Conventional wisdom went out the window on a day in September 2016.
If only male magpies attack and they are territorial you should only get attacked by one at a time. But on the corner of Takalvan Street / Walker Street in Bundaberg two went after me. So either mama joined the fray or it was a gay couple or they are not that territorial and there were two nests near by.
I only noticed the double after I had done what they tell you to do. Get off my bike and look at the bird. Big mistake. The other one swooped me from behind and then swapped position with the first one. So I was always in the middle between them. And they were sitting on very low branches and thus very close to my eyes.
My three plastic cable ties probably prevented them from actually hitting me (while my fake eyes had no effect). But it was still an annoying encounter so I decided to upgrade my defenses.
I got a pack of 10 steel cable ties (370mm x 4.6mm) from Bunnings and deployed them around my helmet instead of the plastic ones. They shimmer and wiggle around my head, look ridiculous and very promising.
Time for a road test. I had been attacked on that spot all three times I had been there (only one bird the first two times) and I had seen another cyclist getting attacked. And my postman also told me he gets attacked there.
I rode past the spot twice, heard only one squawk but there was no magpie in sight. I came back two days later, also no attack, not even an aborted one. I also rode through some parkland with plenty of magpies but also not attack.
So it just maybe that I found a very effective and simple defense: Long wiggling steel cable ties. Try it out.