Protecting a high-flying nature act in New Mexico
Thu, Nov 10 2011 at 1:01 PM
By The Nature Conservancy
The Jornada Bat Caves, located in southern New Mexico, is the Mexican free-tail bat capital of the state.
Only five or so cave complexes across the U.S. host larger populations of this bat species (the largest is in Texas). The Mexican free-tail bats occupy the caves from March through October, with a maternal colony of well over 100,000.
And, they are not alone.
Seven other species of bats have been identified at the Jornada site, including Allen’s big-eared bat and the spotted bat. In addition, millions of migratory bats use the cave as a stop-over site during the warm season.
Talk about tight quarters!
Despite these staggering numbers, bat populations around the world are experiencing dramatic declines.
For example, it has been estimated that the population of Mexican free-tailed bats in Carlsbad Caverns once numbered in the millions — today those numbers are under 500,000.
Why should we care?
Bats are essential to the health of our natural world. Losing them would have devastating consequences for nature and the economy. Here a few ways bats benefit us:
- They help control pests: Many of the more than 1,200 bat species worldwide consume vast amounts of insects, including disease-carrying mosquitoes and damaging agricultural pests. A favorite target of the Mexican free-tail bat is the corn earworm moth, which attacks a host of commercial plants from artichokes to watermelons.
- They are vital pollinators: Bats ensure the production of fruits that support local economies, as well as diverse animal populations. Even bat droppings (called guano) are valuable as a rich natural fertilizer.
- They disperse seeds for countless plants.
In addition to habitat loss, a primary threat to all U.S. bat species is White-nose syndrome — a devastating condition that causes bats to awaken from hibernation early, using up their fat reserves and causing death by freezing or starvation.
The disease has killed more than 1 million bats since it was discovered in New York in 2006, creating what biologists have said is “the most precipitous wildlife decline in the past century in North America.”
Nine bat species in more than 20 states across the eastern U.S. have been affected. And, this relentless disease continues to spread west into new areas.
Scientists are working diligently to research White-nose syndrome in the hopes of finding a way to stop its advance and mitigate its impact.
Our work in New Mexico
The Nature Conservancy recognized decades ago the significance of the Jornada Bat Caves and the site’s importance to the future survival of bats.
The Conservancy has actively worked to find a way to end the biggest threats — unregulated use and guano mining.
Yes, you read that right.
Bat guano was mined from the Jornada Bat Caves in the late 19th century, and guano was still being removed from the site well into the 1980s for use as fertilizer.
Miners blasted holes in the ceiling of the cave to ease the removal of guano, which limited roosting habitat for bats by creating light shafts into the lava tubes.
In the late 1980s, the Conservancy approached Tenneco — a Houston-based industrial corporation that owned the mineral rights in the area — about protection of the site. In 1993, the company donated the mineral rights associated with 5,175 acres including the Jornada Bat Caves to the Conservancy.
Shortly after, Ted Turner acquired the property as part of his purchase of the 358,000-acre Armendaris Ranch. With his help and assistance from the University of New Mexico, the Conservancy got to work restoring the Jornada Caves for the bats.
Setting the stage for a comeback
The caves are actually long lava tubes that intersect one another and run for hundreds of feet. To improve access to guano, miners created “skylights” or shafts to the ground surface.
This practice interfered with the bats’ use of the caves, so the Conservancy worked with the ranch to repair the damage.
We’ve also worked over the years to limit human access so that bats are not exposed to disease or disrupted during critical times of hibernation and birthing.
In fact, we limit Conservancy-sponsored visits to the site to once a year to monitor the status of the caves (from the outside) and witness one of nature’s most incredible sights — a cloud of hungry bats emerging from the cave on their way to a bug buffet.
Danger for dinner
Every night at dusk, during the summer months, waves of bats fly out of the Jornada Bat Caves and head toward the Rio Grande and irrigated farm fields, where swarms of insects gather.
But it’s a treacherous road to dinner. Overhead, a group of raptors, particularly Swainson’s hawks, keep watch. They circle the bats and then dive down, grabbing a bat — and their next meal — if they are lucky.
It’s an extraordinary display of nature in action.
The future of the Jornada Bat Caves looks bright. Ranch staff has taken important steps to limit access and protect the cave site from disturbance, and the Conservancy continues to work with Ted Turner on other efforts to ensure the health of bat populations into the future.
MNN is working with The Nature Conservancy to bring you state-by-state environmental information.