In 1850s, a Brooklyn scientist imported 16 English sparrows to eat urban caterpillars; by 1915, the invasive birds had spread across America

House sparrows were introduced to America in 1850, which quickly led to their widespread establishment. These birds, initially intended to control insects, primarily consume seeds and grains. They rapidly spread across the continent within approximately fifty years after their introduction. Today, house sparrows compete with native birds for nesting sites and food resources. This historical introduction serves as a lesson about unintended ecological consequences.