Mexican free-tailed bats at Eckert James River Bat Cave Preserve
Eckert James River Bat Cave Mexican free-tailed bat emergence © Rich Kostecke/The Nature Conservancy

Places We Protect

Eckert James River Bat Cave Preserve

Texas

The Eckert James River Bat Cave is one of the largest bat nurseries in the country.

Southwest of the town of Mason near State Highway 29 in Mason County sits the Eckert James River Bat Cave Preserve—one of the largest bat nurseries in the country. About 4 million female bats inhabit the site from May through September. Most of these are pregnant when they arrive. In the Bat Cave, females give birth to a single pup in June or July. The young bats grow rapidly and are able to fly at about five weeks of age. However, they will remain with their mothers until they return to Mexico in October.

An hour or two before sunset, hundreds of bats flutter and chirp around the mouth of the cave. Slowly, a stream of bats emerges and flies in a large circle, low to the ground, just outside the cave entrance. These bats gradually spiral upwards and form a dark funnel of flying mammals, reaching several hundred feet into the evening sky. The bats at the top of the spiral break off, forming columns that stream out over the countryside. This seemingly impossible torrent of bats forms a densely packed "bat tornado" for about an hour.

Millions of Mexican free-tailed bats can be seen here. Like all bat species, the free-tailed population at the Bat Cave is an integral part of regional ecology. For many years, however, bats were considered menacing creatures to be avoided or destroyed. Thanks to the work of biologists and groups like Bat Conservation International and The Nature Conservancy, this groundless reputation is slowly being corrected.

Bats are finally gaining recognition for their important ecological roles. They are agents of seed dispersal and cross-pollination for many plant species. Bats also control insect populations. They scour thousands of acres of countryside each night searching for food. During these nightly excursions, each bat consumes close to its body weight in insects. Included in their diet are mosquitoes and numerous crop pests such as cutworm and corn borer moths.

This unique preserve is home to one of the largest aggregations of warm-blooded animals in the world. Because these and other bat species roost in such large numbers, colonies could be destroyed by a single act of vandalism. The free-tailed bat population has declined dramatically in some areas of the country. This decrease is largely attributed to the disturbance and destruction of roost sites by humans, usually leading either to total evacuation of the roost or complete decimation of the site's entire population. Because free-tailed bats give birth to only a single pup each year, a population's recovery rate is slow.

Richard Phillip Eckert and Virginia Eckert Garrett donated the cave to The Nature Conservancy in honor of their father, Lee Eckert, and grandfather, W. Phillip Eckert. The Eckert family acquired the property in 1907 when W. Phillip purchased the ranch on which the cave was located. In the early 1900s, W. Phillip mined the bat guano in the cave and sold it to local farmers for crop fertilizer. W. Phillip's son, Lee Eckert, continued his father's legacy of bat conservation and guano mining and left the site to his wife and children when he passed away in 1967.

This generation of Eckerts wanted to ensure permanent protection of the bats, so in 1990 they donated the cave to the Conservancy on condition that the land around the cave remain open to the public for enjoyment and education, as it had been for more than 100 years.

The management plan developed by Bat Conservation International and The Nature Conservancy prevents human entrance to the cave during maternal activity, controls visitation, monitors the bat population and protects the cave opening. Scientific research continues at the site and the cave remains open to scientists throughout most of the year.

The preserve is open from mid-May to late in September for interpretive tours. These tours run Thursday-Sunday, from 6 p.m.- 9 p.m. Some sunrise viewings of the bats returning from their nocturnal hunts also are offered.

The preserve is open to visitors each summer. There is a $5 entrance fee. Children 5 and under are free.

For more information, call (325) 347-5970 during the season or (512) 263-8878 otherwise.