Angry birds dive-bomb police officers

Magpies are ubiquitous in urban areas all over Australia, and have become accustomed to people. A small percentage of birds become highly aggressive during breeding season from late August to early October, and will swoop and sometimes attack passersby. The percentage has been difficult to estimate but is significantly less than 9%. Almost all attacking birds (around 99%) are male, and they are generally known to attack pedestrians at around 50 m (150 ft) from their nest, and cyclists at around 100 m (300 ft). Attacks begin as the eggs hatch, increase in frequency and severity as the chicks grow, and tail off as the chicks leave the nest.

These magpies may engage in an escalating series of behaviours to drive off intruders. Least threatening are alarm calls and distant swoops, where birds fly within several metres from behind and perch nearby. Next in intensity are close swoops, where a magpie will swoop in from behind or the side and audibly "snap" their beaks or even peck or bite at the face, neck, ears or eyes. More rarely, a bird may dive-bomb and strike the intruder's (usually a cyclist's) head with its chest. A magpie may rarely attack by landing on the ground in front of a person and lurching up and landing on the victim's chest and peck at the face and eyes.

Magpie attacks can cause injuries, typically wounds to the head and particularly the eyes, with potential detached retinas and bacterial infections from a beak used to fossick in the ground. A 13-year-old boy died from tetanus, apparently from a magpie injury, in northern New South Wales in 1946. Being unexpectedly swooped while cycling is not uncommon, and can result in loss of control of the bicycle, which may cause injury. In Ipswich, a 12 year old boy was killed in traffic while trying to evade a swooping magpie on 16 August 2010