Bird scarer
Encyclopedia
A bird scarer is any one of a number devices designed to scare birds, usually employed by farmer
s to dissuade birds from eating recently planted arable crops.
They are also used on airfields to prevent birds accumulating near runways and causing a potential hazard to jet aircraft.
in the shape of a human figure. The scarecrow idea has been built upon numerous times, and not all visual scare devices are shaped like humans. The "Flashman Birdscarer," Iridescent tape, "TerrorEyes" balloons, and other visual deterrents are all built on the idea of visually scaring birds. This method doesn't work so well with all species, considering that some species frequently perch on scarecrows.
Many species of bird are also naturally afraid of predators such as birds of prey. "Hawk Kites" are designed to fly from poles in the wind and hover above the field to be protected. They are shaped to match the sillouette of a bird of prey.
birdscarer is a lighter-than-air combination of a helium balloon and a kite. Helikites fly up to 200ft in the air with or without wind. Although they do not look like hawks, they fly and hover high in the sky behaving like birds of prey. Helikites successfully exploit bird pests' instinctive fear of hawks and can reliably protect large areas of farmland.
s can be an effective method of bird scaring, although there is some evidence to suggest some birds are "laser-resistant." The equipment is expensive and specialised 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.
The method relies on Birds being startled by the strong contrast
between the ambient light and the laser beam. During low light conditions this technique is very selective and can be attuned to frequencies and wavelengths that individual bird species don't like, but at night the light beam is visible over a large distance and can cause widespread (non-species specific) disturbance.
Balloons are an inexpensive deterrent. However, this method relies on the movement of balloons, which is something that birds can become used to.
The addition of eye illustrations on the balloons has been shown to increase this method's effectiveness as it combats the birds' ability to adapt. Commercially available "scare-eye" balloons have holographic eyes that follow birds wherever they go. The long-term effectiveness of this method can be increased by periodically moving the placement of the scare devices.
In the United Kingdom the use of balloons is subject to approval from the Civil Aviation Authority
, especially around airfields.
Towards the end of the 20th century, one of the most popular types of bird scarer used by farmers in Europe and America is the propane
powered gas gun which produces a periodic loud explosion
. The audible bang can reach volumes in excess of 150 decibel
s near the gun.
One of the problems with gas gun scarers is that the loud bangs can also irritate people living on nearby properties, or other people using the countryside. Also, birds adapt quickly to any sound that does not randomize its magnitude, pitch, or time interval. Propane cannons become ineffective after a short while.
. The sound is designed to be too high pitched for people to hear, but audible to most birds. This has the advantage to preventing disturbance to neighbouring households. However, these can be heard by some people, particularly females and the young, and although this ability is generally lost with age it can cause discomfort and even headaches for those in proximity who have sensitive high-range hearing. Certain Ornithologists claim that many "pest birds" have a hearing sensitivity similar to that of humans and that the efficiency of ultrasonic bird scarers is not scientifically possible.
Cartridges are projected from a shotgun with a range of 45-90m, or pistol (range approximately 25m), and then explode. Bird scaring cartridges can produce noise levels of up to 160dB at varying ranges but both the cartridges and the gun require a firearms certificate in some countries.
Pyrotechnics have proved effective in dispersing birds at airports, landfill sites, agricultural crops and aquaculture facilities. At airports in the UK, shellcrackers fired from a modified pistol are the most common means of dispersing birds, as they allow the bird controller to have some directional control over birds in flight, so they can be steered away from runways.
However, as with all similar noises, there is a high risk of birds becoming used to any pyrotechnics or cartridge explosions.
s and swallow
s.
In 1999 Southwest Florida International Airport
became the first commercial airport in the world to employ a border collie in an airfield wildlife control programme. After the use of the collie, numbers and species of birds on the airport declined and most birds that remained congregated in a drainage ditch away from the runway. The number of bird strike
s dropped to zero compared to 13 for the same period the previous year. Several other airports and airbases have now started similar programmes.
At Dover Air Force Base
, Delaware, bird strike damage to aircraft caused by birds has been reduced from an average of US $600,000 / year for the proceeding two years to US$24 000/year after the initiation of a bird control programme that included the use of border collies.
The problem with border collies, however, is that the underlying problem of any bird infestation is not being solved: the birds find the area attractive. The birds temporarily find the area unattractive when the dog is there, but the second the dog leaves the birds will probably come back. This creates a situation in which the dogs must be consistently employed as long as the area is to be kept free of birds, resulting in high and persistent labor costs.
s and hawk
s as predators, so their presence in the area encourages problem species to disperse. The natural reaction of most prey species is to form a flock and attempt to fly above the falcon. If this fails, they will attempt to fly for cover and leave the area.
have been used to scare or 'haze' bird pests since the early 1980s, mainly over airfields, but have also been used over agricultural areas, fisheries and landfill sites. This method has been shown to be very effective and birds habituate more slowly to a treatment in which they are being actively hazed. At Whiteman Air Force Base
, Missouri, balsa wood radio-controlled aircraft are one of the primary bird harassment methods used to keep the airfield clear of raptors and other large birds, and they have also proved effective at dispersing the base’s redwing blackbird roost.
Farmer
A farmer is a person engaged in agriculture, who raises living organisms for food or raw materials, generally including livestock husbandry and growing crops, such as produce and grain...
s to dissuade birds from eating recently planted arable crops.
They are also used on airfields to prevent birds accumulating near runways and causing a potential hazard to jet aircraft.
Scarecrow
One of the oldest designs of bird scarer is the scarecrowScarecrow
A scarecrow is, essentially, a decoy, though traditionally, a human figure dressed in old clothes and placed in fields by farmers to discourage birds such as crows or sparrows from disturbing and feeding on recently cast seed and growing crops.-History:In Kojiki, the oldest surviving book in Japan...
in the shape of a human figure. The scarecrow idea has been built upon numerous times, and not all visual scare devices are shaped like humans. The "Flashman Birdscarer," Iridescent tape, "TerrorEyes" balloons, and other visual deterrents are all built on the idea of visually scaring birds. This method doesn't work so well with all species, considering that some species frequently perch on scarecrows.
Hawk Kite
Helikites
The HelikiteHelikite
The names Helikite and Helikites, are Allsopp's Registered Trade Marks relating to a new type of kite-style aerostat designed and patented by Sandy Allsopp in England....
birdscarer is a lighter-than-air combination of a helium balloon and a kite. Helikites fly up to 200ft in the air with or without wind. Although they do not look like hawks, they fly and hover high in the sky behaving like birds of prey. Helikites successfully exploit bird pests' instinctive fear of hawks and can reliably protect large areas of farmland.
Lasers
The use of laserLaser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
s can be an effective method of bird scaring, although there is some evidence to suggest some birds are "laser-resistant." The equipment is expensive and specialised training is required, adding to the costs. As the effectiveness of the laser decreases with increasing light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
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.
The method relies on Birds being startled by the strong contrast
Contrast (vision)
Contrast is the difference in visual properties that makes an object distinguishable from other objects and the background. In visual perception of the real world, contrast is determined by the difference in the color and brightness of the object and other objects within the same field of view...
between the ambient light and the laser beam. During low light conditions this technique is very selective and can be attuned to frequencies and wavelengths that individual bird species don't like, but at night the light beam is visible over a large distance and can cause widespread (non-species specific) disturbance.
Dead Birds
The use of model or actual dead birds is used to signal danger to others. Initially birds often approach the corpse but usually leave when they see the unnatural position of the bird. This approach has been frequently used in attempts to deter gulls from airports.Balloons
The addition of eye illustrations on the balloons has been shown to increase this method's effectiveness as it combats the birds' ability to adapt. Commercially available "scare-eye" balloons have holographic eyes that follow birds wherever they go. The long-term effectiveness of this method can be increased by periodically moving the placement of the scare devices.
In the United Kingdom the use of balloons is subject to approval from the Civil Aviation Authority
United Kingdom Civil Aviation Authority
The Civil Aviation Authority is the public corporation which oversees and regulates all aspects of aviation in the United Kingdom. The CAA head office is located in the CAA House on Kingsway in Holborn, London Borough of Camden...
, especially around airfields.
Propane Cannons (propane gas guns)
Propane
Propane is a three-carbon alkane with the molecular formula , normally a gas, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel for engines, oxy-gas torches, barbecues, portable stoves, and residential central...
powered gas gun which produces a periodic loud explosion
Explosion
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. An explosion creates a shock wave. If the shock wave is a supersonic detonation, then the source of the blast is called a "high explosive"...
. The audible bang can reach volumes in excess of 150 decibel
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
s near the gun.
One of the problems with gas gun scarers is that the loud bangs can also irritate people living on nearby properties, or other people using the countryside. Also, birds adapt quickly to any sound that does not randomize its magnitude, pitch, or time interval. Propane cannons become ineffective after a short while.
Electronic Repellers (digitally recorded distress sounds)
One of the most effective sonic repellers on the market. Usually consisting of a central unit and several speakers, the system emits the distress calls, and, if it is a quality product, calls of predators of the target species as well. Effective emitters randomize pitch, magnitude, time interval, sound sequence and other factors to prevent birds from getting used to them.Ultrasonic scarers
Ultrasonic scarers are electronic devices that produce high pitch emissions ultrasoundUltrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
. The sound is designed to be too high pitched for people to hear, but audible to most birds. This has the advantage to preventing disturbance to neighbouring households. However, these can be heard by some people, particularly females and the young, and although this ability is generally lost with age it can cause discomfort and even headaches for those in proximity who have sensitive high-range hearing. Certain Ornithologists claim that many "pest birds" have a hearing sensitivity similar to that of humans and that the efficiency of ultrasonic bird scarers is not scientifically possible.
Cartridge scarers
Cartridge scarers include a wide variety of noise-producing cartridges usually fired from rockets or rope bangers, or on aerodromes from modified pistols or shotguns, which produce a loud bang and emit flashes of light. They include shellcrackers, screamer shells and whistling projectiles, exploding projectiles, bird bangers and flares.Cartridges are projected from a shotgun with a range of 45-90m, or pistol (range approximately 25m), and then explode. Bird scaring cartridges can produce noise levels of up to 160dB at varying ranges but both the cartridges and the gun require a firearms certificate in some countries.
Pyrotechnics have proved effective in dispersing birds at airports, landfill sites, agricultural crops and aquaculture facilities. At airports in the UK, shellcrackers fired from a modified pistol are the most common means of dispersing birds, as they allow the bird controller to have some directional control over birds in flight, so they can be steered away from runways.
However, as with all similar noises, there is a high risk of birds becoming used to any pyrotechnics or cartridge explosions.
Dogs
The control of birds and other wildlife such as deer through harassment by trained border collies has been used at aerodromes, golf courses and agricultural land. The dogs represent an actual threat, and so elicit flight reactions. Habituation is unlikely as they can continually pursue and change their behaviour. Border collies are used as they are working dogs bred to herd animals and to avoid attack, and they respond well to whistle and verbal commands. A single border collie and its handler can keep an area of approximately 50 square kilometres free of larger birds and wildlife and although they are effective at deterring ground foraging birds such as waders and wildfowl, they are not so useful for species that spend most of their time flying or perching, such as raptorBird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
s and swallow
Swallow
The swallows and martins are a group of passerine birds in the family Hirundinidae which are characterised by their adaptation to aerial feeding...
s.
In 1999 Southwest Florida International Airport
Southwest Florida International Airport
-Statistics:-Accidents and incidents:* November 28, 2007 - A single-engine fixed wing aircraft crashed about 9:20 a.m. one mile west of Runway 6. The crash killed the pilot...
became the first commercial airport in the world to employ a border collie in an airfield wildlife control programme. After the use of the collie, numbers and species of birds on the airport declined and most birds that remained congregated in a drainage ditch away from the runway. The number of bird strike
Bird strike
A bird strike—sometimes called birdstrike, avian ingestion , bird hit, or BASH —is a collision between an airborne animal and a man-made vehicle, especially aircraft...
s dropped to zero compared to 13 for the same period the previous year. Several other airports and airbases have now started similar programmes.
At Dover Air Force Base
Dover Air Force Base
Dover Air Force Base or Dover AFB is a United States Air Force base located two miles southeast of the city of Dover, Delaware.-Units:...
, Delaware, bird strike damage to aircraft caused by birds has been reduced from an average of US $600,000 / year for the proceeding two years to US$24 000/year after the initiation of a bird control programme that included the use of border collies.
The problem with border collies, however, is that the underlying problem of any bird infestation is not being solved: the birds find the area attractive. The birds temporarily find the area unattractive when the dog is there, but the second the dog leaves the birds will probably come back. This creates a situation in which the dogs must be consistently employed as long as the area is to be kept free of birds, resulting in high and persistent labor costs.
Predators
The success of this method of bird control is based on the fact that many birds have a natural fear of falconFalcon
A falcon is any species of raptor in the genus Falco. The genus contains 37 species, widely distributed throughout Europe, Asia, and North America....
s and hawk
Hawk
The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...
s as predators, so their presence in the area encourages problem species to disperse. The natural reaction of most prey species is to form a flock and attempt to fly above the falcon. If this fails, they will attempt to fly for cover and leave the area.
Radio controlled aircraft
Radio-controlled model aircraftModel aircraft
Model aircraft are flying or non-flying models of existing or imaginary aircraft using a variety of materials including plastic, diecast metal, polystyrene, balsa wood, foam and fibreglass...
have been used to scare or 'haze' bird pests since the early 1980s, mainly over airfields, but have also been used over agricultural areas, fisheries and landfill sites. This method has been shown to be very effective and birds habituate more slowly to a treatment in which they are being actively hazed. At Whiteman Air Force Base
Whiteman Air Force Base
Whiteman Air Force Base is a United States Air Force base located approximately south of Knob Noster, Missouri; east-southeast of Kansas City, Missouri....
, Missouri, balsa wood radio-controlled aircraft are one of the primary bird harassment methods used to keep the airfield clear of raptors and other large birds, and they have also proved effective at dispersing the base’s redwing blackbird roost.
Fireworks
Fireworks can also be used as bird scarers, and some jurisdictions issue special licenses for agricultural fireworks.http://licenseinfo.oregon.gov/index.cfm?fuseaction=license_seng&link_item_id=14293 This practice has been criticized as a loophole for the sale for consumer fireworks.http://www.theledger.com/apps/pbcs.dll/article?AID=/20070430/NEWS/704300340/1036Combination Scarers
These combine multiple deterrents, such as using a pop up scarecrow combined with a gas gun, which in turn activates the distress call of a bird. These combination scarers are often managed by computers and synchronised across an area via the use of radio links.External links
- NFU online Code of Practice for using bird scarers.