ST. PAUL, Minn.–Pounded and strained by heavy traffic and weakened by missing bolts and cracking steel, the failed interstate bridge over the Mississippi River also faced a less obvious enemy: Birds, specifically pigeons.
Inspectors began documenting the build-up of pigeon dung on the span near downtown Minneapolis two decades ago.
Experts say the corrosive guano deposited all over the bridge's framework helped the steel beams rust faster.
Although investigators have yet to identify the cause of the bridge's Aug. 1 collapse, which killed at least 13 people and injured about 100, the pigeon problem is one of many factors that dogged the structure.
"There is a coating of pigeon dung on steel with nest and heavy build-up on the inside hollow box sections," inspectors wrote in a 1987-1989 report.
In 1996, screens were installed over openings in the bridge's beams to keep pigeons from nesting there, but that didn't prevent the build-up of droppings elsewhere.
Pigeon droppings contain ammonia and acids, said chemist Neal Langerman, of the American Chemical Society. If the dung isn't washed away, it dries out and turns into a concentrated salt. When water gets in and combines with the salt and ammonia, it creates small electrochemical reactions that rust the steel underneath.
"Every time you get a little bit of moisture there, you wind up having a little bit of electrochemistry occurring and you wind up with corrosion," said Langerman. "Over a long term, it might in fact cause structural weaknesses.''
Langerman emphasized that he wasn't saying absolutely that pigeon dung factored into the collapse of the bridge, but the problem is familiar to bridge inspectors everywhere.
The Colorado Department of Transportation spent so much time cleaning pigeon manure off bridges that it's researching new ways to keep the birds away from its spans.
The pigeon is a common sight in urban areas ranging from small rural hamlets to large metropolitan cities. Historically, pigeons are descendants of the rock dove and were brought into the country by early immigrants.
The largest problem that pigeons cause is the tremendous amount of feces they produce. Accumulation of the feces pose a health hazard to the general public. The fecal composition is acidic and erodes metal concrete and stonework. As shown in the above article from the Associated press, never mind the recent bridge collapse in Quebec in which pigeon feces was proven to be a contributing factor..
In many cases, pigeons present problems in and around the home. Permanent control of the pigeon is not possible because these birds have adapted to stress and the many sources of food made available to them in the urban environment. The most effective control available is the alteration of their environment.
PIGEONS
Pigeons are abundant in cities and around rural areas of North America. They conflict with humans for several reasons. Their droppings can deface buildings, kill vegetation, and are aesthetically displeasing when deposited on benches, sidewalks, and cars. Around grain elevators, pigeons consume and contaminate grain destined for human consumption. Pigeons carry pigeon ornithosis (psittacosis) encephalitis, newcastle disease, toxoplasmosis, salmonella food poisoning and other diseases including Avian Bird Flue. Histoplasmosis, a fungal disease that can infect people, can be contracted when cleaning up accumulations of dusty pigeon manure. Pigeon ectoparasites such as mites, fleas, ticks, and bugs may readily bite people. Pigeons are also considered a hazard around airports.
Problems with pigeons can be reduced or avoided with several methods. Pigeons can be excluded from buildings by placing 1/2 to 1 inch hardware cloth or plastic netting over eaves, vents, windows, doors and other openings. The angle of roosting ledges should be altered to 45o or more with sheet metal or wood. Porcupine wires (Nixalite or Cat Claw) can be placed on ledges and ridges of buildings to prevent roosting. Two or more strands of steel wire can be stretched above and in front of ledges to deter landings. Various sticky substances such as Roost-No-More and Bird Tanglefoot can be placed on ledges to temporarily discourage pigeons.
Noisemaking devices including ultrasonic sound, revolving lights and rubber snakes usually have little permanent effect for frightening pigeons from roosting areas. Olfactory repellents are ineffective in outdoor areas.
Avitrol, a chemical frightening agent, is available as a whole corn bait for pigeon control. It is a Restricted Use Pesticide. Birds that consume sufficient amounts of the treated bait will die but they first display distress symptoms which frighten other members of the flock away. In urban areas, this chemical should be used cautiously because high mortality can cause adverse public reactions.
Ornitrol, a chemosterilant that inhibits embryo formation without harming adults, is no longer registered for pigeon control.
Pigeon numbers also can be reduced by capturing with live traps or by shooting where permitted.
Rid-a-Bird perches containing the contact poison fenthion, are no longer registered for pigeon control.
Removing nests and destroying young also helps to depress pigeon populations but inaccessibility of nests makes the cost/benefit ratio unattractive. Respirators should be worn when removing dry pigeon manure to avoid contracting histoplasmosis.
Pigeon.petnet gets rid of pigeons quickly and safely - a goal that many business owners and homeowners have, but the reality is when property owners try to get rid of pigeons they find it very difficult to do it in a humane, effective way.
So just how do you get rid of pigeons with Pigeon.petnet ? Pigeon.petnet makes it impossible for pigeons to perch wherever you place the net, over there favorite roost, your building balconies. When you install Pigeon.petnet and combine bird defense spikes on small ledges (available at most hardware stores) your property will no longer be damaged from pigeon waste and the remnants of nesting pigeons.
People look to remove pigeons not only because they can create unsightly messes, but because they can cause significant property damage and pose a significant health hazard and can possibly carry bird flue. Condo owners will appreciate a clean and quite balcony that goes with the discrete netting.
Every building owner or property management professional who has tried to have thier pigeon problem removed will tell you that they want to accomplish that in a humane way. Environmental groups, animal rights groups and countless other people, would object to pigeons being killed or hurt in an effort to remove pigeons from your property.
Some companies that claim to assist you in getting rid of pigeons offer either temporary relief from pigeons or in their process to get rid of pigeons they cause harm to the pigeons and/or your property. Pigeon.petnet is patent pending and is totaly safe to the birds, built environment and the natural environment. All materials used in the construction of pigeon.petnet are recyclable. There is no permanent, mounting, drilling, or fastening to your building.
PIGEONPETNET.COM
Property owners that have wanted to get rid of pigeons and have tried Pigeon.petnet have found that a barrier netting is the most effective, safest way to get rid of pigeons. Using Pigeon.petnet to get rid of pigeons is also the easiest way - especially with Pigeon.petnet instructions that shows step by step how to install the Pigeon.petnet or have it installed for you.(available in Ottawa, only)
Pigeon.petnet is a great way to remove pigeons from your balcony – the net blends in to any building and will get rid of pigeons from the moment you install. Anyone who has tried to get rid of pigeons knows that it is sometimes difficult, however, Pigeon.petnet makes it impossible for the pigeons to perch on your property, effectively driving them away from your property permanently.
With Pigeon.petnet you never again have to worry about property damage from the pigeons or from drilling holes in your building to accept conventional net framing and unsightly pigeon droppings and nesting remnants Pigeon.petnet – is the most effective way to get rid of pigeons.
Why do you never see a baby pigeon? Most small birds rear and fledge their young in 2/3 weeks with young birds sometimes leaving the nest after only 10 days of life, but pigeons are different, their young remain in the nest for up to 2 months before fledging. This gives the young pigeon an advantage over many other species of bird. It leaves the nest as a relatively mature juvenile, allowing the bird to cope better in the first few days of its life, a dangerous time for all youngsters. Juveniles can be told apart from adults but it takes an experienced eye. A juvenile’s beak often appears to be far too long for the size of its body and the cere (the fleshy area at the top of the beak) is white in adults and grayish pink in juveniles.
How old are pigeons? Pigeons have lived alongside man for thousands of years with the first images of pigeons being found by archaeologists in Mesopotamia (modern Iraq) and dating back to 3000 BC. It was the Sumerians in Mesopotamia that first started to breed white doves from the wild pigeon that we see in our towns and cities today and this undoubtedly accounts for the amazing variety of colors that are found in the average flock of urban pigeons. To ancient peoples a white pigeon would have seemed miraculous and this explains why the bird was widely worshipped and considered to be sacred. Throughout human history the pigeon has adopted many roles ranging from symbols of gods and goddesses through to sacrificial victims, messengers, pets, food and even war heroes!
Biblical references The first biblical reference to the pigeon (or dove) was in the Old Testament of the Bible in the first millennium AC and was the story of Noah and the dove of peace. Later, in the New Testament, the pigeon was first mentioned during the baptism of Christ where the dove descended as the Holy Spirit, an image now used extensively in Christian art. These early biblical references have paved the way for the many different ways that the urban pigeon is viewed in modern societies worldwide. Perception of the pigeon through the centuries has changed from God to the devil and from hero to zero!
Pigeon poop – foul or fantastic? Although pigeon poo is seen as a major problem for property owners in the 21st Century, it was considered to be an invaluable resource in the 16th, 17th and 18th century in Europe. Pigeon poop was a highly prized fertiliser and considered to be far more potent than farmyard manure. So prized in fact that armed guards were stationed at the entrances to dovecotes (pigeon houses) to stop thieves stealing it! Not only this, but in England in the 16th century pigeon poop was the only known source of saltpetre, an essential ingredient of gunpowder and was considered a highly valued commodity as a result. In Iran, where eating pigeon flesh was forbidden, dovecotes were set up and used simply as a source of fertilizer for melon crops and in France and Italy it was used to fertilize vineyards and hemp crops.
The pigeon as a war hero In modern times the feral pigeon has been used to great effect during wartime. In both the first and second World Wars the pigeon saved hundreds of thousands of human lives by carrying messages across enemy lines. Pigeons were carried on ships in convoys and in the event of a U-boat attack a messenger pigeon was released with details of the location of the sinking ship. In many cases this lead to the survivors being rescued and lives saved. Mobile pigeon lofts were set up behind the trenches in the First World War from which pigeons often had to fly through enemy fire and poison gas to get their messages home. The birds played a vital role in intelligence gathering and were used extensively behind enemy lines where the survival rate was only 10%. In the Second World War pigeons were used less due to advances in telecommunications, but the birds relayed invaluable information back to the allies about the German V1 and V2 Rocket sites on the other side of the Channel.
The pigeon as a messenger The earliest large scale communication network using pigeons as messengers was established in Syria and Persia about 5th Century BC. Much later in the 12th Century AD the city of Baghdad and all the main towns and cities in Syria and Egypt were linked by messages carried by pigeons. This was the sole source of communication. In Roman times the pigeon was used to carry results of sporting events such as the Olympic Games and this is why white doves are released at the start of the Olympic Games today. In England, prior to the days of telegraphs, pigeons were often taken to soccer matches and released to carry home the result of the game. Their use as a messenger in war time resulted in many pigeons being awarded honors by both the British and French Governments. Incredibly, the last ‘pigeon post’ service was abandoned in India in 2004 with the birds being retired to live out the rest of their days in peace.
The religious significance of the pigeon Many religious groups including Muslims, Hindus and Sikhs feed pigeons for religious reasons. Many older Sikhs feed pigeons ceremoniously to honour the high priest and warrior Guru Govind Singh who was a known friend of the pigeon (or rock dove). Some Sikhs also feed pigeons because they believe that when they are reincarnated they will never go hungry if they have fed pigeons in their previous life. Other religious groups in India believe that when a person dies his or her soul assumes the form of a bird (normally a pigeon) and therefore by feeding birds they are caring for the souls of their departed ancestors. The pigeon is revered in India with huge flocks numbering many thousands of birds being fed daily at Hindu temples in town and city centres throughout the country. In both eastern and western societies many of the most entrenched pigeon-related problems in urban areas are considered to be caused, certainly in part, by religious feeding of the birds. In the Christian religion the pigeon is both a symbol of peace and of the Holy Spirit.
Famous pigeons During the First World War a pigeon named Cher Ami (Dear friend) saved the lives of many French soldiers by carrying a message across enemy lines in the heat of battle. Cher Ami was shot in the chest and the leg, loosing most of the leg to which the message was attached, but continued the 25 minute flight avoiding shrapnel and poison gas to get the message home. Cher Ami was awarded the French ‘Croix de Guerre’ for heroic service. Another heroic pigeon named G.I. Joe saved the lives of a thousand soldiers in World War 2 after British troops had established a position within an Italian town that was due to be bombed by allied planes. Communication equipment was down and the only means of stopping the raid was to attach a hastily written message to G.I. Joe and send him to the HQ. G.I. Joe flew 20 miles in 20 minutes arriving at the air base whilst the planes were taxiing on the runway. Disaster was averted with 5 minutes to spare. G.I. Joe received the ‘Dickin’ medal for his bravery.
‘Rock Dove’ or ‘pigeon’? The feral pigeon that we see in our towns and cities today is descended from the Rock Dove (Columba livia), a cliff dwelling bird historically found in coastal regions. The word ‘pigeon’ is actually derived from the Latin word ‘pipio’ which meant ‘young bird’. The word then passed into Old French as ‘pijon’ and thus the English name ‘pigeon’ was derived and is now used the world over as a common name for the Rock Dove. Other common names include ‘domestic pigeon’ and the ‘feral pigeon’. In 2004 British and American Ornithologists officially re-named the bird the Rock Pigeon.
Why do pigeons bob their heads? The pigeon has side mounted eyes unlike humans and owls which have forward facing eyes. As a pigeons have monocular vision rather than binocular vision they bob their heads for depth of perception. The pigeon’s eyes work much better with stationary images and therefore, as the pigeon takes a step forward the head is temporarily left behind. The next step jerks the head forward again and so on. This allows the bird to correctly orient itself.
Pigeon-gram Air Mail service The first organised pigeon air-mail service was started in 1896 between New Zealand and the Great Barrier Reef. The sinking of the SS Wairarapa off the Great Barrier Reef, with the loss of 134 lives, was a catalyst for the service. News of the disaster did not reach New Zealand for 3-days and as a direct result a pigeon-gram service was set up between the two islands. The first message was carried in January 1896 and took less than 1.75 hours to reach Aukland. Up to 5 messages were carried by each pigeon with the record time for the journey being held by a pigeon called ‘Velocity’ taking only 50 minutes and averaging 125 kmph (only 40% slower than a modern aircraft!). Special pigeon-gram stamps were issued costing 2/- each (20 cents) with the fee being paid in cash before the pigeon was released.
Pigeons in Wall Street One of the richest and most famous families in the world amassed its wealth, certainly in part, as a result of exploiting the pigeon. In the early 1800’s the Rothschild family set up a network of pigeon lofts throughout Europe and used homing pigeons to carry information between its financial houses. This method proved to be quicker and more efficient than any other means of communication available at the time. The speed of the service combined with the ability to send and receive information ahead of the competition helped the Rothschild family amass a fortune which still exists today.
Mating habits of the pigeon The feral pigeon mates for life and can breed up to 8 times a year in optimum conditions, bringing two young into the world each time. The frequency of breeding is dictated by the abundance of food. The eggs take 18/19 days to hatch with both parents incubating the eggs. Young dependant pigeons are commonly known as ‘squabs’. Both parents feed the young with a special ‘pigeon milk’ that is regurgitated and fed to the squabs. Each squab can double its birth weight in one day but it takes 4 days for the eyes to open. When squabs are hungry they ‘squeak’ whilst flapping their wings and as a result they are also commonly known as ‘squeakers’. At approximately 2 months of age the young are ready to fledge and leave the nest. This much longer than average time spent in the nest ensures that life expectancy of a juvenile pigeon is far greater than that of other fledglings.
Pigeons are big business We normally think of the pigeon as being an unwelcome guest in our towns and cities but most of us are unaware that racing pigeons can be worth huge sums of money. One racing pigeon recently sold for a staggering $132,517.00! The 3-year old bird was a champion racer beating 21,000 other pigeons in one long distance race. For this reason he was bought by one British company that breeds racing pigeons for ‘stud’. One very happy pigeon! The previous record price for a pigeon was $73, 800.00.
How do pigeons navigate? There are many theories about how pigeons manage to return ‘home’ when released 100’s of miles from their loft. A champion racing pigeon can be released 400-600 miles away from its home and still return within the day. This amazing feat does not just apply to ‘racing’ or ‘homing’ pigeons, all pigeons have the ability to return to their roost. A 10-year study carried out by Oxford University concluded that pigeons use roads and freeways to navigate, in some cases even changing direction at freeway junctions. Other theories include navigation by use of the earth’s magnetic field, visual clues such as landmarks, the sun and even infrasounds (low frequency seismic waves). Whatever the truth, this unique ability makes the pigeon a very special bird.
Famous people and pigeons The humble pigeon has attracted some very famous fans over the last few thousand years ranging from Royalty to rock and roll singers and actors through to fashion designers. One of the most famous royals is Queen Elizabeth of England who has lofts and pigeon keepers at her estate in Sandringham, Norfolk. Elvis Presley had a soft spot for pigeons and Mike Tyson is also an enthusiastic pigeon keeper. Even Maurizzo Gucci the internationally renowned fashion designer is a keen pigeon fancier spending a reputed $10,000 on one American pigeon. 'One famous couple, Paul Newman and Joanne Woodward, are keen pigeon fanciers but after being swamped by autograph hunters at a pigeon show they are apparently less comfortable to show their affection for the birds publicly.' Last but not least, and probably the most famous of all... Noah!
Pigeon disasters Probably the greatest disaster to befall the species was the extermination of the passenger pigeon in North America in the early part of the 20th century. It is estimated that there were 3-5 billion passenger pigeons in North America at the time. Flocks of 100,000’s of the birds would blacken the skies as they flew over but early settlers managed to wipe out every last bird by 1914 through over-hunting. A more recent, and quite bizarre disaster, befell tens of thousands of racing pigeons released from Nantes in France as part of a race held to celebrate the centenary of the Royal Racing Pigeon Association in England. 60,000 pigeons were released but only a few birds ever arrived back at their lofts throughout southern England. One theory suggests that the sonic boom created by Concorde as it flew over the English Channel, at the precise time the pigeons would have been at the same point, completely disorientated the birds, compromising their inbuilt navigation system.
Pigeons as lifesavers Although pigeons are one of the most intelligent of all the bird species man has found limited uses for the birds other than for the purposes of sport, food and as a message carrier. A team of navy researchers, however, has found that pigeons can be trained to save human lives at sea with high success rates. Project Sea Hunt has trained a number of pigeons to identify red or yellow life jackets when floating in the water. The pigeons were not only found to be more reliable than humans but they were also many times quicker than humans when it came to spotting survivors from a capsized or sinking boat. The pigeon can see color in the same way that humans do but they can also see ultra-violet, a part of the spectrum that humans cannot see, and this is one of the reasons they are so well adapted to lifesaving.
Pigeons in the news One of the world’s most famous news agencies, Reuters, started its European business by using trained homing pigeons. The service was started in 1850 with 45 pigeons carrying the latest news and stock prices from Aachen in Germany to Brussels in Belgium. Although a telegraph service between the two countries existed, numerous gaps in the transmission lines made communication difficult and slow. The birds travelled the 76 miles in a record-breaking two hours beating the railway by four hours.
Why do you never see a baby pigeon? Most small birds rear and fledge their young in 2/3 weeks with young birds sometimes leaving the nest after only 10 days of life, but pigeons are different, their young remain in the nest for up to 2 months before fledging. This gives the young pigeon an advantage over many other species of bird. It leaves the nest as a relatively mature juvenile, allowing the bird to cope better in the first few days of its life, a dangerous time for all youngsters. Juveniles can be told apart from adults but it takes an experienced eye. A juvenile’s beak often appears to be far too long for the size of its body and the cere (the fleshy area at the top of the beak) is white in adults and greyish pink in juveniles.
What is the natural predator of the pigeon? Although the natural enemy of the feral pigeon is now man, with millions of pigeons being killed in control operations the world over, it is the peregrine falcon that is the pigeons’ real natural predator. Although a shy and retiring bird that has its natural habitat along rocky coastlines, the peregrine is now being introduced into towns and cities as a ‘natural’ pigeon control. The peregrine is the fastest bird on the planet when in a dive and can achieve speeds in excess of 200 mph, over 130 mph faster than a pigeon.
Are pigeons intelligent? Pigeons are considered to be one of the most intelligent birds on the planet with pigeons being able to undertake tasks previously thought to be the sole preserve of humans and primates. The pigeon has also been found to pass the ‘mirror test’ (being able to recognise its reflection in a mirror) and is one of only 6 species, and the only non-mammal, that has this ability. The pigeon can also recognise all 26 letters of the English language as well as being able to conceptualise. In scientific tests pigeons have been found to be able to differentiate between photographs and even differentiate between two different human beings in a photograph when rewarded with food for doing so.