Attaches Radio Telemetry Anklet to Gorilla
Apes Incorporated and the Aspinall Foundation are the first to successfully attach a radio telemetry transmitter to an adult male gorilla, a young silverback named Kush at the Port Lympne Wild Animal Park in Kent, UK. To protect against Kush’s formidable canine teeth, the transmitter was embedded in a heavy duty aluminium housing attached to his ankle using a stainless steel chain: codename.
Many people will not like the fact that we used a chain to attach the transmitter or even that we tried to attach anything at all. However, the fact is that western gorillas are now being hunted to extinction. By making western gorilla tourism both economically viable and biologically sustainable, radio telemetry could turn the tide.
Tourism has been very successful in protecting the mountain gorillas of East Africa. However, it has thus far failed to protect the much more numerous but rapidly declining western gorilla. Tourism has not been successful in large part because western gorillas walk about ten times further each day than mountain gorillas. Consequently, habituating them for tourism takes about five years instead of one year. The constant presence of trackers also exposes the gorillas to immunosuppressive stress and human respiratory viruses that cause about half of deaths in habituated gorillas and chimpanzees.
Three years ago we realized that radio tracking could radically accelerate the habituation process, driving down startup time and operating costs by as much as 80%. By drastically reducing the amount of time humans spend with gorillas, telemetry would also minimize stress and human disease spillover. Radio tracking has not been previously used on gorillas both because of anti-interventionist sentiments in the ape conservation community and because of the technical difficulties of attaching radio telemetry devices to gorillas.
How do you attach a radio transmitter to an incredibly powerful animal with effectively no neck and two inch canine teeth? The first step is to find a partner like the Aspinall Foundation, which both cares for gorillas at two parks in England and operates the world’s only successful gorilla reintroduction program in Gabon and Republic of Congo. Two decades in the African conservation trenches have given Aspinall the wisdom to understand that although testing on captive animals is not without risk, these risks are small compared to the potentially huge conservation benefits for animals in the wild. In particular, Aspinall want to use telemetry to rescue reintroduced gorillas who have wandered into areas where they are at high risk of being shot.
In our first try, we wanted to confirm that the classic “collar around the neck” would not work. We bought a collar from a commercial radio telemetry provider and tried to put on the neck of a young silverback at Port Lympne named Timibou. However, his sagittal crest, the muscles on the back of his head and neck, were so big that it just slid right over his head.
Our next effort was a belt around Timbou’s waist. Male gorillas have massive chests but tiny, ballerina waists. The belt just slid right down his bum like a pair of gangsta droopy drawers.
Mach 3 was an anklet using the same materials as the collar and waist belt. Timbou immediately smashed the high impact plastic housing protecting the electronics but the heavy duty plastic belting held.
Some experienced ape conservationists had warned us that gorillas would injure themselves trying to get an anklet off. But after a day or two of gnawing at the anklet, Timbou completely ignored it.
We’re really moving now, we thought. So we commissioned a new version of the anklet with an aluminium housing covering the electronics. After six weeks we removed the original anklet and replaced it with the armoured one. A close examination of Timbou’s ankle showed that the anklet had not caused any injury.
Even more progress!
This time Timbou ignored the anklet from the start. After a month we took it off. No injuries. Minimal damage to the anklet.
Pride cometh before the fall…
Flushed with victory we set off to Congo to test the anklet on another young silverback named Kelle. Kelle had been earlier released into the wild but recaptured when he started ranging near villages where he was in serious danger of being shot. We put the anklet on Kelle with high hopes that it could provide an early warning system. Within four hours he had ripped the antenna out. By the next day he had ripped one third of the belt away. We took it off after 48 hours.
Back to the drawing board.Where we went wrong was in not recognizing that Timbou had lost two of his canine teeth during childhood rough and tumble play in England. Lacking opposable canines, he could not bite effectively at the belting material. With an immaculate set of canines and the huge bite pressure generated by the massive halo of muscle on his sagittal crest, Kelle made short work of reinforced plastic that a human could not even dent.
This time instead of buying an off-the-shelf product from a commercial telemetry provider we commissioned a local metal shop, Mill Turn Engineering in St Ives UK, to custom build us a Gorilla Proof aluminium housing that we affectionately call IronMan. We also partnered with Microsoft Research in Cambridge, a lead institution on Mataki, a multifunctional radio telemetry system for wildlife conservation applications. We put the Mataki board into Ironman and attached it to a different silverback at Port Lympne using a stainless steel chain. Kush has canines every bit as lovely as Kellle.
After the first day Kush ignored the anklet. After a month we took it off. Ironman did not injure Kush. Kush did not injure IronMan.
Success! Really this time…
Our next step is to make modifications to Mataki that will increase the signal transmission range and save battery life. These should be done by midsummer, at which point we will go back to Africa for some ground truthing then attachment to a reintroduced gorilla. We also have two tourism companies ready to use the anklet for gorilla habituation. But that is another story…
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