Caves are a unique, dark, bleak habitat, with a surprisingly large diversity of both aquatic and terrestrial animals living in them.
Caves, sculpted by groundwater millions of years ago, are a dark, bleak habitat with peculiar inhabitants. What kind of creatures live in caves? A surprisingly large diversity of animals both aquatic and terrestrial spend their lives in caves, if not all the time, part of the time. The temperature in caves is a fairly constant 55-58 degrees Fahrenheit. The entrance to the cave is called the entrance zone. This area of the cave is often used by birds. They use the mouth of the cave as protection from the weather, and some birds like vultures sometimes raise their chicks there.
Snakes also use the entrance to the cave, especially in hot summer months. The cooler air helps a snake’s body temperature, but they don’t usually venture farther into the cave, for there is little food there. Salamanders can also be found in the entrance area, but they also
live on the outside.
The leaf litter that blows into caves may house small millipedes, centipedes, terrestrial isopods, terrestrial snails, earthworms and various insects. Flies and mosquitoes move into the deeper parts of the cave during the winter.
As you move deeper into the cave, where there is much less light, fewer animals can be found. Bedrock fossils such as coral, sea lilies and brachiopods are present on the walls of the caves. These fossils were once inhabitants of oceans. The animals died and fell to the ocean floor, millions of years ago, eventually becoming a part of the limestone or dolomite bedrock in the cave. Black bears often use caves to hibernate in.
Of course, bats live in caves. But not all bats. Only certain bats use the cave exclusively, either roosting singly, or in dense clusters with several hundred bats per square foot of the cluster. Some bat species live in caves only during the summer, some during the winter. But some live in caves all year. Bat droppings, called guano piles, are a nutrient source for bacteria, fungi and some small animals in the caves.
Some caves contain streams and pools. Here, salamanders flourish and the pickerel frog overwinters. Other creatures like aquatic isopods, small flatworms called planaria, crayfish, aquatic snails, fish and amphipods live in the water.
Animals in the deeper part of the cave are often pink or white. These creatures are cave adapted that have been isolated from the surface for thousands of years. As a result, they have lost the ability to produce pigment in their skin, and the ability to produce eyes. These cave-adapted creatures have more developed senses because they lack eyes. Their legs and antennae are much longer, and their metabolism is adapted to the nutrient-poor environment of the cave.
Cave dwellers are grouped into three categories. Troglobites are creatures that could not survive outside of the cave. They include white and blind cavefish, millipedes, crayfish, isopods, amphipods and planaria.
Troglophiles are the cave dwellers that live both inside and outside the caves. Most salamanders fall into this category.
Trogloxenes are the third group. These are creatures that use the cave for hibernation, or roost in the caves at night or during the day, but they need to go outside the cave for their food. Bats and cave crickets fall into this category.
Cave life is vulnerable to many kinds of problems, and is a protected habitat, with peculiar inhabitants. Caves are considered a precious natural resource.