Geese chased out of a park in Chicago returned to the area twice as quickly on days when they were harassed, compared with days when they left of their own accord.
Canada geese can be a nuisance – but harassing them to leave an area may backfire.
These birds, which often take up residence in densely-populated areas in North America and northern Europe, sometimes attack people during nesting season, leave droppings all over playground equipment or, most seriously, pose a risk to air traffic at airports. Read more in New Scientist.