he family Talpidae includes the moles, shrew moles, and desmans, all of which are confined to the north of North America and Eurasia. These predominantly burrowing insectivores (29 species in 12 genera) are highly secretive and because of their way of life have, in general, been poorly studied. The species that has, to date, received most attention from naturalists and biologists alike is the European mole (Talpa europaea), whose way of life and behavior are probably quite similar to many of the other species within this family.
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 寵物去新西蘭 the permanent habitation of the resident animal, acts as a food trap constantly collecting invertebrate prey such as earthworms and insect larvae. As they move through the soil column invertebrates fall into the animal’s burrow and often do not escape before being detected by the vigilant, patrolling resident mole.Once prey is detected, it is rapidly seized and, in the case of an earthworm, decapitated. The worm is then pulled forward through the claws on the forefeet, thereby squeezing out any grit and sand from the worm’s body that would otherwise cause severe tooth wear-one of the common causes of death in moles.
How Do Moles Construct Tunnels?
Tunnel construction and maintenance occupy much of a mole’s active time. A mole digs actively, throughout the year, although once it has established its burrow system, there may be little evidence above ground of the mole’s presence. Moles construct a complex system of burrows, which are usually multi-tiered. When a mole begins to excavate a tunnel system. It usually makes an initial relatively straight exploratory tunnel for up to 20 meters (22 yards) before adding any side branches. This is presumably an attempt to locate neighboring animals, while at the same time forming a food trap for later use. The tunnels are later lengthened and many more are formed beneath these preliminary burrows. This tiered- tunnel system can result in the burrows of one animal overlying those of its neighbors without them actually being joined together In an established population, however, many tunnels between neighboring animals are connected.
Mole’s Sense of Navigation
Moles have a keen sense of orientation and often construct their tunnels in exactly the same place every year.In permanent pastures, existing tunnels may be used by many generation of moles. Some animals may be evicted from their own tunnels by the invasion of a stronger animal and, on such occasions, the loser will have to go away and establish a new tunnel system.These master engineers are highly familiar with each part of their own territory and are suspicious of any changes to a tunnel, which makes them difficult to capture. If, for example, the normal route to the nest or feeding area is blocked off, a mole will dig either around or under the obstacle, rejoining the original tunnel with minimum digging.
Our knowledge of the sensory world of moles is very limited. They are among the exclusively fossorial species, the eyes are small and concealed by dense fur or, as in the blind mole Talpa caeca, covered by skin Shrew moles, however, forage not only in tunnels beneath the ground but also above ground among leal litter Although they may have a keener sense of vision than other species they are still probably only able to perceive shadows rather than rely heavily on vision for detecting prey or for purposes of orientation.The apparent absence of ears on almost all species is due to the lack of external ear flaps and the covering of thick fur over the ear opening. It has, however, been suggested thar ultrasonics may be an important means of communication among fossorial and nocturnal species. But of all the sensory means olfaction appears to be the most important medium-a fact supported by the elaborate nasal region of many species, together with the battalion of sensory organs stored within this area.