Bird scaring is the dispersal of birds using stimuli that make them feel uncomfortable. The majority of systems are based on sights or sounds connected with bird predators. Scaring is often thought by the uninitiated to be a panacea – a cheap, simple, and totally effective solution to all bird problems. However, this is not at all the case. Birds are intelligent creatures that can rapidly become habituated to initially frightening sights or sounds once they realize that they pose no real threat. Often the most effective scaring techniques are those involving a combination of systems, both visual and audible, that are actively managed on an ongoing basis.

Bio-acoustics is the use of digital technology to record, analyse and broadcast the natural distress calls of birds or the sounds of predatory species. Broadcasting distress calls elicits different reactions in different species. Social and aggressive birds that communicate verbally within colonies, such as gulls, would usually fly towards the source initially to see if they could mob the ‘predator’ and help their kind. When the call ceases and they do not find a ‘predator’ they are then unnerved or ‘scared’ by the possible danger and disperse. Birds that do not communicate much verbally, or do not have bills or claws to threaten predators, such as feral pigeons or starlings, will tend to stop and assess the situation, then disperse directly. The calls of predatory species can be used as part of an overall control strategy but their impact generally relies upon the additional scaring measures that are used in conjunction with these calls.

Equipment comes in a number of programmable forms including vehicle mounted, such as those used on airfields and in the landfill industry, hand held loud hailer units and building mounted systems. Played back at a natural sound level, bird distress calls are not intrusive to people and generally remain unnoticed in places where the public is present. It is always best to use bio-acoustic systems as an element of an integrated approach rather than as a stand along system in controlling pest species.