Burrow(redirected from Burrowing animals)
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a temporary or permanent shelter constructed by an animal in soil or, more rarely, solid rock; in the wood or the bark of trees; or in the bottom of bodies of water. Burrows provide protection against predators and shelter against bad weather (a relatively constant and favorable microclimate is created in them); they are used for storing food and for reproduction and raising of young. Primary (nesting) burrows often perform all these functions, while auxiliary burrows perform just one function.
The primary burrows of mammals are usually connected with auxiliary burrows by paths leading to feeding areas and to above-ground shelters. The complex burrows of marmots, gerbils, microtines, and other rodents consist of tunnels and chambers for nests and food supplies. They can be as deep as 5–7 m and have from several dozen to hundreds of entrances. The burrows of many animals (large rodents, arctic foxes, and common foxes) are renovated and altered from generation to generation and may last hundreds or even thousands of years. Such adaptation of the place of habitation to the needs of the inhabitants, constantly maintained by an uninterrupted line of generations, is an important element in the life of a species.
The burrows of amphibians, reptiles, and birds are simple and small, often nothing more than mere depressions in the ground. The burrows of invertebrates (worms and insects) are equally simple. The complex systems of passageways made by insects that are wood pests serve the purpose of feeding tunnels.
In loose soil or ground litter, animals (worms, insects, and insect larvae) make passages by moving particles of soil with their bodies, “mining” the ground. In solid ground, they use their claws (talpids and sokhors) or break up the substrate with their beaks (bank swallows and bee-eaters). Some animals use their jaws to break up the earth and gnaw out the burrow; this is typical of many insects (various wasps and bees) and those mammals (mole rats, mole voles, and jerboas) whose incisors protrude out of the mouth and are very powerful. Pholadid mollusks bore through rock by secreting an acid that breaks down the rock.
Burrows, especially complex ones, are sometimes shared by the owners with many other animals. For example, more than 200 species of myriopods, mites, ticks, fleas, true lice, and other cohabitants live in the burrows of great gerbils in the deserts of Middle Asia. During hot and cold seasons, snakes, lizards, tortoises, and turtles take refuge in other animals’ burrows. Some birds, for example, wheatears and various sheldrakes, including the ruddy sheldrake, nest in the burrows of other animals. Hedgehogs and shrews live in burrows they do not build themselves.
The complex biocenosis of a burrow may ensure the prolonged existence of the agents of dangerous diseases (the plague, leishmaniases, spirochetoses, and others); as a result, an area where there are many such burrows becomes a stable natural seat of these diseases.
REFERENCESNaumov, N. P. Ekologiia zhivotnykh, 2nd ed. Moscow, 1963.
Pavlovskii, E. N. Prirodnaia ochagovost’ transmissivnykh boleznei. Moscow-Leningrad, 1964.
Dinesman, L. G. Izuchenie istorii biogeotsenozov po noram zhivotnykh. Moscow, 1968.
N. P. NAUMOV