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BackgroundHealth, safety, and property damage

associated with birds are often a source ofconcern. At the same time, the public(especially in the U.S.) wants non-lethal,non-injurious, and environmentally benignsolutions to such problems. In situationswhere physical barriers, netting, andalarming agents or devices are notpractical or are offensive to the localhuman population; there are currently fewor no other non-lethal options for controlof pest birds. Sight is well developed inmost birds, including most common pestspecies. Several trials of directed orreflected light as a bird control tool havebeen reported4, 9, 10.

Recent research by the U.S.Department of Agriculture’s NationalWildlife Research Center has shown thatrelatively low-power, long-wavelengthlasers — 630-650 nm, producing a “red”beam — can effectively disperse some pestbird species under low-light conditions,while presenting no threat to the birds orthe environment. For example, double-

crested cormorants and Canada geese (Fig1.), have shown extreme avoidance of thereflected “spot” at the end of such redlaser beams. Other birds, includingwaterfowl, wading birds, gulls (Fig 3.),vultures (Fig 4.), and crows (Fig 5.), havealso avoided red laser beam “spots” infield trials, but responses depended on thesituation and species3, 5, 8.

The three main domestic pest birdspecies: Pigeons (Fig 7.), starlings (Fig 8.),and English sparrows (Fig 9.), are lessreadily repelled or dispersed by thistechnique. Pigeons and starlings can beforced out of roosting sites, but it mayrequire numerous sessions (the periodwhen a PMP disturbs the birds on theirroost for a short period of time soon afterdusk) repeated over several consecutivedays. The lower power levels, directivity,accuracy over distance, and silence of laserdevices make them relatively safe,effective species-specific alternatives topyrotechnics, shotguns, loud recordedsounds and other traditional bird dispersaltools.

Insert this update into the NPMA Pest Management Library, which can bepurchased from the Resource Center. phone: 703-573-8330 fax: 703-573-4116

UpdateN P M A L I B R A R Y U P D A T E

Using Lasers to Disperse Birds

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Avian DispersalThe use of lasers takes advantage of a

major sensory pathway of birds (i.e.,vision). The repellent or dispersal effect ofa laser, targeting birds, is due to theintense, coherent, single wavelength oflight, which can definitely cause changesin their behavior. These behaviors includemoving away from the “spot;” becomingagitated, and, in some cases, physiologicalchanges.

Birds’ responses are greatest underconditions of low light (dusk throughdawn, or similar conditions) and when thereflected spot of a laser is directed ontostructures or trees very near the roostingbirds. Moving the spot around near thebirds, especially toward them sometimes,usually increases their response. Somespecies of birds have been effectivelycaused to disperse by shining diffuse light(i.e., a q-beam) on and near them, butmost birds quickly get used to it, and theeffectiveness decreases quickly as distancefrom the light source increases. Nohabituation to the red lasers has beenobserved so far in repeated field trials6, 7.

Laser Classification and SafetyThe eyes of birds generally filter the

most damaging radiation (e.g., short-wavelength radiation from the sun). Intests conducted with double-crestedcormorants exposed to a relatively low-power Class-IIIb laser (see laserclassification below) at a distance of onemeter, no ocular damage was noted11.Unlike birds’ eyes, human eyes, except forthe blink reflex, are essentiallyunprotected from thermal damage toretinal tissue which can be caused byconcentrated laser radiation. Standardsand guidelines have been established forlaser classification and use, and foradequate protective devices andpractices1, 2, 12.

Laser classification is determined bythe amount of radiant power within a 7-mm aperture at a distance of 20 cm. Class Iincludes very low-power devices, whichemit only a very small point of light. Class-II includes visible lasers that emit a radiantpower of less than one milliWatt (<1 mW)as a low-power continuous wave (e.g.,supermarket checkout scanners).

Class IIIa includes most laser pointersused by speakers, which emit a weak beam(usually < 5 mW). Class-IIIb includesmoderate-power lasers (5-500 mW;continuous wave) that are generally notcapable of producing a hazardous diffusereflection, except when someoneintentionally stares at the source devicevery close to the diffuser (i.e., the laserhead). Lasers tested by the NWRC include:the AC-powered, Class-IIIb, 10 mW, He-Ne,633 nm High-Performance Uniphase™laser; the Class-IIIb, 5 mW, He-Ne, 633 nmDesman™ laser, model FL R 005 (Fig 10.);and the Class-II, battery-powered, 68 mW,650 nm, diode Laser Dissuader™ (Fig 11.).Wildlife Services biologists currently usethe Desman laser and Laser Dissuader inoperational programs.

Information on regulatory authorityand safety specifications for laser use inbird management has been compiled inreference 7 (below), available from theNWRC library at: 970-266-6017.

Safe and successful bird dispersal bylasers in a variety of settings depends onindividual site conditions, particularly inurban areas. Specific, current requirementsfor laser operations and PPE in the U.S. isavailable on the OSHA website:www.osha.gov (also, see references 1 and2, below). Any laser operator mustconsider background, range of the beam,and potential reflections. The nominal

Figure 7

hazard zone (NHZ) is 12.72 m for theDesman, when considering the humanblink reflex (the Dissuader is considered“eye safe” for incidental exposure).

For a 10 second exposure, the NHZ is 44and 25 m for the Desman and Dissuaderlasers, respectively. Lasers should not beaimed towards people, roads, or aircraft.Laser dispersal of birds on airports isprohibited without prior approval of theU.S. Federal Aviation Administration(FAA).

Laser AvailabilityThe Uniphase laser has been used only

under controlled experimental conditions,with no field application. The Desmanlaser was developed specifically for birddispersal and is marketed by Reed-JosephInternational Co. for approximately $7,500

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U.S. The Laser Dissuader, developed as athreat deterrent security device for U.S.military and law enforcement agencies, isconsidered (relatively) safe for use againsthumans. It has been produced, and iscurrently marketed by Science andEngineering Associates (SEA), Inc., forslightly less than $1,000 U.S. They havealso partnered with Avian Systems todevelop a product that incorporates aversion of the Dissuader and a Dopplerradar to produce site-specific, “on-demand” targeting of problem birds.Currently, WS biologists in Mississippi usethe Desman laser to disperse double-crested cormorants from night roosts nearcatfish production sites. The NWRCcontinues to evaluate laser technology todisperse a variety of bird species underdifferent conflict situations.

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References:1. ANSI Z87.1-1989: Practice for

Occupational and Educational Eye andFace Protection. www.ansi.org

2. ANSI Z136.1-1999: American NationalStandard for Safe Use of Lasers.www.ansi.org

3. Blackwell, B., G. Bernhardt, and R.Dolbeer. 2000. Wildlife controlmethods for airports (Task 3).Experiment 1: Lasers as non-lethalavian repellents. Interim reportsubmitted to DOT/FAA, William J.Hughes Technical Center by USDA/WS/NWRC. Available from NWRC FieldStation, Sandusky, OH.

4. Blackwell, B. 2002. Understandingavian vision: the key to using light inbird management., Proc., 20th Vert.Pest Mgt. Conf. (in press).

5. Blackwell, B., G. Bernhardt, and R.Dolbeer. 2002. Lasers as non-lethalavian repellents. J. Wildl. Mgt. 66(1):250-258.

6. Dennis, J., J. Harrison, W. Wallace, R.Thomas and S. Cora. 1999. Visualeffects assessment of the Dissuader™laser illuminator. U.S. Air Force Res.Lab. Rept. AFRL-HE-BR-TR-1999-0179.

7. Glahn, J., and B. Blackwell. 2001.Safety guidelines for using theDesman™ laser and Dissuader™ laserto disperse double-crested cormorantsand other birds. USDA, APHIS, WildlifeServices, National Wildlife Res. Ctr.Available from NWRC Field Stations atStarkville, MS, and Sandusky, OH.

8. Glahn, J., G. Ellis, P. Fiornelli, and B.Dorr. 2000. Evaluation of moderate-and low- powered lasers for dispersingdouble-crested cormorants from theirnight roosts. Proc., 9th Wildl. DamageMgt. Conf. 9. (in press).

9. Lustick, S. 1973. The effect of intenselight on bird behavior and physiology.Proc. 6th Bird Contr. Seminar. 171-186.

10. Seamans, T., C. Lovell, r. Dolbeer. AndJ. Cepek. 2001. Evaluation of mirrors todeter nesting starlings. Wildl. Soc. Bull.29(4): 1061-1066.

11. Soucaze-Soudat, J. and M. Ferri. 1997.A means of scaring birds: the lasergun, description and applications tocormorants and other birds.Desman™S.A.R.L, France incooperation with the office of WildlifeProtection and Regulation of Huntingand Fishing, Modena Province RegioneEmilia Romagna, Italy.

12. Univ. of Pennsylvania. 1993. LaserSafety Manual. Univ. of Pennsylvania,Phila., PA.

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