While post people consider them pests, burrowing animals perform this behavior for a number of different reasons. Burrows serve as habitats, ways of locomotion and larders, where animals keep their food. Burrowing behaviors are crucial for certain animals to survive and more animals then you would expect actually burrow. This behavior has been around for millions of years, with one of the first burrows being one of a dinosaur species on the south eastern coast which is now known as Australia.
Invertebrates, vertebrates, mammals and marine animals burrow.
Examples of Invertebrates that burrow:
- Sea Urchins
Examples of Vertebrates that burrow:
There are many more in both categories, but this shows that burrowing behavior is very common across the animal kingdom.
Burrowing for Habitat
Within different habitats, for example the desert, temperature needs to be a degree in which animals can withstand. This is why many desert animals burrow, whether it be in the ground or in a cactus like the Gila Woodpecker.
Safety and protection is another main reason animals live in burrowed habitats. These habitats are all different, ranging from small holes to long tubes stretching for miles. They can be simple or elaborate channels that connect from multiple different areas. Moles for example, can tunnel 20m per day. These animals typically burrow in grass or farmlands and need deep enough soil to tunnel through. They use these tunnels for nesting when they are not on the move. Another type of mole, the Southern Marsupial Mole found in the desert of Australia, do not make permanent tunnels like other species do. When they dig tunnels through the sand, the sand caves back in and fills the tunnel behind them. These species of mole usually tunnel horizontally and at shallow angles, but sometimes for no reason they will suddenly burrow vertically to depths up to 2.5 meters. In regards to temperature mentioned above, moles can select the temperature of their environment at different depths. Ground hogs are also long tunnel burrowers, digging up to 46 feet of tunnels underground. When they dig these tunnels they can move up to 35 feet of soil. They have multiple areas of entrance to these tunnels, which makes it frustrating to some people when they have many holes popping up out of their yard.
In some animal species, burrows are a place for parents and offspring to live. An example of these burrows would be a beaver dam, in which a complex habitat is built that provides them with protection. There is an underwater entrance to their dens and gives them access to their food supply. Families of beavers may also build and burrow several different habitats in the surrounding area. Bank dens are dug into the sides of banks and streams and typically used in the winter.
The above photo shows an animation of an underwater burrow beavers have made as an entrance point to their lodge. Similar to full family burrows, maternity dens are also made for the pregnant mother to give birth to her offspring. These burrows are commonly used for species of bear and others.
Burrows can be made from:
The most common surface burrows are made from is soil, in which groundhogs, moles and birds use for burrows. Wood is another surface that termites use to burrow. Termites burrow through living and fallen wood. Sand is also used for burrowing and mentioned previously. Skin of animals and humans can be used for burrowing with species such as scabies mites.
Some animals would rather use the burrows made by other animals then build their own. An animals species that displays this behavior is the meerkat, and the burrows they use are built usually by squirrels or mongooses. Sometimes colonies of meerkats actually share the burrows with other animal species. They have also been known for sharing burrows with species of snakes. Similarly to groundhog burrows, they use as many as 90 entrances to their burrows. The meerkats only leave their burrows during the day, while one individual stands guard looking for predators. If they spot a predator they will give a warning bark to the rest of the colony. This is an example of altruistic behavior displayed by the individual because it puts them at risk of being noticed by the predator.
Can Burrows Cause Harm to the Environment?
Burrowing has evolved and been adapted to many animals for many different reasons. But these burrows can actually harm the environment. When colonies of soil digging animals such as groundhogs take over large stretches of land, they can destroy plant life and leave bare dirt. This makes the land more vulnerable to flooding and erosion. An ideal location for prairie dog burrows is large grasslands, which are also where live stock graze. This poses problems to the livestock such as lack of plant life to eat. Prairie dogs also attract predators such as bobcats and coyotes, which also can be threatening to livestock like sheep.
Here are some videos of above animals displaying burrowing behavior: