The Bird Control Group based in The Netherlands has developed a new type of scarecrow called the Agrilaser which uses laser beams to spook birds. It is intended for use in agriculture to protect young seedlings and prevent contact between wild birds and farmed poultry. It can also be used to protect items from fouling by bird droppings.

The whole thing sounds a bit crazy, almost science fiction but they are serious. The manufacturer explained the principle of the system:
"The Agrilaser Autonomic is a fully automatic bird repelling system that deters birds permanently, once configured. This idea of deterring birds with a laser beam was inspired by nature. Birds perceive the approaching laser beam as a physical hazard. This triggers a survival instinct and causes the birds to fly away. The constant presence of the moving laser beam keeps areas free of birds 24 hours a day, 7 days a week. "

The website in German makes it clear that they see a large market for their product in the east of the Netherlands. Technically the system uses a (green) class 3B laser (500 mW power max) mounted on motorized gimbals so that the beam can be directed as required. This generates a powerful spot of light which has a range up to 2.5 km and can be steered over the ground or other surfaces. One version of the system is powered by solar cells with rechargeable batteries so it is able to operate in the field without a connection to the mains.

If you are a dog or cat owner you know already how they are fascinated by the moving spot of light from a laser pointer (cats especially). They see the light spot as something small and harmless to chase, but birds react differently; they see the approaching spot as a threat which triggers their escape reflex and makes them fly away from the fields and rooftops.
Bird scaring demo. Source: Bird Control Group

So far, so technical. However, the German Nature And Biodiversity Conservation Union (NABU) has criticized the use of agrilasers, saying that unscrupulous landowners could use them to deter protected birds from nesting so that land can be developed, undisturbed by nature conservation orders. Another aspect is safety; the laser used in the equipment is 1000 times more powerful than a standard laser pointer. Any malfunction of the system, which is mounted outdoors, could end up causing serious damage to the retina of a human or animal. Freestanding laser systems could also attract pranksters and that will always end in a bad outcome. Weighing up the benefits and risks may not be quite so simple.