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Tips for bird dispersal with lasers



There are at least two potential consumer uses for lasers outdoors, pointing out stars in the sky and dispersing birds. This page discusses tips for deterring and dispersing birds.


Summary


LaserPointerSafety.com does not recommend that ordinary consumers use lasers to scare away unwanted birds. The right type of laser with a wide, low-powered beam is not readily available so there are too many potential safety problems for the birds, for the laser user, and for bystanders.

Also, there is a chance of accidentally having the beam be on or near an aircraft; this is illegal in many countries and jurisdictions. Finally, some species of birds may be only temporarily repelled by lasers; after a few minutes or within a day, studies indicate they will return.


Bird deterrence and dispersal


Some consumers have asked about using lasers for bird dispersal.

A September 2003 U.S. Department of Agriculture publication, “Use of Lasers in Avian Dispersal” says that lasers are “safe and effective species-specific alternatives to pyrotechnics, shotguns, and other traditional avian dispersal tools.” A key phrase is “species-specific”. For example, a 2002 USDA study of crows (listed below) concluded that lasers do not work for more than a few minutes of dispersal, and are therefore not recommended for crows.

LaserPointerSafety.com believes there is a difference between serious, professional use, and consumers ordering possibly over-powered lasers off the Internet and simply waving them into trees and the sky. This is especially true in today’s environment where authorities are very sensitive to lasers being aimed into the air by ordinary citizens.

Our recommendation is that consumers should not use lasers against birds, especially Class 3B and Class 4 lasers (output power of 5 milliwatts or above). If a person feels they must try this, it should be done very carefully, with continuous monitoring of the sky so that aircraft are not accidentally targeted.

Discussion of a commercial bird dispersal laser


The following is based on information from the TOM500 Bird Deterrent Laser System developed by LORD Ingenierie of France.


Pic 2012-02-22 at 10.35.04 AM
The TOM500 laser is much more than a pointer. For one thing, the system weighs almost 1000 lbs.


The TOM500 uses a green laser wide beam roughly 6 inches in diameter, which constantly sweeps a few inches or feet above airport runways. The beam enlargement does two things:

  • The beam looks like a stick to the birds, according to LORD. They see this “stick” and disperse.
  • Enlarging the beam helps make the beam bright but safe. The laser is rated at Class 2M. Class 2 means the direct beam is eye-safe for a short (1/4 second) unintentional exposure due to humans’ natural aversion to bright light. (The “M” part means that optical aids such as binoculars or telescopes should not be used to view the light, since it could be concentrated to a potentially hazardous level.) The TOM500’s power is 0.7 milliwatts into a 10 mm diameter aperture. The human eye’s night-adapted pupil is about 7 mm, so even less light would enter the eye.

However, such large-beam, low-powered lasers are not readily available to ordinary consumers. Tight-beam, high-powered lasers are much more common. Using such a laser with birds may be a hazard to the animals. Certainly, any Class 3B or 4 handheld consumer laser (for visible lasers, above 5 mW) is an eye hazard to humans. You would not aim these at persons, so it stands to reason that birds’ eyes could possibly be harmed depending on the laser power.

Survey of lasers


A 2003 review of methods of bird scaring techniques and potential alternatives by the U.K. Department for Environment, Food and Rural Affairs (DEFRA) listed many ways of dispersing birds. If you are simply interested in getting rid of annoying birds, this document may be useful.

The laser section of the document said the following:

As the demand for non-lethal, environmentally safe methods of bird scaring has increased, interest has grown in the use of lasers, particularly low-power lasers that work under low light conditions. The low power levels, accuracy over distance, silence and the ability to direct them on specific problem birds, makes laser devices an attractive alternative to other avian scaring devices. Birds are startled by the strong contrast between the ambient light and the laser beam. During low light conditions this technique is very selective, but at night the light beam is visible over a large distance and hence can cause non-selective disturbance. Unpublished data from trials on French airfields indicate that these devices are ineffective in bright daylight conditions, and the device worked best when shone in birds’ eyes. Results of pilot trials undertaken on UK cormorants and goosanders support this effect (McKay et al. 1999).

Lasers have been tested in a number of countries. In France, a laser gun was used to disturb cormorants from a night roost (Troilliet pers. comm., cited in Boudewijn and Dirksen 1996). During cloudy weather the method worked well, with most of the birds scared away within 20 minutes, and treatment over consecutive evenings caused the temporary desertion of the roost. Cormorants appeared to be particularly sensitive to laser light. Similar results were obtained at a cormorant night-roost in the region of the Dombes, France. After using a laser gun for two nights, the night-roost was deserted for a week (Broyer 1995, cited in Boudewijn and Dirksen 1996).

Successful results were also achieved in America using the laser gun ‘Avian Dissuader’, costing US$900. The laser treatment cleared roosting crows from the Capitol complex within an hour (State Capitol Bureau 2001). The long-term success is not reported.

In Britain, laser light was tested against two cormorant night roosts (McKay et al 1999). At one site cormorant numbers were significantly reduced after seven consecutive days use and bird numbers did not return to normal until between 12 and 30 days later. At the other site, the laser gun was less effective with some birds failing to leave the roost. The laser also deterred goosanders though the effect lasted less than one day.

The laser gun used in this British study was a purpose-built device produced by Desman S.A.R.L. of France and cost £4633 (at 1996 prices). Training in its use by the manufacturer cost another £1056. There were some questions over safety of the device because although the company state that the laser was safe, they also advised that it should not be pointed at humans. The device has been tested for safety at the UK Government’s Defence Evaluation and Research Agency (DERA), Farnborough, England and found to be safe if it was not pointed at an unprotected eye within a distance of 155 m (McKay et al. 1999). The safe distance was considerably reduced if viewed with binoculars.

The use of lasers can be an effective method of bird scaring, although there is some evidence to suggest some birds are laser-resistant (McKay et al. 1999). The equipment is expensive and specialized training is required, adding to the costs. As the effectiveness of the laser decreases with increasing light levels, it is likely to be most effective at dawn and dusk. Its usefulness may therefore be confined to night time roosts and feeding sites at dawn. As it is operated manually user costs at anti-social hours must also be taken into consideration. However, the ability to ‘target’ specific problem species may be useful at certain sites, such as areas of conservation interest, where disturbance of non-target species may be kept to a minimum.


Other laser-related dispersal products and information


Note: We do not necessarily recommend consumer use of these products or techniques, especially since aviation officials are sensitive to unsupervised use of lasers in airspace. The items below are listed for informational purposes.

  • An Australian company makes the Bird Gard laser gun, intended specifically to scatter birds. The user manual states it has 50 mW output, 650 nm (red), with a large 50 mm beam at the aperture. The Nominal Ocular Hazard Distance is 300 feet (90 m) which means the direct beam should not go into a person’s eye if they are within 300 feet of the laser gun. Species listed for this laser gun include black duck, cormorant, heron, ibis, pigeon, sparrow, swallow and wood duck. The Bird Gard laser gun webpage has a short video showing birds being dispersed by the red laser light.

  • A December 2002 U.S. Department of Agriculture publication discusses “Evaluation of lasers to disperse American Crows … from urban night roosts.” The University of California at Davis conducted a study over four nights. From 50% to 99% of crows did disperse due to laser light being aimed at them. But they came back within 15 minutes. Even after four nights of laser harassment, the crows still returned to their roosts. The authors wrote “The laser beam produced a startle reaction comparable to that produced by a sudden, loud noise, but imparted no threat sufficient to cause desertion of a roost.… we do not recommend lasers as a stand-alone dispersal tool at urban crow roosts based on the poor results…” The study did imply that other species might react differently: “Little is known about the reaction of most North American bird species to laser light or the most effective application of lasers for different species and locations.” The study also noted possible problems with aircraft. It reported on one 2000 study where after two hours of lasing a tree, crows stayed off for one night: “However, further treatment on successive nights to determine if birds would abandon roosts could not be undertaken because of aircraft traffic at an adjacent airfield.”

  • A January 2002 article in the Journal of Wildlife Management, “Lasers as Nonlethal Avian Repellents”, contends that lasers may prove useful but more research is needed on the powers, wavelength, etc. that are most effective against various species. The study does report some controlled tests in which it seems most birds returned within 20 minutes to the laser-treated area.

  • A February 2002 review of lasers for dispersing birds around airports, presented at a 2002 FAA conference, concludes that “low- to moderate-power, long-wavelength lasers (630- 650 nm) provide an effective means of dispersing some ‘problem’ bird species under low-light conditions, while presenting no threat to the animal or the environment.” (The FAA presentation was not peer-reviewed; it represented work that was published in the January 2002 article listed immediately above.)

  • A 2006 study of deer found that lasers would not be effective for wildlife management. Results showed that while deer could see the laser spots, they “appeared to be more curious than frightened. We conclude that laser light has no potential as a nonlethal management option for reducing deer damage.”

  • An August 2013 news story briefly describes how the manager of a golf course uses a laser pointer to disturb nuisance geese that soil the course: “They would come in every morning at 5 a.m. and wake me up. I would go out with a laser and shine it across the lake, and they were gone.”

  • An August 2017 news story also has a brief description and photo of a laser designator being used at Singapore’s Changi Airport as a last resort to scatter birds. (Normally they use loud sounds, broadcast twice a day.)

Pic 2017-08-20 at 10.56.49 AM 50pct




Thanks to Dr. Mathieu Gauthier for sending in a correction to this page on 2/23/2012.