||The Mammals of Texas -
Insectivora : Family Talpidae :
Scalopus aquaticus (Linnaeus)
Description. A relatively small, robust,
burrowing mammal with broadened, shovel-like front feet
webbed to base of claws; no visible eyes or ears;
sharp-pointed nose; plushlike fur; and short, sparsely
haired tail. Dental formula: I 3/2, C 1/0, Pm 3/3, M 3/3
X 2 = 36; middle upper incisors enlarged; canines small
and undifferentiated; molars with W-shaped outline when
viewed from biting surface. Color brown, often with
silvery sheen, with suffusion of orange on nose and
wrists; underparts silvery gray, faintly washed with
orange. External measurements average: total length, 165
mm; tail, 29 mm; hind foot, 22 mm. Weight, 60-90 g.
Distribution in Texas. Eastern two-thirds
of the state, including eastern portions of South Texas.
In northern Panhandle extends to New Mexico line along
Canadian River drainage. Isolated record from Presidio
Habits. Moles spend most of
their life in underground burrows they excavate for
themselves or usurp from other mammals, particularly
pocket gophers (genus Geomys). Because of this,
they are restricted in their distribution by the nature
of the soil. In Texas, they occur largely in moist (not
wet), sandy soils. Deep, dry sands and heavy clays are
Two types of underground burrows are
used: (1) the shallow surface run, which is associated
with food-getting activities, and (2) the deep burrow for
protection and rearing of the young. The deep burrow is
marked by conical mounds of earth the occupant has pushed
to the surface, whereas the shallow burrow is marked by a
meandering ridge of earth pushed up by the mole as it
"swims" through the loose topsoil. Moist,
well-drained fence rows, terraces, lawns, and knolls rich
in organic matter are favored areas for surface burrows
because in these localities food is more abundant.
Certain of the surface burrows are used frequently as
highways; others, especially intricate side branches, are
used but once in the food-getting process and are then
allowed to collapse.
Moles cannot see and spend almost all
of their time underground. They may be found active at
any hour of the day but generally are more active by day
than by night in response to the movement of earthworms
in and out of the soil. Also, they are active throughout
The mole excavates its burrow by
backward strokes and lateral thrusts of the front feet.
Loose earth is moved and pushed to the surface by thrusts
of the front feet. In excavating shallow runs the earth
is merely pushed up to form a ridge, again by lateral
thrusts of the front feet while the mole is turned partly
on its side.
The home range of individual moles
consists of several "hunting grounds" galleried
with surface burrows on knolls, terraces, or along fence
rows all of them connected by a single long
burrow. One burrow along a fence row in Van Zandt County
was 360 m long. Such systems may be in continual use for
as long as 5 years, either by one mole or by successive
occupants. At times, moles travel overland in search of
new locations or, perhaps, of mates. This is evidenced by
the occasional appearance of dead moles on the highways.
Throughout most of the year moles are
solitary but in late winter and early spring males seek
out females. In south-central Texas, the breeding season
begins in February, as evidenced by the large testes of
males and the swollen uteri of females. Although the
breeding period may last from 3-4 months, peak activity
occurs in a short period of 3-4 weeks. A single litter of
two to five young is produced each year. The gestation
period is about 4-6 weeks. The young are born hairless,
but otherwise are miniature adults. Females reach sexual
maturity in 1 year.
Moles feed largely on earthworms and
grubs, although beetles, spiders, centipedes, insect
larvae and pupae, and vegetable matter may also be eaten.
In captivity, they have consumed mice, small birds, and
The average daily food consumption is
about 32% of the body weight of the animal, although a
mole can consume more than 66% of its body weight in 18
hours. Active prey is killed by crushing it against the
sides of the burrow with the front feet or by piling
loose earth on the victim and biting it while thus held.
Captive moles kill earthworms by biting them rapidly in
several places, often nearly cutting the worm in two.
Moles do damage by their burrowing
activities, especially on the greens of golf courses, in
lawns, and in situations where accelerated soil erosion
may result. Also, they may destroy row crops by burrowing
along a row and killing the plants. It must be kept in
mind, however, that the mole usually is searching out
animal food and that often the larval insects taken do
far more actual damage to the vegetation than does the
mole. Larval June beetles, for example, feed on the roots
of grasses and may, if present in large numbers,
completely destroy the sod in an area. The burrowing
activities of the mole also tend to aerate the soil, with
beneficial results to plants.
Photo credit: John L. Tveten.