Intelligent Scarecrows: Pattern Recognition Methods for Reduction of Human-Wildlife Conflicts

Scarecrows

that speak bird

Researchers from Aarhus University are behind the development of an intelligent scarecrow which can prevent large flocks of birds from landing on fields and eating the crops. This solves a very large economic problem in the agricultural sector.

Researchers from Aarhus University are behind the development of an intelligent scarecrow which can prevent large flocks of birds from landing on fields and eating the crops. This solves a very large economic problem in the agricultural sector (Photo Aarhus Universitet)

Every year giant flocks of birds land on the fields all over Denmark and devour large parts of the yield or destroy grazing areas. This leads to considerable financial losses for the farmers who cannot do very much to prevent it from happening.

But now it looks as if researchers have discovered an effective, intelligent system to scare the birds away. With the help of speech recognition technology, the system senses the presence of the birds based on their sounds and can then emit an alarm.

In particular flocks of geese, seagulls and rooks have created problems for farmers and in the case of geese, the population has grown markedly in recent years. They often arrive in flocks of several thousand birds that can eat a great deal very quickly.

Computer speaks and understands bird language
Today farmers use gas cannons and other systems, using different acoustic and visual stimuli to scare the birds. None of these methods are effective, however, because the birds quickly become accustomed to the systems and ignore them.

What is unique about the researchers’ new version of an intelligent scarecrow is that it can measure its own effectiveness in scaring the birds away. By registering sound, it can identify whether the birds are landing, whether they have settled on the field or whether they are fleeing. In other words, the system is adaptive. It measures whether its stimuli have the desired effect and reacts to this information.

"The system emits the first alarm to scare off the birds as they are on the way to settle on the field. If this does not work and the flock still lands, it emits a new alarm to scare the birds away," says Kim Arild Steen, PhD student at Aarhus University.

The researchers have mapped the connection between the behaviour of the birds and their sounds based on many hours of video and audio recordings of geese. The method is based on signal processing, pattern recognition and image analysis, which, when combined, makes it possible to translate the birds’ own language.

Ready for the market
At present, the intelligent scarecrows have been erected in Denmark and also in a single case in Germany. So far they have been very effective at scaring away barnacle geese, greylag geese and rooks.

The scarecrow has been christened AniMan and the three researchers behind the invention have formed the company Wildlife Communication Technologies ApS.

The AniMan scarecrow

A small flock of rooks is airborne to scout for food for the hundreds of other rooks at home in the breeding colony. They spot a field of strawberries and get ready to land as rooks love strawberries. In fact, the large black birds are amongst the strawberry grower’s worst enemies.?

But just as the flock gets ready to land and taste the delicious food, a well-known sound echoes through the air and causes the rook patrol to panic and flee. The well-known sound is actually the sound of rooks as they panic and flee.

That the sound does not come from the flock itself but from a speaker connected to a computer in the field below is something they do not notice.

Even if the rooks decide to land anyway – and maybe to even ignore the scarecrows’ warning in their own language to leave the area again, the computer still has an "arsenal" of other sounds that will surely frighten off the unwelcome guests. This includes sounds such as dogs barking, gunshots, birds of prey shrieking etc., and the clever thing is that the computer itself decides when it is time to change its bird scaring tactics. It does this by constantly listening to whether the birds react as intended to its stimuli.