The family Talpidae includes moles, shrew moles, and desmans, all of which are confined to northern North America and Eurasia. These predominantly burrowing insectivores (29 species in 12 genera) are very secretive and, due to their way of life, have generally been poorly studied. The species that, to date, has received the most attention from naturalists and biologists alike is the European mole. (European Talpa)whose way of life and behavior is probably quite similar to many of the other species within this family.

Moles are highly specialized for a subterranean and fossorial way of life. Its broad, shovel-shaped forelimbs, which have developed into powerful digging organs, are attached to muscular shoulders and a deep thorax. The skin on the chest is thicker than on other parts of the body, as this region bears most of the weight of the mole when it burrows or sleeps. Behind the massive shoulders, the body is nearly cylindrical, tapering slightly to narrow hips with short, stocky hind legs (not particularly adapted for digging) and a short, club-shaped tail, which is usually carried erect.

In most species, both pairs of limbs have an additional bone that increases the surface area of ​​the legs, for additional support on the hind legs, and for moving the earth with the front legs. The elongated head tapers to a pink, fleshy, hairless snout that is highly sensory. In the North American star-nosed mole (Condylura cristata)this organ has 22 tentacles, each of which has thousands of sensory organs.

How do moles dig burrows?

The function of a mole’s burrow is often misunderstood. Moles do not dig constantly or specifically for food. Instead, the tunnel system, which is the permanent habitation of the resident animal, acts as a food trap that constantly collects invertebrate prey such as earthworms and insect larvae. As they move through the soil column, the invertebrates fall into the animal’s burrow and often do not escape before being detected by the resident mole that watches and patrols.

Once prey is detected, it is quickly captured and, in the case of an earthworm, decapitated. The worm is then pushed forward through the claws of the forelegs, thus squeezing out any grit and grit from the worm’s body that would otherwise cause severe tooth wear, one of the common causes of death in moles. .

If a mole detects a sudden abundance of prey, it will try to capture as many animals as possible, storing them in a centralized hideout, which will usually be well defended. This cache, often located near the mole’s only nest, is packed into the ground so that the earthworms remain alive but usually dormant for several months. body reserves to search for scarce prey. In selecting such prey for the store, moles appear to be highly selective, generally choosing only the largest prey available.

How do moles build tunnels?

Building and maintaining tunnels take up much of a mole’s active time. A mole actively burrows throughout the year, although once it has established its burrow system, there may be little above-ground evidence of the mole’s presence. Moles build a complex system of burrows, which often have several levels. When a mole begins to dig a tunnel system. It typically makes a relatively straight initial scout tunnel up to 20 meters (22 yards) before adding any side branches. Presumably, this is an attempt to locate neighboring animals, while at the same time forming a food trap for later use. Subsequently, the tunnels lengthen and many more form below these preliminary burrows. This system of stepped tunnels can result in one animal’s burrows overlapping those of its neighbors without actually joining. However, in an established population, many tunnels between neighboring animals are connected.

Mole’s sense of navigation

Moles have a keen sense of direction and often build their tunnels in exactly the same place every year.

In permanent pastures, existing tunnels can be used by many generations of moles. Some animals can be dislodged from their own tunnels by the invasion of a stronger animal and on such occasions the loser will have to leave and establish a new tunnel system.

These Master Engineers are very familiar with every part of their own territory and are suspicious of any changes in a tunnel, making them difficult to capture. If, for example, the normal route to the nest or feeding area is blocked, a mole will burrow around or under the obstacle and join the original tunnel with minimal excavation.

Our knowledge of the sensory world of moles is very limited. They are among the exclusively fossorial species, the the eyes are small and hidden by dense fur or, as in the blind mole Talpa caeca, covered by skin. However, shrew moles feed not only in underground tunnels but also on the surface among leaf litter Although they may have a keener sense of sight than other species they can probably only perceive shadows rather than rely heavily on vision to detect prey or to navigate.

The apparent absence of ears in almost all species is due to the lack of external ear flaps and the covering of thick fur over the ear opening. However, it has been suggested that ultrasound may be an important means of communication between fossorial and nocturnal species. But of all the sensory media, smell appears to be the most important, a fact supported by the elaborate nasal region of many species, along with the battalion of sensory organs stored within this area.

Breeding season

The short breeding season is a hectic time for moles, as females are receptive for only 24 to 48 hours. During this time, males often abandon their normal pattern of behavior and activity, spending large amounts of time and energy locating potential mates. Mating takes place within the female’s burrow system and this is the only period of non-aggression between the sexes.

The young, with an average of three per litter, are born in the nest four weeks later. Weighing less than 4 grams (ounce), pink and naked babies cannot control their body temperature and rely on warmth from their mother. The young feed entirely on milk for the first month, during which they rapidly gain weight. The juveniles remain in the nest until they are about five weeks old, at which point they begin a brief exploratory foray into the vicinity of the nest chamber. Shortly thereafter, they accompany their mother on further explorations of the outer burrow system and may disperse of their own volition, those that do not leave soon being evicted by the mother.