Team Flies Drone Camera to Detect Bird Eggs in ROW
In July, CTR’s Mike Murphy pulled together diverse staff resources to solve a problem for TxDOT. The Austin District of TxDOT needed to remove some trees in the right-of-way along FM 969 (Martin Luther King Blvd) near Bantom Woods Drive to allow for installation of a utility line. However, they cannot cut down trees that have bird eggs or fledglings in them. The trees clearly had nests in them—the question was whether the nests had any current occupants. Jon Geiselbrecht, an Environmental Specialist with the Austin District’s Environmental Section, needed photos showing the inside of these nests to determine if the trees could be removed. Usually TxDOT would use a bucket truck to lift a person to the height of the nests, but the presence of electrical lines on both sides of the trees prevented such access. The utility contractor was on hold until the photos could be obtained.
Jon reached out to the Austin District’s Director of Maintenance, who in turn reached out to Mike Murphy, who administers the CTR interagency contract with the Austin District (an arrangement allowing the Austin District to access CTR’s various research and implementation resources to solve problems and enhance TxDOT services). After personally investigating the site and taking some initial photos, Mike put together a sort of task-specific A Team:
- senior staff researcher Manuel Trevino brought years of field photography experience,
- newly hired researcher Juan Porras-Alvarado was on hand to assist with operating the drone,
- contracts specialist Ashley Williams contributed her extensive birdwatching expertise,
- student researcher Yifan Lyu loaned his drone video camera and provided some initial training on its use, and
- faculty researcher Christian Claudel drew on knowledge of his field to make recommendations for the imminent purchase of our own drone camera.
Manuel and Juan took video and ground photos. Juan flew the drone and photographed what appeared to be a nest in Tree 1; it turned out to be an abandoned squirrel’s nest, thus allowing the utility contractor to remove that tree. Manuel flew the drone and photographed Tree 2, discovering a western kingbird nest with four eggs. Flying the drone and obtaining the photos proved quite challenging due to wind, the tree branches surrounding and obscuring the nests, and the electrical lines on both sides of the trees.
Ashley established that two types of birds were nesting in the area: a western kingbird and a finch. She provided some critical information about the western kingbird and its nesting habits, helping the team prepare for the drone flights. For example, she pointed out that we could not use a long pruning hook to trim small limbs around the nest to gain a better view, since these limbs were part of the support structure for the nest. Once Manuel had photos from the nest in Tree 2, Ashley was able to confirm the species. She also identified the nest in Tree 1 as most likely a squirrel’s nest due to the type of construction.
Chris provided expert advice about the need for a more sophisticated drone to provide additional flexibility for this type of work. His recommendations included purchasing a drone with a camera that can take both still photographs and video imagery, coupled with zoom capability. This setup would allow taking photos a safer distance from the tree and other obstacles. In addition, a drone that can make longer flights before recharging would be useful for situations where multiple nests might require investigation—obtaining successful photos/video at even one nest location can be time-consuming when multiple obstacles are present.
Chris’s advice will guide our planned purchase of three professional-grade tethered drones. Tethered drones are connected by a power cable to a base station and therefore can hover at heights up to 800 feet indefinitely. (A battery-powered drone, by comparison, has a flight duration of around 30 minutes to 45 minutes.) Prior to this outing, we’d already determined that a new task for the interagency contract will be using drone cameras to monitor traffic incidents on IH 35. Both Juan and Manuel received drone flight training from a local drone service (DroneTex), which will useful in this task.
Following the success of this outing, Jon noted that he may call on CTR again soon to conduct additional drone photography flights to help determine the presence of nesting birds. This is a new service CTR can provide to the Austin District.