TECHNIQUE

Hazing - Scarecrows etc.

Summary Information
Type of technique Health & Management / Disease Investigation & Control / Environmental and Population Management / Techniques:
Synonyms and Keywords Human effigies, predator models, strobe lights, balloons, flags, other visual deterrents.
Description Visual deterrents may take a variety of forms 

Human effigies and predator models:

  • Scarecrows or effigies may be constructed to varying degrees of realism, from e.g. simple fluorescent orange plastic bags hung on poles to human-shaped effigies complete with facial features. (D10, D211.AppIIIc.w12)
  • Depending on their construction, they may move in the wind. (D10)
  • Predator models may be constructed from a variety of materials. (D10)
  • Versions are available which are inflatable and pop-up periodically. (D211.AppIIIc.w12)

Balloons:

  • All-weather helium balloons of 50 to 75 cm (20 to 30 inches) diameter; (D135.3.w3)
  • Balloons are not fully inflated, to reduce wind resistance stress. (D135.3.w3)
  • Tether to an object on land or to a floating object in water, and away from obstacles such as trees which could puncture the balloon. (D135.3.w3)
  • Use at intervals of at least 200 yards (183 m), on strong monofilament (22 kg/48 lb or greater breaking strength) lines 12 to 23 m (40 to 75 feet) long. (D135.3.w3)
  • Place some balloons higher to discourage birds from flying over the area. (D135.3.w3)
  • Mpve every three to five days to reduce habituation. (D211.AppIIIc.w12)
  • Balloons may be painted with large eyes. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

Flags:

  • Attach sheets of black plastic (60 by 90 cm, two foot by three foot) to 1.2 m (four foot) stakes;
    • Black or white bin bags (trash bags) may be used as flags;
    • Mylar car dealership flags can be used.
  • Driving the stakes into the ground at an angle so the flags move in light winds;
  • Place every 30 to 60 m (100 to 200 feet) on land, or on buoys on water. 
  • May be used together with propane cannon.

(D135.3.w3, D160.App3.w11, D211.AppIIIc.w12)

Kites:

  • These may be painted with large eyes, or made in the shape of predatory birds. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

Reflectors / mirrors / Reflective tape:

  • Attach aluminium or tinfoil plates to a line, over land or over water. 
  • Can be used in association with lights. 
  • Handheld mirrors can also be used. 
  • Mylar reflective tape (silver and red coated) is twisted and strung between support posts (lengths up to 25 ft) or short lengths are tied to individual poles, to reflect sunlight (flashes produced). 
    • In windy conditions the tape also vibrates with a humming noise, or crackles as it flaps in the wind. 

(D135.3.w3, D160.App3.w11, D211.AppIIIc.w12)

Lights, including Strobes:

  • Strobes, barricade lights, searchlights and revolving lights may be used. (D135.3.w3, D160.App3.w11)
  • Lights should be used in conjunction with other hazing devices such as propane cannon or pyrotechnics. (D135.3.w3, D160.App3.w11)
  • Strobe lights may be used in conjunction with scarecrows for use at night. (D10)
    • Red strobe lights with a flashing rate of six to 12 per second may be most effective. (D10)

May be used in conjunction with acoustic hazing devices. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

Appropriate Use (?) May be used e.g. in agricultural fields to reduce depredations by grazing waterfowl, or to deter birds from using hazardous areas. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)
  • May significantly reduce the number of birds using an area. (D10)
  • May be mounted on rafts for use on water. (D10)
  • May be used in conjunction with other deterrent devices such as propane cannons. (D10)
  • May be more effective if alternate sites are available nearby. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

Scarecrows and predator models:

  • Scarecrows (human effigies) have been shown to have considerable efficacy in reducing use of agricultural fields by geese, (D10, J59.18.w1) and in deterring waterfowl, particularly Aythya spp. diving ducks, and shorebirds from entering normal and polluted ponds. (J40.44.w2)
  • Are most likely to be effective "if they appear lifelike, have motion, are frequently repositioned, and are used in combination with loud sounds or recorded distress calls." (D160.App3.w11)
  • Scarecrows in fluorescent orange (for high visibility), on a boat, together with lights and a propane cannon, have been shown to have a deterrent effect on birds but did not deter all birds. (D10)
  • May be useful at loafing and roosting sites in association with other hazing techniques. (D211.AppIIIc.w12)
  • Easily put into place. (D10, D160.App3.w11)
  • Easy and rapid to move. (D10, D160.App3.w11)
  • May be used near human-populated areas: no auditory disturbance. (D10; D160.App3.w11)
  • Wind and rain do not seriously reduce effective range. (D10; D160.App3.w11)

Flags:

  • May be particularly effective against waterfowl. (D135.3.w3)
  • These have been shown to have considerable efficacy in reducing use of agricultural fields by geese. (J59.18.w1)

Reflectors / mirrors / Reflective tape:

  • Tape is best used as a deterent in limited specific areas such as a breakwater or mudflat. (D211.AppIIIc.w12)

Balloons:

  • May deter birds from a relatively wide area (larger than that produced by ground-sited visual deterrents). (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

Lights:

  • May have a partial effect to deter waterfowl at night. (D135.3.w3, D160.App3.w11)
Notes
  • More realistic models (e.g. human effigies with facial features) may be most effective. (D10)
  • More effective if moved frequently (e.g. every two to three days). (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)
Complications/ Limitations / Risk Scarecrows and Predator models:
  • Only useful in daytime, unless combined with audible deterrents or used with lights. (D10, D160.App3.w11, J40.44.w2)
  • Relatively rapid habituation by birds (a few days). (D10, D160.App3.w11)
  • May be less effective on resident birds than on transient populations. (J40.44.w2)
  • Short effective range, e.g. 100 metres, or four to eight hectares. (D10, D160.App3.w11)
  • Not effective if the topography of the land blocks them from view. (J59.18.w1)
  • Mainly used to deter birds on land. (D10)
  • In one study, a predator model was found to be less effective than was a human effigy at deterring waterbirds from pools. (J40.44.w2)
  • In some areas (e.g. public parks) visual scaring devices may be considered unsightly, may interfere with use of the area by humans, and may be at risk of theft. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)
  • Some time may be required to construct effigies initially. (D211.AppIIIc.w12)

Kites and balloons

  • May not fly well in heavy rain or very strong winds. 
  • Balloons need to be refilled with helium every three to five days. (D211.AppIIIc.w12)
  • May need to be re-set if the wind direction changes. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)
  • May be vandalised (D211.AppIIIc.w12)
  • Habituation may be rapid. (D211.AppIIIc.w12)

Reflectors / mirrors / Reflective tape:

  • Effectiveness varies with bird species. (D211.AppIIIc.w12)
  • May attract some birds instead of deterring them. (D160.App3.w11)
  • Habituation occurs; this may be reduced by placing and removing the devices periodically. (D211.AppIIIc.w12)
  • Not effective at night. (D160.App3.w11)
  • Less effective in the absence of wind. (D211.AppIIIc.w12)

Lights, including strobes:

  • May attract some birds, particularly in conditions of rain, fog or heavy cloud. (D10, D135.3.w3, D160.App3.w11, D211.AppIIIc.w12)

Flags:

  • These are only effective in daytime and birds may become habituated to them relatively rapidly. (D10, D160.App3.w11)
Equipment / Chemicals required and Suppliers
  • Appropriate materials e.g. clothing, bags, cloth etc. and frames to hang effigies on.
  • Balloons and monofilament line.
  • Plastic sheeting and stakes for flags.
  • Reflective materials.
  • Lights.
  • Strobe lights, if night-time use required. 
  • Rafts if use on water required. 
Expertise level / Ease of Use
  • Simple to construct and deploy.
Cost/ Availability
  • Inexpensive; scarecrows and predator models may be constructed with readily-available materials, balloons and flags are cheap and readily available. (D10, D160.App3.w11, J59.18.w1)
  • Reflective objects are inexpensive. (D160.App3.w11)
  • Lights are inexpensive. (D160.App3.w11)
  • Increased cost if strobe lights also used. (D10)
Legal and Ethical Considerations
  • May be used in human-populated areas.
  • Risk of lights attracting rather than repelling some birds, particularly in conditions of rain, fog or heavy cloud. (D10, D135.3.w3, D160.App3.w11)
Author Dr Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee --
References D10, D135.3.w3, D160.App3.w11, D211.AppIIIc.w12, J59.18.w1, (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

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