The limits to applying drone technology to nature conservation are literally defined by your imagination, says Ezemvelo KZN Wildlife ecologist Dr Debbie Jewitt.
She was speaking at DroneCon 2018 to explain just how the conservationists in KwaZulu Natal have been using drones in their daily work; from game counting to monitoring endangered species and even anti-erosion treatments on large areas of nature reserves – none of which would have been as efficient or even as practical before the advent of the technology.
She showed a satellite image of Weenen Game Reserve, a big tract of land expropriated by the state in 1948 because it had been desperately overgrazed. It was eventually given to the then Natal Parks Board in the early 1970s and proclaimed in 1974 as a reserve to be restored to its former glory. The biggest problem though has been erosion.
The scale is so great that it is both time consuming and difficult to monitor. Freely available satellite imagery was no help either because it did not have the resolution or the depth of detail. The drone camera did, she says, and put up a picture on the projector to show the difference.
The satellite image is grainy and blurred. The drone image of the same area is crisp. Then she zooms in, literally to the granular detail showing the bricks on a little wall that has been built. Ezemvelo has also been using drones to monitor the efficacy of herbicides in killing off invasive species in Weenen. Thermal imaging from drone flights show which plants and trees are photosynthesising and which are not, with those not, effectively killed by the herbicide.
Another problem, that Ezemvelo had to monitor, was the killing of vultures on powerlines. Traditionally this would involve walking the length and breadth of the pylons. The drones solved this. The only problem was that there were no carcasses, thankfully, to test the drone on, so they improvised, using Jewitt’s Ezemvelo issue jersey to create the “green-backed jersey vulture”, which was easily spotted from the drone at height with enough resolution to zoom in and monitor its skeleton structure, down to the broom stick for its wing span.
Drones are now being developed to help install bird flappers on power lines, artificial bird flight diverters. Normally this is a time consuming, expensive and potentially dangerous task involving lots of people, disruption of power supply and the use of specialised equipment such as cherry pickers to access the line. Drones however could attach these at a fraction of the cost and zero disruption.
Drones have also yielded incredible results in the recording of endangered species such as vultures in Oribi Gorge.
“The traditional observation method was to stand at the foot of the gorge with binoculars or spotting scopes, but the vultures conceal themselves very well,” she quipped.
Flying a drone past changed all of that – dramatically. Between 2001 and 2017, conservationists had recorded 58 nests. Last year, using a drone, they detected 94 nests.
“It wasn’t that the birds had suddenly increased, just that our detection methods had improved.”
There are many other uses for drones, such as game counts, especially in the Drakensberg.
“We want to use the drones to count crocodiles, because nesting crocodiles are very territorial and will attack the rangers when we go into count, so we can never get close enough.”
There are inherent challenges with using drones.
“We need more work on AI and software,” said Jewitt, “the processing work on the drone data is problematic, it is immensely time consuming. AI will be able, using algorithms, to age elephants using their size. We need to find ways to be able to sex herds of buck and distinguish between the different species – especially from the air.
“Nasa has created an algorithm called fluid lensing to see through water. Now we can see parrot fish, sea cucumbers, sharks and other marine life from the air, from the drones.”
There’s also the ethical issue of interacting with wildlife using technology, protocols need to be drafted around safe operating distances.
“We need to be cognisant of the effects on species. We had an instance where a giraffe mother with her calf got skittish at a distance of 85m, while the rhinos were chilled up to about 60m.”
There’s also the issue of drones being attacked by animals, especially birds of prey. Recently a fish eagle in Zululand took out a drone, while birds of prey are being trained in Europe by their rich owners to take out drones being flown by paparazzi over their properties.
There are practical challenges too: like getting drones out of trees, insufficient battery life, flight times and wind, especially in the Drakensberg.
The pros though, outweigh the cons, with huge opportunities in terms of law enforcement, anti-poaching initiatives and search rescue, especially when it comes to places that would be difficult and sometimes impossible to reach or work in.