call, attack call, snarl call and copulation call. The alarm call is a harsh scream, and while foraging together common starlings squabble incessantly. They chatter while roosting and bathing, making a great deal of noise that can cause irritation to people living nearby. When a flock of common starlings is flying together, the synchronised movements of the birds' wings make a distinctive whooshing sound that can be heard hundreds of metres away. Behaviour and ecology The common starling is a highly gregarious species, especially in autumn and winter. Although flock size is highly variable, huge, noisy flocks - murmurations - may form near roosts. These dense concentrations of birds are thought to be a defence against attacks by birds of prey such as peregrine falcons or Eurasian sparrowhawks. Flocks form a tight sphere-like formation in flight, frequently expanding and contracting and changing shape, seemingly without any sort of leader. Each common starling changes its course and speed as a result of the movement of its closest neighbours. Very large roosts, up to 1.5 million birds, form in city centres, woodlands and reedbeds, causing problems with their droppings. These may accumulate up to deep, killing trees by their concentration of chemicals. In smaller amounts, the droppings act as a fertiliser, and therefore woodland managers may try to move roosts from one area of a wood to another to benefit from the soil enhancement and avoid large toxic deposits. Flocks of more than a million common starlings may be observed just before sunset in spring in southwestern Jutland, Denmark, over the seaward marshlands of Tønder and Esbjerg municipalities between Tønder and Ribe. They gather in March until northern Scandinavian birds leave for their breeding ranges by mid-April. Their swarm behaviour creates complex shapes silhouetted against the sky, a phenomenon known locally as sort sol ("black sun"). Flocks of anything from five to fifty thousand common starlings form in areas of the UK just before sundown during mid-winter. These flocks are commonly called murmurations. Feeding The common starling is largely insectivorous and feeds on both pest and other arthropods. The food range includes spiders, crane flies, moths, mayflies, dragonflies, damsel flies, grasshoppers, earwigs, lacewings, caddisflies, flies, beetles, sawflies, bees, wasps and ants. Prey are consumed in both adult and larvae stages of development, and common starlings will also feed on earthworms, snails, small amphibians and lizards. While the consumption of invertebrates is necessary