The drone revolution
Conservationists are deploying drones for everything from wildlife surveys to planting forests, weighing whales and catching poachers.
WILDLIFE SURVEYS
Drones have proved ideal for monitoring inaccessible seabird and sealion colonies, and for locating herds of herbivores in remote wilderness areas (oryx antelopes in Namibia, for example). In a Welsh conifer plantation, thermal-imaging drones were used to detect nesting nightjars, picking out their 40°C bodies against the colder ground – these birds are nocturnal, well camouflaged and easily disturbed, so notoriously tricky to study by traditional methods. In Sumatra and Borneo, thermal-equipped drones have counted orangutans and proboscis monkeys scattered through the forest canopy.
RESEEDING HABITATS
An Oxford start-up has used drones to sow grasses and trees over old Australian coal mines, and replace mangroves in Myanmar. After aerial surveys to locate suitable sites, biodegradable seed bombs were fired from mid-air. Theoretically, a team of two operators can carpet-bomb thousands of seedlings a day, but critics say the emotional connection involved in traditional tree planting is lost.
SCALES IN THE SKY
Not only can drones map and count trees in a forest, they’re also able to estimate the height and girth of individual trees, by means of laser pulses, enabling the forest’s overall health to be assessed. Off the coast of Argentina, marine biologists have employed drones to ‘weigh’ southern right whales, by taking aerial images from which the cetaceans’ volume and mass were calculated. If the same whales are rephotographed in future, it should be possible to track their growth over time, and thus their fitness and energy requirements.