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Recorded distress calls scares away others of same bird species

Scarecrows replaced by digital devices

Tags: Excerpts from the Windmill

ROSMALEN, the Netherlands – Scarecrows are going digital, creating efficiency in a haphazard struggle in fields between winged and legged harvesters, between birds and growers. It was never particularly effective, the use of straw men as scarecrows. Neither were booming air cannons which proved to be very problem-some for the neighbourhood. Birds soon figured out that nothing much happened beyond the initial scare, leaving growers with double pain, loss of crop and unhappy neighbours. Innovators think they offer the right solution: AlcetSound’s digital bio-acoustic bird repellers, basically bird distress recordings.

The search for peace with neighbours while warring with birds over crops such as cherries, berries, apples and pears had become urgent when the noisy air cannons turned into a source of constant irritation without having an impact on the ways of the birds. With housing developments often closing in on crop farms, the cannons undermined the goodwill growers needed in the community.

The alternative, less-bothersome digital distress calls that are being heard in an increasing number of Dutch fields, are actually recorded in Spain by fowlers catching birds. The resulting distress calls of different species were recorded and copied for use in digital systems for growers and other farming operations. Fighting fire with fire as it were, the distress calls of starlings are recognized by starlings everywhere, the crow’s distress sounds will send the crow species packing, seagulls hearing the warnings of its kind flee and even the distresses of songbirds scare away their kind from certain crops.


The distress calls from their own kind cause the birds to retreat amazingly quickly. Although birds easily ‘grow’ accustomed to such calls, vendors of the devices suggest various routines to keep winged intruders on edge. The device also attracted the attention from Faunafonds, the semi-government agency that settles damage claims from farmers, hired a researcher to study its effect in five orchards where crows caused a lot of damage by picking on choice fruit. In four orchards the damage caused by crows dropped substantially. In the fifth orchard, the crows grew accustomed to the distress calls because the devices were too long stationed in one place. The researcher recommended in such instances a blend of devices, including the air cannon.

While some neighbours still find reasons to complain about noise, other entrepreneurs are flocking to the concept. One of these, a dairy farmer, wanted to free his barns of thousands of starlings where they housed in the rafters. The birds were contaminating the feed with bird droppings, a potential for disease. The dairyman considered various things but each option was even less attractive than the other. A search on the Internet introduced him to AlcetSound. A walk through the barns with the hand-held device screeching the distress calls quickly sends the birds packing. To keep them out, he walks through the barns with the device at irregular intervals and has not noticed any reaction from other animals.


AlcetSound also can be used at seeding time. One crop farmer had to reseed his corn maze field when the birds had picked away about thirty percent of the seed. With device in operation, the intruders kept a safe distance. Other farmers have started to use AlcetSound with success to scare away migrating geese and starlings from sensitive area. Flocks of geese easily ruin grass mats and colonies of starlings can cover an area with layers of their droppings, often difficult to clean. The same problem occurs on bridges where rows of birds can be sighted resting. Only insiders know of the damage droppings cause to resting places on the steel structures. Pre-programmed devices installed on bridge structures can make a significant difference in cleaning and repainting costs, innovators say. The units also are used on ferries, at yacht clubs and on ships that ply coastal waters where seagulls leave their marks. Even garbage dump operators find it useful to keep these messy birds on a distance with the digital distress calls. Nowhere in the Netherlands is the use of the bird repellers more compelling then around runways on airports. Already a densely populated country, the Netherlands still goes out its way to create more nature parks and bird sanctuaries. At the same time, the Dutch accommodate a number of busy airports. Especially at the take-off time of planes, straying geese could easily down such a ‘bird’ and cause hundreds of casualties. To operate safely, airports such as Schiphol and Rotterdam employ bird watchers who operate vehicles outfitted with AlcetSound’s bird repellers and so keep the possibility of collisions to a minimum.