Mammoth Cave National Park in Kentucky is home to a wide variety of wildlife, both above and below ground, including 70 species listed as threatened or endangered. Most commonly-seen above ground are squirrels, and deer. Rarer sightings include coyotes, black bears, and 13 species of bats -  8 or 9 species of which live within the cave. Below ground live some 160 species ranging from cave crickets to pale, eyeless fish, to translucent crayfish, to salamanders.

Before looking at some of the more unique wildlife found living within and/or near the cave, it’s important to note three different categories into which wildlife found within caves are placed.

According to park staff:

Trogloxenes - in Greek, troglos means cave, and xenos means guest. Trogloxenes come and go from caves, they typically use cave habitats as hibernation, nesting, or birthing spots. They are not adapted to spending long amounts of time in the cave, nor will they spend their entire lives in the darkness. Bats and moths are trogloxenes.

Troglophiles - troglos meaning cave, and phileo refers to love. These organisms prefer to live inside a cave but may leave the cave to search for food, a cleaner habitat, or to mate. Crustaceans like crayfish are an example of a troglophile, they can live their entire lives inside or outside a cave system.

Troglobites - troglos for cave, and bios for life. Troglobites spend their entire life cycle in caves. They only live in underground habitats, adapted to survive in total darkness. Troglobites have depigmentation, a decrease or total loss of eyesight, a slow metabolism, and are able to efficiently digest and consume food. Troglobites cannot survive on the surface nor travel between cave systems, typically they are endemic to a single cave or a single cave system. The endangered Kentucky cave shrimp is an example of a troglobite.

Cave salamander, also called the spotted-tail salamander, Mammoth Cave National Park / NPS file

An example of a trogloxene is the cave salamander (Eurycea lucifuga), often called spotted-tail salamander. These beautiful, bright orange salamanders with black spots cling to rock walls, tending to be found near the cave’s entrance, near surface water sources, or under moist rocks or logs. Cave salamanders are found in karst areas of the southern U.S., including Kentucky, Tennessee, Alabama, and Virginia. They range in length from 4 – 8 inches (10 – 20 cm), with their tail taking up most of that length. These salamanders are lungless, getting their oxygen through the skin and mucous membranes of their mouths and throats, which need to remain moist in order to absorb the oxygen. So, if you are fortunate enough to spot one on a cave wall or near water, they will look wet and even slimy.

The Kentucky cave shrimp, Mammoth Cave National Park / USFWS

The Kentucky cave shrimp (Palaemonias ganteri) and Mammoth Cave crayfish (Orconectes pellucidus) are crustaceans living either solely within the cave, or spending time both in cave and above-ground environments.

According to park staff:

The endangered Kentucky cave shrimp is found nowhere on Earth except for in the large, base level cave streams that flow through Mammoth Cave. They prefer streams with a slow flow, plenty of organic material, and with coarse, sandy bottoms. These tiny crustaceans will eat algal cells, fungi, and protozoans that are washed in by floodwaters. They are troglobites, spending their entire life cycle in the cave.

Cave shrimp are specially adapted for this subterranean life, as they have no eyes, and are able to use their two pairs of antennules to taste, touch, and smell their food. They also have no pigment in their shell, making them transparent and incredibly hard to spot. They grow to about 1.25 inches long and are estimated to live for about 10-15 years.

Mammoth Cave crayfish also have no eyes or pigmentation, but as troglophiles, they are able to move over land to different pools and streams in order to find food, mates, or to avoid predators. Normally found in cave streams, these crayfish typically hide under rocks or in sediment and can be seen scurrying across the rocky and sandy bottoms of stream beds. They have no eyes and no pigmentation, which is an evolutionary adaptation that allows them to conserve energy and survive in an environment with total darkness. They depend on the surface water runoff for food and nutrients, while bat guano and cricket droppings also provide sustenance for subterranean life. They lay eggs and are sensitive to environmental changes on the surface, like pollution, which may alter groundwater quality.

Two species of rare, cave-dwelling eyeless fish call the waterways flowing through Mammoth Cave their home. The northern cavefish (Amblyopsis spelaea) and the southern cavefish (Typhlichthys subterraneous) have adapted to a lightless environment where the waters flow languidly. There is no need for eyes to see, or skin pigment to camouflage them. They spend their entire life cycles in Mammoth Cave, their survival depending upon the quality of surface and groundwater flowing down to and through the cave’s passages.

The southern cavefish is a little smaller, growing to 3.5 inches (8.9 cm), while the northern cavefish grows to 4-5 inches (10-13 cm). The southern cavefish is unpigmented, but if taken to the surface and exposed to light, some coloration will occur. The northern cavefish are white-clear in color.

Mammoth Cave fish fact: At one point, guides at Mammoth Cave would catch and sell these eyeless fish to visitors as a novelty.

During a tour of Mammoth Cave, you might come across a common cave cricket (Hadenoecus subterraneus).

According to park staff:

Cave crickets are often found in the “twilight zone” near cave entrances but can also be found at further depths. They use their long antennae to feel what is around them both in terms of rock surfaces and in terms of air flow, which can be used to indicate the direction of an entrance. These insects are troglophiles, meaning that while they prefer cave environments they can also survive on the surface.

Two other species of cave crickets that can be found in the cave are Ceuthophilus stygius and Ceuthophilus latens. They are generally surface dwellers that retreat to the cave for protection during colder and drier conditions.

Common cave cricket, Mammoth Cave National Park / NPS file

When you think of caves, are bats the first wildlife to come to mind? Thirteen species of bats live within the boundary of Mammoth Cave National Park, but only eight or nine species live within the cave, and this is usually during maternity or winter hibernation times. Most bats in the park live in trees and structures such as bridges and buildings across the park and rarely go into caves.  Three bat species are listed as threatened or endangered:

Indiana bat (endangered)
gray bat (endangered)
northern long-eared bat (threatened)

White-nose syndrome (WNS) is a fungal disease killing bats in North America. Research indicates that the WNS causing fungus, Pseudogymnoascus destructans, is likely exotic, introduced from Europe. WNS was first detected at Mammoth Cave in 2012 and the park implemented strict WNS protocol for all people entering the cave to try to slow down the spread of this fatal disease. Due to the presence of this disease, some bat species have seen population declines and mortality rates over 90% and scientists predict some regional extinction of bat species will occur.

So, when you take a tour through Mammoth Cave, you’ll be required to walk on bio-security mats immediately following the conclusion of your tour. No exceptions.

If you are interested in knowing about the documented wildlife species within the park, click here to generate and view the species list as a PDF or to download as a csv file.