Birds are usually harmless, beneficial animals, but sometimes due to their habits, they become pests. Whenever bird behaviour adversely affects human activities they can be classed as pests. These type of situations include destroying fruit orchards and crops, damaging & fouling commercial buildings, nesting in roofs and gutters, damaging golf courses, parks and other recreational facilities, contaminating food and water, affecting aircraft at airports and aerodromes and threatening survival native birds and wildlife.
Here we look at some of the main situations where birds are in conflict with humans and their activities.
Destroying fruit and crops
Birds have long been a significant economic threat to the agricultural industry. It is estimated that birds cause nearly $300 million worth of damage to horticultural crops in Australia annually. This includes damaging grapes in vineyards, fruit trees in orchards, cereal crops, grain in storage, etc.
Nesting in buildings
Birds commonly roost or nest in sheds, buildings and roof spaces, often gaining access through broken tiles, damaged roof capping and through guttering. This often occurs during nesting season and the biggest offenders are usually pigeons, starlings and indian mynas. Some birds nest in guttering and down pipes which can cause blockages resulting in water overflowing, moisture damage and pooling of stagnant water.
Bird droppings are highly corrosive and can cause significant damage to paintwork and other surfaces on buildings. Added to this bird droppings are extremely unsightly and deface building exteriors, car parks, railway stations, shopping centres, etc. Bird droppings can also contaminate food in storage such as wheat and grain, and food production facilities. Pigeons are the biggest offenders here.
Carriers of parasites
Birds are hosts to parasites such as bird mites and bird lice. These have the potential to be come pests of humans when nests in roofs and gutters become abandoned and the mite or lice seek out a new host (humans). This is commonly a problem in domestic homes.
Bird pests at airfields and airports
Birds frequently become pests at airfields and airports largely due to the open grassed areas. They can be a real problem for propeller driven aircraft but a major hazard for jet engines as they can be sucked into the engines during take off and landing.
Spread of bacteria and disease
Birds and their droppings can carry over 60 different diseases. Some of the nastier diseases found in dried bird droppings include:
Histoplasmosis - a respiratory disease which can be fatal. Caused by fungus growing in dried bird droppings
Cryptococcosis - a disease which begins as a pulmonary disease but may later affect the central nervous system. Caused by yeast found in the intestinal tract of pigeons and starlings.
Candidaisis - a disease which affects the skin, mouth, respiratory system, intestines and vagina. Again cause by yeast or fungus spread by pigeons.
Salmonella - a bacteria found in bird droppings that causes food poisoning. Again linked to pigeons, starlings and sparrows.
Impact on native bird species
Indian mynas are the biggest offenders here. Indian myna birds are among the worlds top 100 most invasive species. They are aggressive and compete with native animals for space. Indian myna birds force other birds and small mammals out of their own nests and tree hollows, and even throw other bird’s eggs and chicks out of their nests.