Bats in the Garden

Study finds Fort Worth Botanic Garden hosts greatest variety of bats in Tarrant and Parker Counties

Acoustic surveying by Texas Master Naturalists used sound to identify five species of bats in the Garden.

During the day, the Fort Worth Botanic Garden hums with activity from guests, gardeners, bees, butterflies, and birds. But at night another creature wakes and begins its day. Bats rule the sky of the Garden after dark.

Recent research by Texas Master Naturalists and the North American Bat Monitoring Program shows that the Garden likely hosts five different species of bats. That’s greater diversity than identified at all other local survey locations, including The Nature Center & Wildlife Refuge, Tandy Hills Natural Area and Mineral Wells State Park. Most of these sites identified one or two species.

Why so many? The Garden has everything bats want in a neighborhood: food from insects drawn by the Garden’s native and flowering plants, water from fountains and pools, and a shelter in tall, mature trees.

The tricky task of identifying bats

Bats are difficult to track, because they’re nocturnal and excellent at hiding during the day. But scientists want to know more about the bats of North America, especially the size of bat populations and if those populations are stable or declining.

The multi-agency North American Bat Monitoring Program hopes to remedy the situation. Their most important tool is acoustic monitoring—that is, they identify bats by sound.

As nocturnal creatures, bats rely on sound to navigate in the dark and identify prey. They echolocate by making clicking sounds so high-pitched that humans can’t hear them. Each bat species emits a distinctive pattern of clicks; acoustic equipment records these clicks over a set period. These recordings are then analyzed with software programs that match the clicks to the bat species.

Tracking Texas bats: A job for the Master Naturalists

Volunteers with the Texas Master Naturalists, a program sponsored by the Texas Parks and Wildlife Department and the Texas A&M AgriLife Extension Service, were responsible for monitoring in the Garden and other local sites. Recording equipment—an AudioMoth unit that automatically records wildlife sounds—was mounted in the South Vista law along the tree line of the South Woods in the Garden on May 6-10 and May 20-24 last year.

Later analysis confirmed three bat species in the Garden:

• Mexican free-tailed bat (Tadarida brasiliensis)
• Evening bat (Nycticeius humeralis)
• Tricolored bat (Perimyotis subflavus)

Two additional species were likely heard but could not be confirmed:

• Eastern red bat (Lasiurus borealis)
• Hoary bat (Lasiurus cinereus)

Why protect bats?

Bats play a frequently under-appreciated role in the ecosystem:

• They consume enormous quantities of insects, with surveys estimating they save farmers billions of dollars each year by gobbling up crop pests.
• They serve as pollinators, especially in tropical regions.
• They distribute seeds and nutrients through their guano, helping regenerate forests and crops.

Despite all they do for us, bats are under threat as land use changes eliminate their habitats. At the same time, a fatal fungal disease called white-nose syndrome has devastated bat populations across North America.

For example, populations of the Tricolored bat (Perimyotis subflavus), one of the species identified at the Garden, have been severely impacted by white-nose syndrome. The bat is considered a species of greatest conservation need and has been petitioned for inclusion on the U.S. endangered species list.

Create your own bat-friendly habitat

Area residents can create welcoming spaces for native bats by taking some easy steps:

• Growing bat-friendly native plants, especially night-blooming flowers such as evening primrose (Oenothera biennis), moonflower (Ipomoea alba), and Texas kidneywood (Eysenhardtia texana.)
• Reducing light pollution by turning off outdoor lights at night.
• Eliminating or reducing pesticide use so that bats don’t eat sick insects.
• Protecting natural water sources and/or providing bird baths.
• Installing a bat house. (Learn more at Bat Conservation International.)

Acoustic monitoring is limited in what it can tell conservationists. It can’t be used to estimate the size of bat populations, only their presence in a particular area. But thanks to the bat monitoring program, researchers know more about the distribution of bats in Texas.

And everyone at the Garden is happy that bats have found a safe, welcoming home with us!