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The Mammals of Texas -
Online Edition Eastern Mole
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 avoided. 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 year. 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 ground beef. 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. |
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.