Drone technology supports bat conservation efforts in hard to reach places.
By Paul Hormick
Bat Conservation International researchers and technicians often have arduous journeys. Colonies of bats can be miles from roadways and established trails and in rough terrain. To reach these destinations BCI crews need to know the lay of the land as best they can.
This is where Bianca Signorini comes in. The GIS analyst is also an Unmanned Aircraft Systems pilot, which means she flies drones. “I provide geospatial support for our field crews,” she says. “I make maps for them to navigate to abandoned mine features, review their survey results, and then use GIS to help them with the reporting process after the field surveys.”
As part of its Habitat Protection & Restoration Program, which protects bat colonies, restores their habitats, and mitigates threats to their roosting sites, Signorini currently supports BCI’s abandoned mines initiative, which seeks to close the abandoned hard-rock mines in the American West and Southwest. In the Southwest alone the Bureau of Land Management has inventoried 57,586 mines, 80 percent of which need some form of investigation or remediation.
“A large part of our role in this is to make mine closure recommendations using results from subterranean bat habitat surveys,” says Signorini. The Medford, Oregon native adds that closing the mines is important for public safety, rehabilitating landscapes, and keeping certain wildlife habitats intact. The Bureau of Land Management, Department of Energy, and the Forest Service funds BCI’s work in this area.
A recent project had Signorini flying her drone over a steep sided canyon, part of a Wild and Scenic river corridor in a remote location in Oregon. Her mapping of the area is aiding in the investigation of tunnels that were excavated in the canyon and later abandoned in the 1930s. The site is largely inaccessible to the public, with no established trails. “So our job here was to survey and find out if bats were indeed using these tunnels, which they are,” she says.
Flying her drone for about an hour and a half, Signorini collected 3,000 images of the river corridor and canyon. She then used a process called photogrammetry to “stitch” the images together—a process that may take a computer 10 to 15 hours to complete—to create a 3-D model.
Besides aiding BCI field crews, imaging from the drones works in a larger context. “It was beneficial to create a 3-D model so they can have a deeper understanding of the site to make closure recommendations that are appropriate for a regulated area,” Signorini says. Despite being so inaccessible, some rambunctious hikers have nonetheless discovered the tunnels, possibly disturbing the bats. With Signorini’s work BCI can determine if they should install bat gates, shields in tunnels or mine shafts that allow bats to pass through but keep humans out.
For a single project Signorini may typically map an area of over 1,000 acres. She flies her drone low enough to take very high resolution images yet high enough to avoid tall trees and power lines, usually between 200 feet and the FAA drone height limit, which is 400 feet. The flight heights can be affected by other factors, such as being close to an airport.
The flight time for such a project may take only an hour or two, but the running time may range from a half day to a full week, depending on the complexity of the terrain and the type of drone being used. Signorini can find herself spending even more time in the office getting the proper authorizations and performing data processing.
In a little over a year’s time since joining BCI, the outdoor enthusiast and backpacker has flown drones in Texas, New Mexico, and Arizona. Last week, she was in her home state of Oregon test flying a new fixed-wing drone called a WingtraOne, which she plans to use to create two dimensional and three dimensional landscape models.
The new drone can also collect multispectral imagery, which gathers information within specific bands of the rainbow and even into the infrared. This type of imagery can give a good indication of vegetation health and can indicate if plants are lacking nutrients, such as nitrogen. This information helps BCI with landscape and stream restoration, as well as monitoring the flora of restored sites.
Several developments are on the horizon for BCI’s drones. “What we’re going to start using drones for—this is still a young initiative—is scouting out mines that haven’t been documented,” Signorini says. She is also eager to map BCI’s Bracken Cave Preserve in Texas. The project will encompass high-resolution mapping of the preserve’s 1,500 acres. The drone technology can also look for karst features that could indicate cave systems that serve as additional bat habitat in the area. Drones can also identify areas that may be sensitive to groundwater contamination.
“When I was in school I knew I wanted to do land management stuff,” Signorini says. Describing herself as “kind of a gear geek,” working with drones seemed like a good fit for her. “Drones, by nature, are insidious. Their origins and uses are for surveillance and a lot of darker purposes. Being able to take this technology and turn it around and use it for good. That’s enormous for me.”
GIS Analyst & UAS Pilot Lead
Bianca joined BCI in a part-time capacity in November 2022 and became a full-time staff member in July 2023. Her expanding role includes providing geospatial support to habitat protection and restoration field crews and creating a variety of geospatial products internally and externally to BCI.
She is also an FAA Part 107 certified UAS pilot and manages BCI’s new drone fleet, which is put to work creating highly detailed maps, locating abandoned mine sites or cave entrances to be evaluated for sensitive bat habitat, and continued monitoring of habitat restoration sites. As BCI’s geospatial and UAS capacity grows, her expertise with these tools opens up collaboration opportunities internally and externally to further the organization’s mission to end bat extinctions.
Bianca is located in beautiful southern Oregon. When she isn’t making maps and flying drones, she can be found hiking, reading, or practicing barebow archery.