Unfortunately for researchers, Australian magpies have united in foiling humans' plans, helping each other rid themselves of tracking devices. When researchers put the trackers on the birds, they expected to learn something about their behavior – but witnessing an unprecedented example of avian altruism came as a surprise.
Miniaturization has allowed researchers to place GPS trackers on animals once considered far too small to carry them, leading to an abundance of data about animal movements. This information isn't just to satisfy human curiosity – it is often essential for saving endangered species. Nevertheless, as Dr Dominique Potvin of the University of the Sunshine Coast and co-authors acknowledge in Australian Field Ornithology, it comes with ethical issues.
“Some animals seem really undisturbed by the trackers, others seem to hate them,” Potvin told IFLScience. “You can never really predict how [a new species] will respond. That's part of why we do pilot studies.”
It is generally thought small and medium-sized birds can't carry these trackers comfortably. Not only would it be unethical to weigh them down with more than they can comfortably carry, but as Potvin noted; “It's bad science” to treat as representative an animal whose behavior is changed by the tracker's weight.
This has prevented ornithologists from putting trackers on most members of the passerine family. However, Australian magpies (unrelated to northern hemisphere magpies) are passerines so large and intelligent many people assume they are corvids, and ought to be able to carry trackers undisturbed.
Consequently, researchers decided to put trackers on these Australian icons – but with a twist. To avoid having to capture the birds twice, the team designed a harness containing a quick-release mechanism causing the trackers to come off when near a magnet.
The plan was to place a powerful magnet near a feeding station, releasing the catch when the time came. The same station also had devices nearby that could wirelessly recharge the batteries and download data, cutting down battery and data storage requirements.
The team was very proud of their creation, Potvin told IFLScience – but they had not counted on Australian magpies' combination of intelligence, social behavior, and apparent privacy preferences.
Almost as soon as they were released, the magpies started pecking at the trackers to get them off. This was a hard task on their own, but Potvin's team then witnessed other magpies come in to help, pecking at the harness until they found the point of weakness and freed their brethren.
Within three days all five tracked magpies were freed, although in most cases this occurred too high up for the team to witness the process. This also meant, Potvin ruefully told IFLScience, expensive trackers were not retrieved.
Although they did not get the data they were hoping for, the team arguably got something more important. Reports of altruism – helping another without immediate reward – are almost non-existent in birds, but it appears to be the only explanation here.
The release examples the scientists witnessed involved tracker-bearing magpies freed by untracked counterparts, indicating it was not a case of “you remove my backpack, I'll remove yours.” Instead, some birds apparently saw family members being bothered by something and came to help.
The team also suspect – although lack sufficient examples to be sure – that the birds showed problem-solving skills, identifying the single weak point in the harness where it could be separated relatively easily and targeting it. This would confirm the magpies' suspected intelligence. It is likely this intelligence and the strong social bonds that cause members of their groups to help each other are related.
Potvin told IFLScience the team will cry a bit about the failure of their brilliant harnesses, then “shake ourselves off” and seek to apply them to other animals who may resent them less, like lizards.
“With the magpies we will wait until the trackers can be made even smaller, so perhaps they will bother them less,” she added.
The discovery of their altruism and likely intelligence makes the magpies even more tempting subjects for researchers. Moreover, just days before the work was published, other research showed Perth heatwaves are wiping out young magpies, suggesting the currently abundant species is vulnerable to climate change. This, Potvin pointed out in The Conversation, makes finding better ways to learn how magpies respond to changing conditions, as the trackers were designed to do, more urgent.