Researchers in Queensland fitted five Australian magpies with tiny GPS trackers, hoping to map their movements and social relationships. The flock had other plans.
Within about ten minutes, an untagged adult female was using her bill to work at the harness on a juvenile. The tracker came off. Nearby, another magpie was helping a second tagged bird on a powerline. Devices that had been designed to stay attached for weeks disappeared within minutes to days.
I like this story partly because it resists the tidy distinction between a successful experiment and a failed one. The researchers lost the movement data they went looking for, but the birds produced an observation nobody had planned.
The trackers were meant to release safely
Joel Crampton, Celine Frère and Dominique Potvin described the pilot in a 2022 paper in Australian Field Ornithology. They worked with a social group of magpies at Pacific Paradise on Queensland’s Sunshine Coast.
The team spent weeks habituating the birds to a feeding station before catching five in one morning: one adult male, two adult females and two juveniles. Each bird received a GPS logger and harness weighing about 2.7 grams in total, plus identification bands.
The harness included a deliberate weak point. When a tagged bird returned to the feeding station, a magnet was supposed to trigger the release so the tracker could be recovered without another capture. Before deployment, the design had survived strength tests. A magpie trying to remove it without the magnet would need to find the one vulnerable section and apply a sharp, targeted force.
That safety feature appears to have become the birds’ exit.
The first removal took less than an hour
The researchers saw tagged birds peck at their own harnesses, but the clearest removals involved help from untagged flockmates.
One juvenile first tried to reach its own tracker. Another juvenile approached and pecked at the harness without releasing it. An adult female then worked at several points until the device came away, about ten minutes after she began and within an hour of the tracker being fitted.
At the same time, a different adult was attending to another tagged magpie on a powerline. The pair fell during the attempt, moved to a nearby tree and continued. By the next day, researchers saw only two birds still wearing trackers. On later visits, identifiable banded birds returned without them, and no tracker remained on any observed magpie.
The team directly observed four magpies participating in removal attempts. They did not witness every final release, recover every device or establish whether one particularly skilled bird did most of the work. This was a descriptive pilot involving five tagged animals, not a controlled test of how often magpies cooperate.
Cooperation is clear; altruism is harder to establish
The fitted birds could not easily reach the harness section on their own backs. A flockmate had a better angle and appeared to receive no immediate food or other obvious reward for helping. The tagged bird also had to tolerate another bird working close to its body.
Crampton and colleagues interpreted this as cooperation and moderate problem-solving. They also discussed the possibility of “rescue” behaviour, in which one animal helps another escape distress without receiving an immediate benefit.
I would be cautious about going further than the observations. The study did not measure what the helper understood, whether the harness caused distress or whether removing unfamiliar objects is part of ordinary social grooming. Calling the act altruistic gives the bird a motive the researchers could not directly inspect.
The social setting still matters. A separate 2018 Nature study led by Benjamin Ashton tested wild Western Australian magpies on inhibitory control, associative learning, reversal learning and spatial memory. Birds in larger groups performed better across the tasks, an association that emerged as juveniles developed. That does not explain the Queensland harness removals, but it gives useful context for a species that lives and solves problems among other birds.
A failed tracking trial can reveal a flaw in the method
Animal tracking has turned movements that were once invisible into lines on a map. When I wrote about a juvenile godwit flying more than 13,000 kilometres across the Pacific, the central evidence came from a five-gram transmitter. Without that tag, the record flight would have remained an inference rather than a measured route.
But a tag is never merely an observer. It adds weight, changes the feel of feathers or skin and may alter how an animal behaves or how its companions respond. Highly social species can introduce another problem: researchers are not attaching equipment to an isolated subject, but placing a new object inside a group capable of examining it.
This is why the magpie project was a pilot. Its failure to retain the trackers was not a wasted preliminary step. It prevented the same design from being used in a larger study and showed future researchers that laboratory durability is not the same as durability in a flock.
The birds changed the question
The original project asked where magpies went, whether rank or age affected their movements and whether a wireless charging station could extend GPS studies. The harness removals stopped those questions almost immediately.
Field research often changes when an animal ignores the apparatus, avoids the camera or interacts with equipment in an unplanned way. In an earlier piece on wildlife in Chernobyl’s exclusion zone, I was struck by the same broad lesson: the method determines which part of an animal population becomes visible, and its limits belong in the result.
The five magpies did ruin the planned movement study. They also demonstrated that the study design had treated the harness as hardware when, to the flock, it was a social problem sitting on another bird’s back.
That was not the dataset the researchers wanted. It may have been the more useful observation.
