Emeritus Professor Gisela Kaplan suggests that cyclists dismount if they know they are near a magpie nesting site to avoid being swooped. Photo: Screenshot / Facebook / Transport and Main Roads Queenland
The start of spring coincides with magpie swooping season.
Up and down New Zealand cyclists, golfers, farmers and pedestrians just minding their own business are all fair game once they step inside the bird's territory.
The Waipiata Country Hotel in Central Otago even has Magpie Alley Talley Board tallying how many cyclists have been swooped while cycling on the nearby Otago Rail Trail.
Emeritus Professor Gisela Kaplan from the University of New England is an expert in animal behaviour, and also literally wrote the book on Australian magpies.
She said magpies were amongst the most intelligent songbirds in the southern hemisphere.
"There is one exception to this rule, when they cross a road and the road is in their territory they ask for respect for them to go first and of course most motorists don't know that rule, that in the territory that belongs to them they should have first run of the road, [the motorists] don't know that and then the magpie gets killed."
Magpies were very etiquette driven and had very firm rules, she said.
"That works very well for them and when you play by the rules they are extremely friendly."
Magpies will support each other and are very useful birds, she said.
"They're useful for farmers for all the pests they remove, they are useful for other birds because they tend to protect them against predators."
People's experience of being dive bombed by magpies was mobbing behaviour that related to spring and nesting time, she said.
"When the female sits on the eggs, she has to stay there for four weeks except for very small breaks when she may get up and turn the eggs around or stretch her legs or whatever, but she can't actually leave.
"So the male has the job to make sure that these four weeks while she's brooding she's safe from any attack or mishap and the nest is safe."
Most male magpies were very good at guarding their mate's nest, but if they were not then the female bird would dismiss them and make them leave, she said.
"But it's only the male and only for four weeks and for one reason only and that's called nest effects but nothing else, not for the rest of the year they wouldn't attack."
Magpie attacks were not related to the birds being aggressive, but rather to them protecting their nests, she said.
"Some people are terrified by it, but the intention is not to hit you, the intention is to make sure you understand that there is a nest nearby and you haven't slowed down or indicated that you're not hostile - so if you're not hostile and you're a nice person you won't ever get swooped, ever."
Many other types of male song birds would do the same to protect nests, but it was not as noticeable because the birds tended to be far smaller, she said.
Magpies are amongst the most intelligent songbirds in the southern hemisphere, Gisela Kaplan says. Photo: CC BY-SA 4.0 via Wikimedia Commons
Magpies assume that if someone is moving at a fast speed, for example either running or on a bike, that they are a threat, she said.
The best way to prevent being attacked was if councils indicated where there were magpie nests and for cyclists to then get off their bike, she said.
Magpies are also able to recognise people's faces and they don't dive bomb people they are familiar with, she said.
"So say you're walking your dog in a park every morning and you don't even need to wear the same clothes but you have the same gait and when a magpie is up above or there's a sign there's a magpie nest near, you look up where they are and they see your face, they you walk on, you may even say 'hello magpie', you walk on and next day you come, you won't be swooped."
A male magpie uses facial recognition and is very good at risk assessment and unless they detect a risk they will not bother to swoop, she said.
Once magpies choose a property to live on they can be there for some time, she said.
"I've had one family stay on our property for 18 years and it suddenly disappeared, presumed dead from an accident or something because he was a very good father and they produced viable offspring each year and when the young started fledging they brought them around the back porch."
It was quite a formal exercise, she said.
The parents would land and be followed by the offspring, she said.
"Then I've gone in and given them a little reward, but I gave the reward to the parents not to the offspring because there's a rule, you know the parents decide what the offspring eat ... you see if you give it to the young you undermine their [the parent's] authority."
