Why drones are flying high in conservation efforts

Unmanned aerial vehicles (UAVs), commonly known as drones, have many different field applications for conservation. Experts that use drones on Nature Conservancy of Canada (NCC) properties tell us how they work, and how these UAVs are no ordinary drones. 

Rhonda Millikin: Sage and Sparrow Conservation Area, British Columbia

Rhonda Millikin (left) and her former field assistant Ruth Joy (right)

Rhonda Millikin (left) and her former field assistant Ruth Joy (right)

Dr Rhonda Millikin is the head of the habitat assessment and data management unit at the Canadian Wildlife Service, Environment and Climate Change Canada. Since she began working in the shrub-steppe ecosystem of British Columbia in the mid-‘90s, when measuring tape and topographic maps were all you had to mark your study area, technology has evolved significantly and now provides researchers with remote sensing devices like hand-held GPS and drones.

For Millikin — and other scientists — drones offer new observations of species and their habitats. While most wildlife react to humans who are nearby, duringtrials with waterbirds at coastal estuaries in British Columbia[1] Canadian Wildlife Service researchers found that drones can record undisturbed wildlife behaviour. Walking into undisturbed habitats can also inadvertently introduce invasive species, which can be avoided by using drones. Mapping and monitoring habitats is easier with drones as well. “We can resample areas over a larger landscape and compare parcels with different land uses, to determine if a habitat change is happening because of climate or development, for example” says Millikin.  

At the NCC Sage and Sparrow Conservation Area near Osoyoos, British Columbia, Millikin recently used drones to study sage thrasher habitat.

For Millikin and her team, the question was whether drones could be a more efficient and effective way to identify nest bushes of the size required by endangered sage thrashers. “To find rare birds like the sage thrasher, people tend to go back to the same place where they know the birds will be. But with the change in climate, ideal habitats for the sage thrasher may shift further north. Drones help us get ahead of the curve and find these places.

Beyond helping Millikin and her team find new habitat areas, they will test the potential for drones to assess whether habitat management and restoration measures are working in protected areas.

Millikin explains that to support the sage thrasher, a minimum of 10 per cent of a habitat area must have elliptical-shaped  sage greater than 84 centimetres high and 71 centimetres wide “If we reach that number, we can say we have ideal habitat. If it is less than that, we may want to adjust the way we are managing the land.”

Based on combined data from the past 100 years and field observations of sage thrashers, Millikin and her team created a grid for the drones to fly within. “We knew there would be nest bushes in critical habitat areas. We weren’t sure how high the drone should fly above the ground, or how to detect the nest bushes in the landscape. Todd Manning[2] used remote sensing to develop a 3D model of the vegetation. He found a height that worked well for detection of ideal nesting shrubs.” Millikin’s team confirmed the validity of the approach by “training” the remote sensing software on the drone on an actual nesting site in the field so it could better recognize other nesting shrubs in the areas.

Drone flyover during winter survey

Drone flyover during winter survey

The height in which drones fly is also important to ensure that the birds remain undisturbed. To determine the ideal altitude from which to detect sage thrasher nests and not disturb nesting birds, Millikin and her team looked at ways to minimize the number of times the drone passed over an area and experimented with different altitudes. Ultimately, they found 30 metres to be the ideal drone cruising altitude to capture the information they needed without disturbing the birds below.

[1] Drever, Mark, Dominique Chabot, Patrick D. O’Hara, Jeffrey D. Thomas, André Breault, and Rhonda L. Millikin 2016. Evaluation of an unmanned rotorcraft to monitor wintering waterbirds and coastal habitats in British Columbia, Canada. Journal of Unmanned Vehicle Systems.

[2] SRS Avimetrics,  Victoria, B.C. V9C 4H5, Canada

Rotary or fixed-wing drones? Just ask waterbirds

Simply stated, a rotary drone resembles a helicopter, while a fixed-wing drone has wings like an airplane.

To humans the difference may appear strictly technical, but for the study of sage thrashers using fixed wing versus rotary drones could be a perceived as a life-and-death question. Why? In the eyes of birds hunted by hawks, fixed-wing drones can look like predators. While a fixed-wing drone’s “predator-like” appearance upset waterbirds in the wetland habitat that Canadian Wildlife Service researchers tested, a rotary drone made observations nearly without incident.

Drones offer unbiased data, but can’t replace human observers

The unbiased and impartial nature of the data that drones gather is one of the most important features of drones to scientists, according to Millikin. “When you use drones, you will measure and get data that isn’t biased by human preference or condition. When you are dealing with legally protected species and making recommendations to landowners, you want to be confident in your data.”

In addition, there are some areas that are very sensitive to invasive species, ground compaction and other impacts of human access. “Drones let us sample these areas remotely rather than on foot. Birds move over vast landscapes, and it can be hard to cover large areas when you are walking. Back in the day we used compasses, flagging tape and so on — it was much more difficult and time-consuming than getting data from the drones.”

Millikin emphasizes that for all their technical capabilities and lack of bias, drones cannot replace flesh and blood scientists. “We are augmenting, and not replacing, the human observer. We need to have a field biologist ask the right questions and validate the information that we are getting out of the drone photography.”

Dave Halstead: Old Man on His Back, Saskatchewan

Section of Old Man on His Back project area (approx. 39.5217 ha) taken by eBee Sensefly with a Sony WX220 RGB camera and processed using Pix4D and ArcGIS. Courtesy of the Natural Resources Technology Applied Research Group at Saskatchewan Polytechnic.

Section of Old Man on His Back project area (approx. 39.5217 ha) taken by eBee Sensefly with a Sony WX220 RGB camera and processed using Pix4D and ArcGIS. Courtesy of the Natural Resources Technology Applied Research Group at Saskatchewan Polytechnic.

Dave Halstead is a senior research associate with Saskatchewan Polytechnic’s Natural Resource Technology department and another old hand at UAVs. He eschews the term “drone” since it’s not commonly used in professional circles.

Halstead was called in as the UAV expert to assist with vegetation analysis at NCC’s Old Man on His Back Prairie and Conservation Area (OMB) in Saskatchewan in support of his colleague Joanne Marchand’s work in this area. The Saskatchewan Polytechnic Project is a Sustainability Initiative Fund Project funded internally and in collaboration with NCC. The study is entitled: “Comparative Range Management Strategies on the Southern Mixed Grass Prairies; A Collaborative Research Project of Saskatchewan Polytechnic, The University of Saskatchewan, and the Nature Conservancy of Canada.”

Halstead’s team was asked to participate because they have the technical expertise, equipment and required certification for doing this kind of work. To get a comprehensive picture of the Ranch, Halstead and research technologist Leila Benmerrouche flew the UAV over the six large pastures that NCC staff had identified, at about 35 hectares at a time. NCC will use the data that Halstead and Benmerrouche have gathered from the UAVs to examine grazing patterns — which vegetation is being selected by plains bison and cattle — as well as the types and the condition of vegetation on OMB. Along with OMB’s work with animals outfitted with GPS collars[1] , this will give NCC staff an accurate picture of what grazers are eating, and where they are eating it — valuable information not just for the conservation of the property, but for ranchers.

The UAV used was a Sensefly eBee. It can be outfitted with an RGB camera for visuals, a near-infrared camera to show vegetation health, or a multi-spectral camera that covers visual and infrared bands at the same time. Because the drone is fixed-wing style, it can cover a lot of ground. According to Halstead, “a rotary UAV would be hard-pressed to cover that much ground without switching batteries multiple times.”

In the three days that Halstead and Benmerrouche were at Old Man on His Back, they flew 12 missions with the eBee and seven with a DJI Phantom UAV. Since Halstead knew his colleague Marchand couldn’t be there, he used the 4K video camera on the DJI Phantom to capture overhead and closeup views of the vegetation so she could review it for her study. The result was a stunning 4K video, which can be viewed below, with beautiful, big vistas of open country.

Halstead says that the power of the drone isn’t in the tech, but in the sensors and knowing what to do with the imagery and data that the drone collects. “Everybody is interested in the drone until they fly one for a period of time, and then they ask where the thrill is after that. The power is in the sensors, knowing what to do with the data, and bringing out the detail in the data. The drone itself is quite secondary to all of that.”

Saskatchewan Polytechnic features high-end Geographical Information Services (GIS) facility

If you want to learn how to film and analyze UAV data, Saskatchewan Polytechnic is the place. The 3D model shown above was rendered using multiple photos captured at Old Man on His Back using photogrammetric mapping software available at the Saskatchewan Polytechnic GIS lab. “We teach a full-year certificate course for people who have completed a previous diploma or degree, and it’s a nice add-on for resource management. The lab has 20 high-end computers. We purchased a server specifically for all of our UAV work because of data storage requirements. We have a LIDAR sensor, which is like sonar only using light instead of sound. “It sends out 300,000 pulses of light per second and can survey the terrain by precisely mappingthe source location of the reflected light. Tens of gigabytes of data can be obtained in a 10-minute flight.” 

Like Millikin, Halstead believes drones can’t replace humans, and that the work of flying them should be done by professionals. “There are many hazards and regulatory components associated with flying UAVs, and when you’re an operator, you’re essentially a pilot. You take ground school and flight school in order to fly these craft, as well as apply to Transport Canada for your flight operator’s certificate.” So while it is serious business to fly a drone, they yield staggering results that may make the learning curve — and necessary licenses — worth it.

Taking flight with J Lo

Megan Lafferty, a conservation biologist for NCC in Newfoundland and Labrador, is excited about an incoming celebrity in the form of a new drone named J Lo. Recently, a donor came forward who wanted to invest in technology that would advance the program in the Atlantic Region. There are properties, such as Lloyds River, which are difficult to observe with their rugged terrain. “Aerial imagery is good for spatial analysis and landscape planning. The province does flyovers every few years, but our drone will be closer to the ground and we won’t have to wait to get up-to-date data.  This will also let us take some aerial shots of a more artistic nature.”

The drone will be purchased by the end of the year, and Lafferty says “We’re getting our ducks in a row to run the program properly. We’re getting training on how to fly the drone, flight operation certificates, and everything else we have to do to get ready to fly for the 2018 field season, which is usually from May to September.” The name J Lo was inspired by John Lounds, president and CEO of the Nature Conservancy of Canada.

UAVs are much more than exciting gadgets. They offer an efficient way to collect a treasure trove of data that can be used for conservation. They will help NCC to do a better job of managing our properties and the species and habitats we are working to protect.