Bats emerge at sunset
Bats emerge at sunset Bats emerge at sunset © Robert and Linda Mitchell

Places We Protect

Crabtree Cave

Maryland/DC

The largest bat hibernaculum in Maryland.

Overview

Crabtree Cave is a world that exists without the light of the sun.  Its unusual habitat and unique species have evolved to survive in the permanent darkness.

All animals that live permanently within the cave, such as the nationally-rare Franz’s cave amphipod (Stygobromus franzi) and Franz’s cave isopod (Caecidotea franzi) - both aquatic invertebrates - have lost their sight and pigment. They have also acquired behavioral, metabolic, and reproductive adaptations that differ markedly from their surface-dwelling relatives.

Crabtree Cave is the largest bat hibernaculum in Maryland, and shelters eastern pipistrel, little brown, big brown, northern long-eared and Keen’s bats.

Unique Habitat

Isolated from weather, natural disturbances, and sunlight, caves have evolved their own distinctive and highly fragile ecosystems. The animals occupying caves have solved the problem of survival in these dark, nutrient-poor environments in two ways.

Some, including bats and wood rats, inhabit caves by day but return to the surface to forage at night. Others, the true troglodites (cave-dwelling animals), have adapted so completely to the special conditions that they cannot survive outside. 

Cave Management

This cave, along with John Friend Cave, is a site that includes species of incredible and fascinating, rarity. Management strategies at this 48-acre preserve focus on maintaining the cave gate to prevent unauthorized visitors and to protect the animals living in the cave. The importance of maintaining the gate has increased since the establishment of white-nose syndrome in the cave’s bat population. 

The cave is an ecologically fragile and potentially dangerous environment.  It has been closed to the public due to concerns about transmission of white-nosed syndrome, a fungal disease that is devastating populations of bats throughout the area. Thank you for your understanding and help in protecting this important part of Maryland’s natural heritage.