• A device for harassing animals in which propane gas is exploded within the "cannon" by the striking of a flint at an adjustable timed interval. The noise produced is directional, shot-gun like and loud (approximately 120dB).
  • The device consists of separate pressure and combustion chambers, an ignition mechanism, and a barrel to aim and magnify the blast, together with bottled supply of gas. (D135.3.w3, D160.App3.w11, D211.AppIIIc.w12)
  • A bellows is slowly filled with propane gas from the tank. The gas is then rapidly transferred to the firing chamber and ignited by a spark. (D160.App3.w11)
  • The device is preferably set above surrounding vegetation or landscape features in order to maximise their effective range. (D10)
  • In windy conditions, a barrier such as a large piece of plywood is placed to protect the rear part of the cannon, housing the ignitor. (D211.AppIIIc.w12)
• Some devices can be set to fire in varying directions.
• Some can be set to fire at varying intervals (from less than a minute to 30 minutes). (D160.App3.w11); from three to 30 minutes (D211.AppIIIc.w12).
  • When several exploders are used they should be set with staggered firing intervals. (D135.3.w3)
  • Some exploders can be set to fire at random intervals and in a different direction for each blast. (D160.App3.w11)
• The blast intensity may be adjustable.
• The period of operation may be adjustable. 

(B36.4.w4, B127.12.w12, D135.3.w3, D160.App3.w11, D211.AppIIIc.w12)

• May be used in a variety of settings including airports, agricultural areas, landfill sites and even on water (on e.g. an anchored raft or a drifting boat). (D10, D160.App3.w11)
• May be particularly effective to deter birds e.g. from oil which is in a confined area. (D10)
• Effective against a wide range of bird species. (D10)
• Effective day and night - shown to be effective in dispersing waterfowl feeding at night. (D10, D160.App3.w11)
  • Particularly appropriate for nightime use (since personnel are not required once the device is set) in areas without human populations. (D10)
• Particularly effective against dabbling ducks and geese. (D10, D160.App3.w11)
• Most effective against migrating and hunted species which associate loud noises with danger. (D135.3.w3)
• Can be mobilised and moved rapidly. (D160.App3.w11)
• Rapid initial effect. (D10)
• May be effective on reasonable-sized areas (200 to 1,000m, or 30 to 50 hectares). (D10, D160.App3.w11)
• Low manpower requirement for both deployment and operation (e.g. daily check). (B36.4.w4, D160.App3.w11, D211.AppIIIc.w12)
• Inexpensive. (D10)
• Low maintenance requirement. (D10)

• May be set to operate for about two weeks before refuelling is required. (D10, D160.App3.w11)
• More effective if multiple exploders are used in an area. (D135.3.w3)
• More effective if moved every one to four days - even movement by 15 to18 m (50 to 60 feet) may be sufficient. (D135.3.w3)
• More effective if used together with other hazing methods. (D211.AppIIIc.w12)

• Rapid habituation - usually two to three days if used as sole means of hazing, may be as low as a few hours for some species. (D10, D160.App3.w11)
  • Habituation within a week noted when a propane cannon was used for hazing ducks from an island (30 m long) that was a focus for botulism. (B127.12.w12)
  • Reduced habituation if the cannon are moved every two or three days. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)
• Less effective against resident, well established species. (D135.3.w3)
• Not very effective against some species (e.g. loons Gavia spp., grebes, gulls, coots, many shorebirds). (D10, D160.App3.w11)
• Significantly reduced effective range in foggy or windy conditions. (D10, D160.App3.w11)
• Difficult to install and operate in bad weather conditions and on open water. (D10, D160.App3.w11)
• In areas to which the public have access they may be subject to vandalism or theft. (P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)

• Propane cannon.
• Propane gas.
  • A 5 lb propane tank provides sufficient gas for about 12,000 explosions, which will give one explosion every four minutes for two weeks. (D211.AppIIIc.w12)
• Raft/boat for use on water. (D10)

• Simple to install and operate. (D10)
• Potentially dangerous. Should only be used by trained personnel. (D160.App3.w11)

• Inexpensive to buy and maintain. (D160.App3.w11)
• Widely available. (D160.App3.w11)

• May be disturbing e.g. near populated areas (to residents) and to oil spill responders. (D10, D160.App3.w11, P12.10 - The Management of Problems caused by Canada Geese - A Guide to Best Practice)