A starling is a small to medium-sized passerine bird belonging to the family Sturnidae. The most familiar species in many regions is the common starling (Sturnus vulgaris), a stocky, iridescent black bird with a short tail, triangular wings, and a long, pointed bill. Starlings are highly gregarious, form large flocks, and are renowned for their complex vocalizations and impressive murmurations—synchronised swirling flocks that can create moving, cloud-like shapes in the sky. They are omnivorous, feeding on insects, fruits, and seeds, and many species nest in cavities, often taking advantage of holes in trees or buildings. In many parts of the world, starlings have been introduced or expanded their range and can be considered invasive due to competition with native birds and impact on crops. They mimic sounds from their surroundings and can recognize individual birds by their calls.