Australian scientists put GPS trackers on five magpies; two were removed within hours, and all five were gone within days

Imagine a team of scientists that spends months earning the trust of a flock of wild birds, tags five with tiny GPS trackers, and then expects months of useful data. Instead, within hours, the birds are already working together to peel the devices off. This incident happened in Queensland, Australia, in August 2019, and it is mentioned in a research paper titled ‘Australian Magpies Gymnorhina tibicen cooperate to remove tracking devices’, published in Australian Field Ornithology in 2022, by Crampton, Frère & Potvin.

What the researchers were really trying to do

The researchers from the University of the Sunshine Coast and the University of Queensland wanted to test a new GPS harness on the Australian magpies, which are large native birds weighing around 300 grams. GPS tracking allows scientists to learn more about the behavior and movement of animals; however, birds are usually too small to wear such trackers safely. The researchers chose magpies for the experiment because they are large and social.


Researchers spent four weeks at a site called Pacific Paradise getting a group of about ten magpies used to them, then a further six weeks getting the birds used to a feeding trap. It was the morning when they caught five magpies: one adult male, two adult females and two juveniles. Each bird received a small GPS logger attached to a lightweight harness, weighing about 2.7 grams total, roughly 0.9 percent of an adult magpie's body weight, well below the 3 to 5 percent limit researchers typically consider safe. The special feature of the harness was that it contained a single deliberately weak point, designed to break safely when a bird approached the magnet in the feeding trap, letting researchers retrieve the tracker on their own terms. In practice, that same weak point also turned out to be vulnerable to determined pecking, which is exactly where the magpies focused their efforts.

The birds did not wait for the magnet

The plan did not survive first contact with the magpies. In less than an hour after the tag had been placed on one juvenile, another magpie without a tracker began to peck at the harness. This didn’t succeed. Then an adult female magpie came along, working for about ten minutes, snapped the harness at its single weak point and freed the juvenile, all within an hour of the tracker being fitted.

At the same time, a second pair of magpies was pulling a second tracker off the top of a power line. The tagged bird and the helper working on its harness both flew down from the line to a nearby tree, where the helper continued working the harness free, an incident the researchers filmed.

The researchers witnessed four of the five removals firsthand. Day one and two trackers disappeared in hours. By day four, a third bird had lost its tracker already. On day eight, researchers found a fourth bird, a large male with a leg band, who had also shed his device. The fifth removal was not directly observed, but by then none of the five birds was carrying a tracker.

Why this is more important than it sounds

You can easily read it as a cute animal story, but it’s more than that. The paper says this may be one of the first documented cases of magpies removing tracking devices from one another, including help from birds with no tracker of their own. The helpers were not releasing themselves. They were helping another bird without any obvious benefit to themselves.

The researchers describe this as prosocial cooperation, a behavior magpies are known for. A separate 2019 study, ‘Larger group sizes facilitate the emergence and spread of innovations in a group-living bird,’ found that magpies in larger social groups solved new problems more quickly and relayed the solution to other group members. The Queensland tracker-removal case illustrates that point. One bird worked out how to break the harness, and others took it a step further.

Magpies aren't the only creatures that have their own interests at heart. In a 2017 study by Martijn Hammers and Lyanne Brouwer, Seychelles warblers were seen pulling sticky seeds from the feathers of flockmates that had become entangled in them. This is another rare example of rescue behavior in birds, similar to that seen in magpies.

The bigger lesson for wildlife tech

This is a cautionary example for scientists designing animal tracking devices. According to the authors of this research, such small pilot projects are essential before deploying the technology on a larger scale, especially when tracking intelligent animals. If the animal has flockmates clever enough to notice something is wrong, even a light, comfortable device can still be removed within days.

For the rest of us, it is a reminder that intelligence and care are not man’s prerogative. Magpies are sociable birds, co-operatively raising their young and, it seems, looking out for each other when times get tough. The research team probably was not excited to lose five GPS trackers, but it gained something rarer: first-hand evidence that these birds notice, cooperate and act without being taught.