HARM & DAMAGE CAUSED BY BIRDS
Despite the fact that birds are well-wishers of mankind, we have with the changing times, encroached upon most of their territories. Result, we have suffered irreparable losses in the form of human lives, besides great economic losses caused due to the birds, but without any fault of theirs. For instance, several aircraft accidents, which occur every year throughout the world, birds are found to be responsible for many of them. According to an estimate in year 1976 damage to aircrafts involved in bird-hits was to the tune of about US$1100 million. In United States alone airlines suffer annual losses of about $2.5 to 3 crores ($25-30 million) due to birds.
During 1983-84 the Federal Aviation Administration of USA conducted a study, which showed that gulls and black kites were the species most commonly involved in the bird-related accidents. According to the British Ministry of Defense reports, gulls were involved in most bird strikes to military aircrafts. An analysis of military aircrafts also revealed that bird strikes which had taken place in several European countries during the period from 1978 to 1984 AD showed that gulls were responsible for 28.6 per cent cases, swifts, martins and swallows 14.5 per cent and pigeons 10.2 per cent incidents. The UK Civil Aviation Authority also stated that the rate of bird-strikes was 5.2 per ten thousand aircraft movements. It reported that during 1976-80 the birds damaged over 330 aircraft engines.
Indian Air Force is another major sufferer due to bird hits. In a meeting of Airport Safety and Security Committee held in December 1995 in Bareilly (UP) IAF representatives revealed that the Air Force had suffered a loss of over Rs. 900 crores, due to bird-hits in the past 10 years at its “Trishul” air base (Bareilly) alone.
As far as damage to agriculture is concerned, the red-billed quelea of Africa is the most significant bird pest in the world. In African continent food grain damage, up to the level of some $2.5 crore, ($25 million), is attributed to these birds annually. If we compare this damage with the total cereal production of the continent it is less than one per cent.
North and Central American red-winged blackbird and the European starlings are the only other world’s greatest bird pests that might rival the red-billed quelea. In United States in 1970 and 1971 blackbirds caused damage to ripening corn to the tune of $1.80 crore ($18 million) and the losses to emerging corn by common grackles and ring-necked pheasants were to the tune of $5 crores ($50 million). In 1976 Canadian agriculture losses, primarily of wheat, in fourteen provinces were to the tune of $12 crores ($120 m) caused by seed-eating birds and waterfowls.
There are numerous species that are responsible for agricultural losses in one form or the other. For example, in 1960s in Germany, starlings, which are very fond of soft fruits, inflicted annual loss of $30 lakh ($3 million) to grapes and cherries. Not only that the huge roosts of these birds cause breaking of branches by their sheer weight and the chemical action of their accumulated droppings either kill the tree or inhibit growth. In one of the British forests of pine and spruce, covering about eight thousand hectares of area, all trees died due to starling droppings. In some of the roosts 15 inches thick dropping-layer have been found. They also cause damage to buildings.
Bird droppings are very acidic in nature. They actually eat away at many substrates, especially tar-based roofing materials. Droppings which are allowed to accumulate on roofs will eat into the material and eventually cause leaks. The life expectancy of a warehouse roof can be cut in half by just a light, but continuous, application of bird droppings.
Pigeon, starling and sparrow nests are often built in rain gutters, drains and corners of roofs where drains are located. Several warehouses every year experience great damage, even collapsed roofs, when drainage systems are blocked and standing water is allowed to rise just six inches. A collapsed roof that resulted in death or great physical damage could put a company out of business.
Acidic bird droppings can do great damage to air conditioning equipment, industrial machinery, siding, insulation etc. Not only is the equipment being damaged, but workers are exposed to a dangerous health-risk any time they work on or around the machinery.
Nesting materials are usually very flammable due to their construction of straw, twigs and dried droppings. When birds build their nests inside electric signs or other machinery there is a great risk of fire. Electric sign companies blame bird nests for most of their sign fires.
Bird nests built in chimneys and ventilation systems can not only spread diseases through the system, but can actually block air-flow which can have horrible consequences. A family of five in Cleveland was killed by carbon monoxide poisoning just before Christmas 1995 because the exhaust system of their fireplace was blocked by bird nests.
Most bird droppings, but especially pigeon and gull, will fade paint finishes by actually eating into the protective coating and the paint itself. The longer the droppings are allowed to sit on the paint, the more damage it will do.
Birds flying around the insides of warehouses, airplane hangars, factories and convention centres can wreak havoc. Bird droppings can ruin plastics when they are being moulded, they can destroy any number of different chemicals and liquids which are being manufactured, they will ruin new and old paint jobs on aircraft, and they can contaminate food which is being made or packaged. These types of ruined products often cost millions of dollars in waste.
Droppings and nesting materials on or around a building send a message to the public that this building is not properly maintained. One is forced to wonder how clean a restaurant’s kitchen could be if they don’t even care about bird droppings dripping down the sign.
Pigeons have been known to enter attics of houses, apartments, restaurants and other buildings through openings that have been either broken or never sealed off in the first place. In most cases the pigeons set up homes in these protected areas, build nests and discard their bodily waste. Often the weight of the droppings becomes so great that the actual ceiling collapses. One would guess that this type of occurrence would be extremely random but it happens with alarming frequency.
Disease caused by birds
Birds are also carrier of deadly diseases. Bird flu or avian influenza is the popular name of the ailment caused by the H5N1 virus, which spreads through contact with infected birds or contaminated surfaces, however, risk of infection in humans is low and person-to-person transmission is rare. It is one of hundreds of types of viruses that are carried by birds. These illness causing agents (viruses) when mutate and create new strains become deadly even for humans. One group of viruses rapidly kills domestic chickens and some species of wild birds and the H5N1 is in this group. First detected in humans in 1997 this strain of virus is highly contagious among wild birds and often fatal to domestic birds and poultry. In Southeast Asia 60 people have died due to this virus between 2003 and 2005. This flu was first detected in southern China in 1996. It caused a large outbreak in Hong Kong in 1997 killing six people. Scientists say genetic mutation in the virus has allowed easier infection of mammals. According to the findings, so far nearly all human victims of the deadly virus had direct contact with birds, and no strain of H5N1 has passed easily from one human to another. Domestic cats in Germany and Austria have contracted the virus, probably be eating wild birds.
When the diseased bird directly defecates into human food or water source it poses great danger to human health. In the summer of 1993, New York faced a health crisis when several hundred people came down with a mysterious ailment. The illness was traced to sea gull droppings in an old city reservoir. Besides direct contamination, airborne spores from drying faeces in air ducts and vents can settle on exposed food and transfer disease. Several thousand cases of food poisoning (Salmonella) every year are attributed to this disease transmission route.
As bird faeces and/or the contaminated soil it rests on, dries or is disturbed, microscopic pieces break off and become airborne. These airborne particles can contain dormant fungi and/or bacteria. When breathed into the lungs, the warm, moist environment of the lung lining provides a breeding ground for the infectious agents. Common symptoms of this type of infection are flu like in nature: coughing, elevated temperature, restricted breathing and general body fatigue, and last roughly two to four days. Majority of the time, body’s defences will contain the invaders even before minor symptoms appear but in a small percentage of cases, major infection causing long term disability and even death occurs. It is worth noting that there is no known medical cure for internal fungal infections. After the Northridge earthquake, several thousand people came down with flu like respiratory symptoms. The ailment was called Valley Fever and was caused by people breathing in dust and airborne debris filled with histoplasmosis spores and related fungal agents stirred up by the earthquake.
Infection occurs when a worker or resident gets faecal dust or droppings in an open wound or cut. This commonly occurs when handling old rusty, sharp porcupine wire ledge products which are covered with bird faeces. The wound site becomes red, puffy and puss-filled. Antibiotics are often needed to cure the infection. In some rare cases, infection of the blood (Septis) or internal infection can also occur causing serious illness or death. Proper attire and care must always be used when cleaning a bird site or installing bird control products. If a cut or injury occurs, thoroughly wash and disinfect the wound and cover with a sterile bandage to minimize risk of infection.
Pest birds harbor ticks, fleas, mites and other ectoparasites, which transfer diseases. Over forty types of parasites live either on the birds, in their nests or in the places they roost. They are responsible for transmission of several hundred viral and bacterial agents. These diseases include plague, encephalitis, pox and meningitis.