Goose attacks on humans have caused serious physical injury, such as broken bones, head injuries, and emotional distress, many occurring when the person tried to avoid an attack and tripped. When fed by people, geese lose their natural fear which often leads to more violent attacks during the spring nesting season, because they will begin nesting closer to areas that people frequent.
The breeding instinct is among the strongest drives of animal behaviour. Geese usually start choosing mates and selecting a territory for nesting in late February to early March. The females lay eggs March to mid-May, and incubation begins as soon as all eggs are laid. The gander has the job, during the nesting season, of defending the female, the nesting territory and the eggs. If any intruder enters the territory, the gander will usually give a warning call before chasing it away. Some geese can be very aggressive and will only stop their attack when the intruder has left or the goose’s life is threatened.