lifespan, thus, is 14 to 17 months.  
Den/Nest: Makes small baseball-sized, spherical grass/leaf nests 5 to 20 inches below the ground or in stumps, logs or among rocks.
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).        
Tracks
: Often used tunnels made by other small mammals (like moles), especially in the leaf mold, since their feet are not adapted for extensive digging (burrows have openings the size of a dime).  Straddle tracks are only 1" wide with a tail track often visible, especially in snow.

Remarks: Molts of different colors: spring molt of dull brown; fall molt of dark gray. Large predator of insects and arthropods.  Known for their echolocation abilities.

Known for its propensity to forage in leaf litter.

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PYGMY SHREW (Sorex hoyi) (shrew mouse; Dr. Philip Hoy)

Appalachian Region Distribution: The Appalachian Mountains support disjunct populations from the main Canadian population that follows the higher elevations to the Smokies.  Until recently, pygmy shrews were not known in central PA.  Also known to exist throughout Virginia and west of the Chesapeake Bay in Maryland. Although considered a northern species, they have been found in large numbers in a recently completed eight year study in the Fort Belvoir, VA area.
Continental Range: The main range of the pygmy shrew stretches from New England northward throughout Canada, with a disjunct mountain population in the Appalachians and Rockies.  Three subspecies have been described in eastern US, with two recognized in the Appalachian region, the border being Maryland.   

Abundance: Most abundant in boreal latitudes.  Little is known since they can avoid being caught by conventional traps; only pitfall traps seem to work. Assumed rare, but may be more common than known. Fewer than two dozen have been found in Virginia, Maryland, and North Carolina. There are only two records in the Smokies.  First found in PA in 1984.  Has been found at all elevations throughout VA. (In fact, the pygmy shrew has the largest distribution of all shrews in VA.)
Population Density: PA Mammals reports < 1/acre.  W/H says similar to masked shrew (
W/H reports densities vary greatly from year to year and from place to place.This species is found at lower densities than other shrews.
Size and Molt: Head and body 1.8 - 2.2 inches; 0.07 - 0.14 oz. By weight, probably the smallest mammal in the world, weighing about the same as a dime.  The smallest subspecies is the S. hoyi winnemana , whose range covers most of the southern Appalachians.  Its type locality is the banks of the Potomac River near Stubblefield Falls, 4 miles below Great Falls.  It's size averages just less than two inches (head and body) and weighs two grams, or somewhat less than a dime.  Two molts.
Mammae: Four pair, as opposed to three pair of other Sorex species.
Habitat: Diverse habitats, but generally well-drained sites, such as steep rocky slopes (birch-basswood-hemlock woods) with heavy leaf litter, rotting logs, and rhododendron shrub layer.  Also, grassy areas, such as old field and edge situations, as well as mixed forests.  Wet areas, including bogs and wet meadows, must be near.
Active Period: Active both day and night, year-round.
Diet: Insectivorous, foraging through the soil litter layer, preferring grasshoppers and
ants, but often not willing to take on a worm, due to size. Some herbivorous foods and carrion have been recorded in pygmy stomachs.
Home Range: ½ acre
Social Structure: Solitary and highly aggressive towards others.

Life Cycle: Produces one, occasionally two, summer litters per year with five to eight per litter.  Can give birth any month of the year.  One western Kentucky study found a peak from January to March and a lesser peak from August to December, with the other sympatric southeastern shrew birthing in the late spring/summer period (alternating birthing periods).  Life span of 12 to 18 months.
Den/Nests: Dens may be a burrow under a log or in old stumps.
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).        
Tracks: The pygmy shrew makes very small burrows beneath stumps, fallen logs and the leaf litter of the forest floor.  The burrows are the size of a large earthworm hole.  The holes are so small (how small are they?), that the holes are not quite large enough to admit a pencil.  Pygmy shrews have been known to enter dung beetle burrows and eat the contents. 

Remarks: The pygmy shrew approaches the theoretical minimum body size possible since mathematically, a smaller body size cannot produce as much heat as is lost by its surface area.  (Note, a recently found fossil was unearthed in some 54 million year old Wyoming limestone, which is by weight the littlest non-flying mammal ever found, in fact, smaller than thought possible.  The Batodonoides vanhouteni dwarfs the previous record holder, the Etruscan shrew, with a total body length of less than an inch long, and a lower jaw measuring less than a third of an inch long, with the largest tooth a mere three-hundredths of an inch long.)

Taxonomic classification of the pygmy shrew is still in question, with placement in either the genus Sorex, Microsorex, or other subgenus classifications.  

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SOUTHEASTERN SHREW (Sorex longirostris) (shrew mouse; ?)

Appalachian Region Distribution: A southern species, found from central Virginia west into southern West Virginia and south.  Not a common Appalachian inhabitant ; more common in piedmont and coastal plain.  Only 3 records in the Smokies.
Continental Range: Includes most of the southeastern US.  Three subspecies are currently recognized in eastern USS longirostris fischeri, found in the Dismal Swamp of VA and NC is designated as threatened by the USDI.   S. longisrostris longirostris is the only subspecies in the Appalachian region.
Abundance: Uncommon in the Appalachian Region. With little existing data, it is possible that it may be somewhat common in the preferred piedmont and coastal plain swamplands.
Population Density: One Alabama study found a density of 12-18 per acre.
Size and Molt: Head and body 1.9 - 2.7 inches; 1/8 - 1/5 oz. One of the smallest long-tailed shrews.
Mammae: Three pair.
Habitat: Found in moist or mossy habitats and early successional fields, most common in the Piedmont and Coastal Plain. Will also inhabit drier uplands.  
Active Period: Day and night, year-round.
Diet: Most invertebrates, including spiders, moth larvae, slugs and snails, daddy long-legs, beetles and centipedes.  They are also known to have munched on some vegetation.
Home Range: Similar to the masked shrew.
Social Structure:
Solitary and highly aggressive towards others.
Life Cycle: One or two litters of an average of four per litter per year, born from April to October. Young often are sexually mature by the end of their first season. Shrews probably mature, breed and die on an annual turnover basis.
Den/Nest: Burrows are pencil-sized, normally in mossy areas.  Can also be simply shallow depressions made of grasses and leaves, usually within or under decaying logs.
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).        
Track
: Spends most of their time under the leaf litter of the forest floor and in subterranean tunnels. Straddle tracks are only 1" wide with a tail track often visible, especially in snow.

Remarks:  First described by John Bachman (of Audubon and Bachman fame) in 1837, and is also known as Bachman's shrew, who discovered it in 1837.  Apparently does not overlap range of the masked shrew (the two species exhibit contiguous allopatry, as opposed to sharing common habitat – sympatry).  The short-tailed shrew is sympatric with the pygmy shrew.  The boreal masked shrew is normally found above 1500’, while the southeastern shrew is normally found below 1500”.   Due to large range, often brought home by cats, but not eaten, having strong musk glands, as all shrews.
 

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COMMON WATER SHREW (Sorex palustris) (shrew mouse; marsh)

Appalachian Region Distribution: A boreal species, found only in relic populations from the last Ice Age at high altitude along the Appalachian ridge from southern Pennsylvania south to the Smokies.
Continental Range: Throughout Canada, and protruding south through the Rockies and Appalachians. Ten subspecies are recognized in North America.  Four subspecies are recognized in the eastern US, with two in the Appalachian region (S. palustris punctulatus; the largest subspecies; whose type locality is 6 miles NW of Durbin, Shavers Fork of Cheat River, WV and S. palustris albibarbis in PA and to the north.).
Abundance: Uncommon to rare, due to restrictive habitat needs. May be locally abundant along high mountain streams
Population Density: Not known, but not as uncommon as museum collections may indicate.
Size and Molt: Head and body 3.0 - 3.8 inches; 1/3 - ½ oz. The largest of the long-tailed shrews (Sorex genus) in the Appalachians. Two molts.
Mammae: Three pair.
Habitat: Always found along banks of mountain streams of coniferous or mixed coniferous-hardwood forests (especially sphagnum moss bogs).  It readily takes to water, swimming, diving, floating, running along the bottom of a pond or creek, and actually running upon the surface of the water for some distance. 
Active Period: Active day and night, peaking at crepuscular times. Active all year.  Can reduce their metabolic demands in winter allowing them to swim underwater even under ice.
Diet: Primarily an aquatic hunter, feeding on small aquatic organisms, larvae and eggs, using its sensitive nose to feel between and under rocks.  Will eat 5 to 10% of their body weight daily.
Social Structure:
Solitary and highly aggressive towards others.
Life Cycle: Breeds from late winter well into early summer. Two or three broods per year with an average of five per brood. Gestation period of 21 days, with female coming into heat right after giving birth (post-partum estrus). Young reaches sexual maturity in three months (early season young can breed in first summer, but most wait till the following spring). Overwintering adults commonly will not survive a second winter. Life span of 18 months.
Nests: Four-inch wide nest of dried moss or twigs and leaves has been observed along bankside burrows, in or under hollow logs, under boulders or roots.
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).        
Tracks
: Straddle tracks are only 1" wide with a tail track often visible, especially in snow.

Remarks:
Powerful swimmers, foraging for aquatic invertebrates. Can dive for lengths up to a minute.  It has a fringe of stiff hairs that aids in swimming and diving.  Trapped air in the fur minimizes heat loss, but also makes the shrew buoyant, such that the shrew must paddle vigorously to stay underwater.  Are known to run across the surface of water (documented as much as five feet); its body supported by the water surface tension and trapped air bubbles in the stiff hairs of its feet, thus the vernacular "water walkers".  Since the water shrew spends so much time in the cold water, it is logical that it is the largest of the Sorex genera (a larger size conserves heat better).

The U.S. Fish and Wildlife Service is currently considering inclusion of the water shrew on their list of endangered species.  It is endangered because of siltation and pollution of the streams on which it depends and numerous other adverse human impacts on its habitat.  

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NORTHERN SHORT-TAILED SHREW (Blarina brevicauda) (coined word of unknown origin or meaning; short, tail)

Appalachian Region Distribution: A widely distributed species, occurring throughout the Appalachians, south to northern Georgia.
Continental Range: East of Great Plains, north of Georgia, to southern Canada.  Ten subspecies are recognized in eastern US (one known only on Martha's Vineyard, one only on Nantucket Island, another only in the Dismal Swamp.  Isolating mechanisms are the key here.) Basically, only two exist in the Appalachian region, separated at the VA/NC border.  A third subspecies is found in northeastern PA.
Abundance: Very common (averaging 25 per acre in good habitat)
Population Density: PA Mammals says averages from 1 to 10/acre, but quite variable, depending on habitat quality; up to 80 per acre. W/H reports a range from 1 to 50 per acre.  Population crashes are occasional.
Size and Molt: Head and body 3 ½ - 4.2"; ½ - 1 oz. (By weight, the heaviest shrew/ by length; the second largest in the Appalachian region).  Two molts.
Mammae: Three pair.
Habitat: Diverse, including moist woods with deep litter, particularly along water courses, but found throughout region in fields, thickets, and pine woods.  A semi-fossorial creature.  In fact, the most fossorial of the three genera of shrew.
Active Period: Active day and night; most active at night, year-round. Will limit its activities in winter to conserve energy.  More active on cloudy days than sunny or rainy days.
Diet: Members of the Blarina genus often feed on the minute subterranean fungus Endogone and fungi of related genera (found to constitute 4.9% of total volume of food in 1973 study).   Normally will feed on prey found in it's burrows.   Diverse, preferring earthworms (eats more earthworms than any other shrew), but also consuming insects, centipedes, millipedes, spiders, slugs, snails, mice, frogs, salamanders, minnow, crayfish, and other shrews. Forsyth states that during some periods, half of the shrew’s diet may consist of meadow voles.  In fact, Forsyth indicates vole and northern short-tailed shrew populations may fluctuate together in cycles.  Also will eat roots, berries and nuts. They also occasionally cache food, including beetles and snails.   Northern short-tailed shrews eat up to half their weight or more daily.  Winter needs are up to 43% greater than summer needs.  Up to 90% population loss in winter is possible.  Because of their energy requirements, this shrew is active for short periods (about 4.5 minutes) separated by periods of inactivity (about 24 minutes).
Home Range: ½  to 2 acres is common, with individual range overlap in non-breeding period.  Home ranges shift as prey source diminishes. 
Social Structure: Solitary and territorial, but can be kept with others of the same species in captivity.  Both resident and transient individuals exist.  Burrows are scented by males that will usually keep other males out.  NAS says mates may form unions that are more or less permanent.
Life Cycle: Normally 2 to 3 litters of an average of 6 or 7 per litter per year. Breeding begins in January or February and continues through September.  Estrus lasts 2 – 4 days.  Gestation of 21 days, weaned at three weeks, sexually mature attained at about six weeks in females and 12 weeks in males (Wilson says as early as 47 days for females).  W/H says it is probable that shrews do not breed during the season in which they are born.  Mammals of Virginia says males can breed at seven weeks, and that some early season born can mate by late summer.  Life span of usually less than a year, with captives living up to 33 months.  20 months.
Den/Nest: Burrows are less than 1" in diameter.  Two types made: a breeding nest (5"- 8" round nests of dried leaves, grasses and often fur) and a smaller resting nest; both located 6 to 16 inches below the ground in tunnels or under fallen logs and stumps. Each has several exits. Tunnel systems include separate cache rooms and latrine rooms.
Tracks: These shrews make runways in the grass or in leaf litter ½ to ¾" wide. Straddle tracks are only 1" wide with a tail track often visible, especially in snow.  Tunnels and trails of moles and voles are also used.  Piles of snail shells are notable under logs.
Scat: About one inch long, dark green and twisted, and deposited in piles near burrow entrances
.

Remarks: Note different genus; these known as short-tailed shrews. There are only three species in this genus.  Members of the Blarina genus are the only mammals in North America to have a poisonous bite. (The only other mammals equipped with poison glands are the male duck-billed platypus and the echidna.)  The poison acts on the nerves of its prey, immobilizing it for later consumption, and can cause pain for several days in humans.    Blarina species can use echolocation to locate burrow entrances, determine whether they were open or plugged, and distinguish between the different sorts of material plugging them. (Well-developed olfactory sense probably is key in hunting, not echolocation.)  Known for it’s aggressive behavior, attacking prey larger than itself. This is possible due to the poison in the saliva from a submaxillary gland in the mouth, which enters the prey, slowing the heart rate and breathing, thereby paralyzing it. The poison is both a neurotoxin and hemotoxin, much like a pit viper.  It does not inject the poison, rather, as it chews, the toxins are soaked into the wound.  Thus, insects can be cached and remain fresh for three to five days. Large insect eater due to it’s size. A common cat present, but normally not eaten due to very strong scent gland. This species is well adapted for winter survival, including a thickening of its winter pelt, ability to cache food, and restriction to the subnivean environment (under the snow). Actually hunts only 7 to 16 % of the wintertime, allowing the rest of the time for low-energy consuming activities; such as deep sleeping. Also produces layer of high energy-storing brown fat on shoulders. Recently, this species has been split from the southern short-tailed shrew (Blarina carolinensis), a lower elevation species not found in our Appalachian region.

OK, here we go.  While most shrews copulate for only a few seconds, the northern short-tailed shrew pair remain stuck together for almost half an hour.  It seems the males' erect penis bends in an S-shaped curve; fitting the females’ vagina.  The tip of the penis has a set of hooked barbs that further secures his hold on her.  Even after dismounting, they remain hooked up.  She then may drag him around backward for as long as 25 minutes.  Perhaps this prevents males from being displaced by other males.  Or, perhaps, since this awkward position makes him somewhat vulnerable to other attacks, only the biggest would subject himself to this compromising situation.

Why stop now.  It might be of interest to know that the northern short-tailed shrew’s penis can only be retracted into its storage sheath with the aid of the mouth.  Noting that mating may occur as often as 20 times, the evolutionary reason for this cumbersome arrangement is questionable, especially in light of the danger of certain external extremities getting snagged in the course of running down burrows.  It is speculated that “some form of female choice of male quality” may be operating for her benefit (and at his expense).   

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LEAST SHREW (Cryptotis parva) (hidden, ear; small)

Appalachian Region Distribution: A southern species, found throughout the Appalachian region.
Continental Range: East of Great Plains and NOT in Canada or New England. Extends south to Costa Rica.  Nine North American subspecies recognized, with four eastern subspecies recognized, and only one – C. parva parva – found in our Appalachian region.
Abundance: Common, with local populations showing large annual fluctuations.
Population Density: Nowak reports 12/acre; W/H reports 0.7/acre and 2/acre.  PA Mammals reports 1-2/acre.
Size and Molt: Head and body 2 ¼ - 2 ½"; 1/10 - 2/10 oz. Two molts.
Mammae: Three pair.
Home Range: W/H and PA Mammals report about 0.5 acres.  Other studies report a range between 1 - 3 acres.
Habitat: Unlike most species, prefers open, dry grassy areas or woods.  Also found in marshy areas (particularly, salt marshes of the coastal regions).
Active Period: Day and night (more evening or nocturnal), year-round.
Diet: Insects, spiders, snails, lepidoptera larvae, small lizards, frogs, earthworms, and carrion. Occasionally feeds on beehive larvae (thus, the vernacular, bee shrew).   Being more of an open habitat species, more lizards are part of its diet.  Is known to eat its weight in daily food (although this is thought to be uncommon), and is known to cache its food.
Social Structure: Species is gregarious and colonial, with both sexes nesting together and sharing parental responsibilities. Nests of 31 have been recorded.  Two in captivity were observed burrowing together, with one digging and the other removing dirt from the burrow and packing the tunnel walls.
Life Cycle:  2 or 3 litters per year, between March to November is the main period in the Appalachian study area, with five the average per litter. Up to four or five litters per year, any month of the year, is likely south of the Appalachians.  Gestation period of 21 days.  Weaned in 21 days, sexually mature in four to five weeks (Mammals of Virginia says 12 weeks). Exhibits post-partum estrus.  Life span of 18 months.
Den/Nest: Nests are made of grass and leaves in a globular 4-5" size under logs, stumps, flat rocks, or in burrows made by others or itself.  As mentioned above, also known as the "bee shrew" because it has been known to build its nest in beehives. 
Scat: Scats of shrews are the shape of rice grains, only smaller (1/8 – 3/16” x 1/16”).        
Tracks:  The runways are about the diameter of a pencil.  They use the runways of mice and rate and the tunnels of moles, or they construct their own tunnels, which are characteristically wider than high. 

Remarks: 18 species constitute this genus.  However, this is the only member of its genus north of Mexico.  Cryptotis has only 30 teeth, while those of Sorex and Blarina genera have 32 teeth.  Note southern range, dry, sucessional habitat, and gregarious nature that sets this species apart. The smallest of the three short-tailed shrews (including the northern and southern short-tailed shrews).  Winter grouping allows for mutual warmth-sharing, allowing a further northern range. A smaller version of the short-tailed shrew. Takes smaller prey than short-tailed shrews, foraging both day and night.  Respiration rates of 170 per minute have been recorded.   

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Family Talpidae - Moles  

ARTICLES

Moles are larger than shrews, usually with  proportionally shorter tails.  They have enlarged forefeet, reduced hind feet and pelvis and short thick fur that can be rubbed backward or forward (as it moves in its tunnels - this is due to a flat segment found near the base of each round hair). The eyes are poorly developed, to the point that they can only detect light from dark. Hearing is excellent, and the sense of smell is well-developed.  Moles are active both day and night and do not hibernate or aestivate, but will spend up to ten hours a day sleeping. Like shrews, they have a voracious appetite, feeding primarily on earthworms and other invertebrates.  Most talpids construct nest and rest chambers.

The extremely sensitive snout of the mole is unmatched in the animal kingdom.  It is covered with a dense array of nervous receptors connected to nerve cells supported by a rich supply of blood vessels.  These are organized into structures called Eimer’s organs, most outrageously developed in the star-nosed mole.  In addition, the snout, paws, tail and back of the head have sensitive bristles, like cat whiskers, that aid the mole in detecting objects. 

Moles are "fossorial" mammals; they spend practically all their lives underground. They make two types of tunnels. The pushed-up type we see are temporary feeding tubes, normally used for only a few weeks.   Most food is obtained by prey falling into the feeding tunnels, rather than excavating tunnels to find the source.   Tunnels will follow the grubs and worms (shallow in summer, deeper in winter). The second, deeper ones (down to three feet) are more permanent. These are used for sleeping, escaping from most predators and avoiding the cold of winter.  Nesting and resting chambers may be attached to these deep tunnels.  Where food supplies are favorable, generations of moles may inhabit the same tunnels. Moles will occasionally make vertical shafts to the surface to disperse excavated soil, especially in heavier, clay soil, often spreading out the soil to conceal the tunnel. In ideal soils, moles can tunnel at a rate of over 1 and ½ feet per minute.

Moles differ from shrews in several characteristics.  Moles have white teeth; not brown-tipped.  Moles have  enormously enlarged, long-clawed forefeet.  The smelling ability of moles is more limited than shrews. Star-nosed moles can be gregarious, sharing tunnels and paths with other moles (the least shrew - and the northern short-tailed to a lesser extent - is the only shrew known to be sociable).  Because of the protection afforded by the fossorial habit, only one annual litter of two to six offspring occur.  Finally, moles have molt lines, appearing as a sharp line of demarcation between old and new pelage. 

Although the eastern moles are generally solitary, the hairy-tailed and star-nosed mole may live as male-female  pairs during the winter.  The receptive period for females is only once a year, usually in early spring.  Males ensure impregnated females are exclusively mated through the formation of a plug that forms a sort of chastity belt in the females’ vagina. 

From the 17th through the 19th centuries, moleskins were used for caps, purses, tobacco pouches, and trimmings for garments.  American imported as many as 4 million moleskins a year from England.  The demand for moleskins was so great that its extinction in Germany was anticipated.  In 1959, approximately one million skins were still trapped in Britain.  Most moleskins now come from Russia.   

Moles are known from the Oligocene in North America (30 million years ago), but European fossils go back to the Eocene (50 million years ago).

Worldwide, there are 17 genera and 42 species in this family (Nowak).  

There are seven species from five genera in North America (Jones). Three species are found in our region.  

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HAIRY-TAILED MOLE (Parascalops breweri) (large, rounded forefeet that act as a shield; Dr. T. M. Brewer - zoologist)

Appalachian Region Distribution: Throughout. From Maryland south, tends to replace the Eastern Mole above 2,000 feet elevation.
Continental Range: In Appalachians, from New England, west to Great Lakes, south to Springer Mountain, GA.  The type locality is supposedly Martha's Vineyard; a place where the mole probably does not occur!  See remarks below.  No subspecies are described.
Abundance: Relatively common above 2,000 feet. Tends not to overlap lower elevation range of the eastern mole.  The most common mole of the mountains.
Population Density: 1 per acre is common, up to 11 per acre.
Size and Molt: The smallest of eastern moles.  Head and body 4 ½ to 5 ½"; 1 ½ - 2 oz . Females generally smaller than males. Two molts.
Mammae: Four pair
Habitat: Various habitats of mountains, less wet than star-nosed.  Prefers well-drained areas with sandy loam soil and a good cover of vegetation.
Active Period: Day and night, year-round, although most activity is confined to the deep tunnels during the colder season.  Feeds on the forest floor mainly at night, thus preyed upon by nocturnal predators.
Diet: Beetle larvae, worms, ants, ground-dwelling wasps and beetles. Like shrews, (and unlike other moles) will eat up to three times it’s weight in a single day.  (Stokes says one third their body weight.)
Home Range: PA Mammals reports 0.2 acre.
Social Structure:  Solitary lives except when mating time occurs in March/April, when both sexes will inhabit same tunnel systems.  Females remain near their winter ranges while males leave their winter ranges to search for mates.  Females remain solitary after mating while males freely associate in spring and share tunnels in late summer with females and young.
Life Cycle: One litter per year (sometimes two) with four to six (up to 8) per litter. Mating occurs in late March and early April.  Gestation period of  4 to 6 weeks. Young are weaned and leave the nest at four weeks. Sexually mature in ten months. Life span of 3 to 5 years.
Nest: Makes winter (8x6" dia, 16" deep), breeding (6" dia, 12" deep), and resting nests (3", along tunnels). Nests always have several exits. Winters in deeper tunnels.     
Tracks: Mole runs of rounded ridges in dry woodland soils are likely to have been made by this species.  Digs lots of shallow tunnels plus a few to 20" where a grass and leaf nest is made, having several exits. May use same tunnels for many years by successive generations. Mole hills exhibited are smaller than star-nosed mole hills. Hills are more common in fall, as moles dig for winter tunnels/nests.  Tunnels are often interconnected with those made (and used) by other moles, shrew and mice.
Scat: Cylindrical, tapered at both ends, about 1" by 1/4".  Often found in piles deposited outside the burrow.

Remarks: This is the only species in the genus.  

Most tails are black, but some have a white tip. Can damage lawns.   Along with the star-nosed mole, has 44 teeth, second only to the opossum.  Can be found with star-nosed moles, but rarely with eastern moles.

Audubon and Bachman named this species after Thomas M. Brewer, an “intelligent naturalist”, who had obtained a collection of small rodentia from New England.  This specific specimen came to Brewer from Dr. Yale, allegedly from Martha’s Vineyard. (see Continental Range comments above)  

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EASTERN MOLE (Scalopus aquaticus) (dig, foot; water dwelling)

Appalachian Region Distribution: Throughout.
Continental Range: Eastern US.  The type locality is Philadelphia, PA.  Sixteen subspecies are recognized in North America, with eight subspecies recognized in eastern US.  Two subspecies can be found in the peripheries of the Appalachian region.
Abundance: Relatively common below 2,000 feet elevation. Apparently uncommon from western and southern mountains of Appalachian region above 2,000 feet elevation. Tends not to overlap higher elevation range of hairy-tailed Mole (allopatric).  
Population Density: Unknown.
Size and Molt:  Head and body 4 ½ - 6 ½"; 3 - 5 oz.  Males are larger, on average, than females.  Northern subspecies are larger than southern subspecies.  The eastern mole exhibits the most extensive amount of geographic variation in size among the moles.  Molts twice a year.
Habitat: Everywhere, except very wet soils.  Prefers well-drained sandy soil. They spend 99% of their time underground. 
Active Period: Day and night (peak time is crepuscular), year-round.
Diet: Voracious eaters of earthworms, insects, invertebrates, including underground bees and hornets.  Eastern moles will eat an average from 31 to 55% of their body weight per day.
Home Range: 2 acres for males; 1/2 acre for females. There seems to be a great deal of overlap of male range, but not female range.
Social Structure: Solitary. Two placed in captivity have been known to fight to the death.  Each mole defends its own exclusive burrow system, although other studies show some tunnels are known to be used by several unrelated moles.
Life Cycle: Eastern moles have only one litter per year, with only three or four per litter, born in April or May. Gestation period of four to six weeks. Young are weaned and leave the nest at four weeks and are sexually mature the following spring. Life span of 3 - 4 years.
Den/Nest: Most talpids construct nest and rest chambers.  The grass and leaf-lined nest is usually 6-12" underground in a 4 - 8" chamber, with multiple entrances. Rest nests are normally smaller, but similar in construction.  Some moles used two to seven nests.  Several summer nests may be used, but apparently only one winter nest. A separate chamber is used as a latrine site.
Tracks: Makes well-known ridges as well as hills of excavated soil.  Foraging tunnels just under the surface (creating well-known surface mounds) can be dug at ten to twenty feet per hour. It has been reported that eastern moles can dig up to 100 feet of tunnel in a day.  The longest recorded tunnel was traced along a fence line for 3,300 feet.  Males construct more extensive tunnel systems than females. Makes two kinds of burrows: shallow feeding tunnels just under the soil line, with many used for foraging only once; others used frequently and may be in use for many years, and deeper (10" to 24”) tunnels that are more permanent retreats during dry or cold periods.

Remarks: This is the only species in the genus.  The misnomer species name was given by Linnaeus in 1758 based upon the description on the original collection label indicating that the specimen was found (dead) in the water (and its webbed feet). 

Highly specialized for a life underground. These "fossorial" adaptations include broad, shovel-like front paws and sealed eyelids that can only detect light from dark. Skin glands on the belly can stain it orange. Has a sensitive tail for touch. Their reproductive habits would suggest a long life, but data to support this is lacking. Moles are best controlled by trapping, not poisoning. It is important to remember that most surface tunnels are ephemeral in use, so traps must be placed on new tunnels. They have few predators, due to their isolated lifestyle, and due to their strong musk glands, like shrews, although one was found in the stomach of a Smokies copperhead. 

It is now believed that moles spend little time in actually digging tunnels.  Noting the energy spent digging tunnels, mole tunnels are used for up to eight years.  This is particularly important in hard, clay soils, which have a high density of worms and soil animals.  In loose, peaty acidic soils which are poor in food, more time is spent searching for food by digging.  Basically, when insufficient food is found, more tunnels are dug.

Nowak suggests that putting a bottle in a surface tunnel, with the opening exposed to the wind above ground, will drive away moles, due to the sound of the wind.  Chapman and Feldhamer acknowledge this, use of moth balls, and several other "home remedies" and concludes that results from such efforts are usually non-evident.  Trapping is the most common method of control.

In the 1700's and 1800's mole pelts were in demand for linings in hats, purses, pockets and other garments. Color ranges from almost black in the northern range to silver or gold in the southern races.  Have strong scent glands. Despite its undesirable trait of tunneling in turf, this insectivore’s diet of injurious insect larvae makes it exceedingly beneficial.  

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STAR-NOSED MOLE (Condylura cristata) (three processes of the tail; crested)

Appalachian Region Distribution: Throughout.
Continental Range: From the Great Lakes south along the Appalachian Mountains to Springer Mountain.  Also, a population lives in a different habitat, along the coastal seaboard into Florida.  Only two subspecies are recognized in eastern US and the Appalachian region.
Abundance: Locally abundant, but not found in all apparently suitable areas.  
Population Density: Averages about 0.8 per acre, with 16/acre possible in swamplands.  
Size and Molt: No significant sexual dimorphism, but with larger individuals typical in the northern range.  Head and body 4 to 5"; - 2 ½ oz.  Two molts.
Mammae: Four pair
Habitat: Moist, saturated soils along watercourses.
Active Period: Day and night, year-round.  Has been observed swimming under ice in winter.   Are found much more often above ground that eastern mole, especially at night.
Home Range: About 1 acre.
Diet: Worms, insects, aquatic prey, often found by probing the mud along the stream bottom (One New York study – 1931 – found aquatic annelids and aquatic insects to make up 65% of the total volume of food, with only 9.8% coming from terrestrial annelids. A Wisconsin study –1966- found earthworms to constitute 84%).  Will forage above ground in leaf litter.  In winter, often swims under ice, foraging among the stream bottom.  Due to frozen soil, will forage primarily in the water in winter.  Apparently, a deposit of fatty material is stored in the tail during the winter and spring months, which provides a reservoir of energy during the breeding period.  The highly sensitive tentacles, supplied with nerves and blood vessels “feel” for prey.  See remarks below.
Social Structure: Often gregarious, living in small colonies, but this may be more a function of food supply than social habit.  Unlike the other mole species in this Appalachian study area, the male and female may pair up in the fall and mate in the spring.
Life Cycle: After a mid-February/March mating, one litter per year (around May) occurs, with an average of five (up to 7) per litter. Gestation period of 45 days. Independent at three to four weeks, mature at ten months. Life span of 3 - 4 years.
Den/Nest: 5 - 6" spherical nests of dried leaves and grasses just below the surface, under logs or roots (but always above high water).  Similar, but smaller, resting nests are also made.  Burrow openings surrounded by excavated soil.
Tracks: Differing from the other two species of moles, the star-nosed mole alternates between subterranean and surface runways.  Tunnels are irregular and crooked.  Also has tunnels that open directly under water.  Spends more time on the surface than do the other two species. 
Will travel on snow in the winter.

Remarks: This is the only species of it's genus.  

Easy to identify due to the 22 fleshy pink appendages on the nose (containing highly sensitive tactile organs called Eimer’s organs). They are tactile receptacles. Evidence has been presented to support the hypothesis that the star-nosed mole uses an electrical sense to detect prey (presumably in water).  Has 44 teeth, second only to the 50 of the opossum. 

This semi-aquatic mole is an excellent swimmer, often foraging underwater (can stay underwater up to three minutes).  It has been seen swimming under the ice and is frequently caught in muskrat and minnow traps set in streams and lakes.

Like the hairy-tailed mole, the star-nosed mole pushes up mounds of soil up to 12 inches in diameter on surface, but it pushes the soil up from the bottom, so a central hole is never observed. Very hard to catch by mole traps due to sensitive nose appendages.  Enlargement of the tail with fatty tissues may act as a temporary reservoir for energy useful during the breeding season.  

A robust population occurs just outside of Richmond, VA.

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