Do drones bother birds?

A Biology Letters study on the use of drones to monitor wild bird populations has found that in 80% of tests birds seemed unfazed by drones – even when they were just 4 metres away. The scientists hope to help come up with ethical guidelines on how drones can be used to monitor wild animals.

Drones have huge potential for monitoring sensitive wild animal populations in hard to reach places. The unmanned vehicles can go places humans can’t and report back images and video back to researchers. However, so far there are no clear ethical guidelines on how drones should and shouldn’t be used to spy on wild populations.

A team of researchers set about conducting the first tests on birds to find out how the colour, speed or angle of approach of a drone affected their behaviour. The team tested 3 species of birds: mallards, flamingos and greenshanks.

The researchers used a small quadripcopter drone; currently the most affordable model and one that’s already being used to survey wild bird populations. The drone was equipped with a Hero3 GoPro camera which fed back real-time images to the team.

Flying the drone towards the birds, the team experimented with different speeds and angles to see if the birds showed signs of stress, like moving their heads or tails or getting away from the drone. The results of 204 separate approaches showed that all three bird species were unfazed by the drone’s speed or colour.

Only the angle of approach really bothered the birds. Flamingos didn’t react to any approaches made at 20°, 30° and 60° degrees but were disturbed by 17 out of 18 approaches made from above. The team say these might be more distressing because they’re more like a predator attack.

Overall, in 80% of cases the drone could fly to within 4m of the birds without affecting their behaviours. The team say their study is a first step towards a code of best practice but more testing is needed with different drones and different bird species. In particular, tests with birds of prey should be carried out since online videos show these predators tend to attack drones.

The researchers add that the birds might still be stressed even if their behaviour doesn’t change. Physical tests on the impact of drones of bird heart rates and stress hormone levels need to be carried out as well.