While magpies are not aggressive for most of the year, a small percentage can become highly aggressive during breeding season which runs from late August to mid-October.
People passing by magpie territory may be seen by the birds as “invaders,” prompting the birds to fly low and fast overhead.
While usually only a warning, some birds may resort to striking people on the head with their beak or claws.
City of Rockingham Mayor Barry Sammels encouraged residents to remain vigilant when outdoors over the coming weeks.
"Fortunately most magpies aren’t aggressive but at this time of year some may attack passersby," Mayor Sammels said.
"Taking steps such as avoiding nesting sites, wearing a hat or sunglasses and keeping an eye out for their distinctive calls will help protect you from a possible attack.
"If residents have concerns about particular hotspots the City will investigate and if necessary we can install temporary warning signs to alert the public of persistently aggressive birds."
For more information on protecting yourself from swooping magpies visit Flora and Fauna.