The European Starling (Sturnus vulgaris) is a common, non-native bird in North America, introduced in the late 19th century. With populations in the hundreds of millions, this adaptable species has spread across the United States and Canada, thriving in urban, suburban, and agricultural areas. Their widespread presence and rapid reproduction classify them as an invasive species, leading to significant negative consequences.
Agricultural Damage
European Starlings inflict substantial economic damage on the agricultural sector through their feeding habits. These birds consume and contaminate a variety of crops, including grains like corn and wheat, and fruits such as cherries, grapes, blueberries, strawberries, peaches, figs, and apples. Large flocks can quickly devastate fields and orchards, leading to significant financial losses for farmers. For instance, in 2012, bird damage to sweet cherries ranged from 3% to 25%, and to grapes from 4% to 10%, with starlings being primary culprits.
Beyond direct consumption, starlings also peck and slash at fruits, reducing their quality and making them more susceptible to diseases and pests. In livestock operations, starlings consume feed, particularly high-protein supplements, and contaminate remaining feed and water with their droppings.
A flock of 1,000 birds can consume approximately 100 pounds of grain daily. In winter, flocks of up to 2,000 birds can consume 1 to 2 tonnes of feed in a month, spoiling an additional 500 to 1,000 kg. Annual agricultural damage caused by starlings in the U.S. can reach hundreds of millions of dollars.
Ecological Disruption
European Starlings disrupt native ecosystems and bird populations due to their aggressive and competitive nature. They are known for their competition with native cavity-nesting birds for limited nesting sites. Species such as Eastern Bluebirds, Purple Martins, woodpeckers, and flickers are frequently outcompeted or displaced by starlings.
Starlings often take over existing nests, evicting native birds, destroying their eggs, or even killing nestlings. This aggressive behavior prevents native species from breeding successfully where starlings are abundant. They also outcompete native species for food resources, leading to declines in local bird populations and altering natural food webs. Their ability to rapidly colonize new areas intensifies pressure on native avian communities.
Public Health and Nuisance
Starlings present various issues to human environments, impacting public health and causing nuisance. Large starling roosts in urban and suburban areas generate noise pollution. These aggregations also lead to the accumulation of corrosive droppings on buildings, vehicles, and public spaces. The uric acid in starling droppings can corrode metal, masonry, stone, and paint, resulting in property damage and unsanitary conditions.
Beyond property damage, starling droppings pose health risks, transmitting bacterial, fungal, and viral pathogens to humans and livestock. Diseases like histoplasmosis (a respiratory illness from fungal spores), salmonellosis, and E. coli are linked to their droppings. Starlings in livestock facilities can contaminate feed and water, spreading diseases among animals and potentially humans. Their nests, often in building cavities like vents and chimneys, can clog systems, creating fire hazards and disrupting airflow.