De-collaring a hyena is a lot harder than collaring a hyena.
As part of my long-overdue (thanks, covid!) visit to Kenya, I wanted to attempt to de-collar the spotted hyenas that I had outfitted with GPS-GSM collars in 2019. While the collars have proven invaluable for understanding hyena movement through a densely developing landscape, as well as how to mitigate hyena interactions with people, the collars were due to run out of battery and unfortunately did not have automatic drop-off mechanisms. Thus, the mission to rid the hyenas of their fancy necklaces before the necklaces became useless.
So, how do you capture a hyena? There are a lot of animal capture methods out there, but we prefer the callback method. This essentially entails calling in hyenas using particular hyena sounds of excitement, as well as a few rather unsettling tracks I have of sounds of various other animals dying. Some veterinarians and researchers also like to use bait, though it isn’t necessary. However, since we were trying to recapture specific individuals, rather than just any hyena, we were gifted loads of slightly “off” meat (in conjunction with the callbacks) to use for enticing our collared hyenas to stick around. My friend Simon’s car, filled with 60+kg of quickly spoiling meat, became known as the Meatmobile- and yes, in case you’re wondering we did spend a lot of quality time in the sweltering heat of the car with that disgusting meat and its burgeoning, fly-dominant ecosystem. [Note, all of this work was conducted with the proper permits and using proper ethical procedures].
Once our collared hyena has hopefully responded to the callbacks, the vet gets ready to dart the hyena. Because they hyenas are accustomed to my car, sometimes the vet will end up hopping into my car to get closer for darting. Then, the dart is loosed and hopefully you’ve soon got yourself a sleepy ‘yeen ready for de-collaring and measurements.
I’ll share a few notable stories from our four days of de-collaring efforts.
One of our hyenas, collar #1623, seemed like he would be easy to capture. I had seen him chilling out in the open in his favorite spot, oozing confidence and not skittish, several times over the few weeks I’ve been back. Thus, we used a combo of his GPS collar data and UHF signal to try and find him. One day, we knew he was near the lakeshore, so we began to set up our bait in that area. While looking out onto one of the bays, we spotted a hyena. A quick look with my binoculars showed me that against all odds, it was the collared guy rather than another hyena! I whisper-shouted “It’s him it’s him it’s him” to the group and we all moved rapidly to get into place for the callbacks and baiting. Fast forward to an hour later, and he was finally coming out into the open, nearing the bait. I trained my binoculars on him, and suddenly everything seemed like it was moving in slow motion. “Holy crap,” I said, “It’s not #1623…It’s Smiley!” Smiley was a hyena (with a missing lip) that we were convinced had met his untimely end months before. His collar had abruptly stopped working right after he meandered into another clan’s territory (after trying desperately to disperse out of the conservancy in multiple directions). We were all floored by this plot twist. #1623 didn’t matter in that moment; Smiley was resurrected from the dead and we needed to remove his useless collar. Once we darted him, we were able to remove the collar, get some measurements, and check on his health. Though old, Smiley turned out to still be quite big and strong, and very clean with no parasites. He had actually assimilated into the clan that we thought had killed him (the Lakeshore/Diatomite Clan), and was doing just fine. While we didn’t catch #1623 that evening, we were all riding the high of our Smiley surprise.
We didn’t want to give up on #1623, however. So we returned on the final morning to the area where we knew he was, this time armed and ready with the UHF receiver. Nearly all of his clan-mates (minus Smiley, who seems to have decided against approaching us again…) showed up for the callbacks, except for #1623. He stayed deep in the dense bushes near the lakeshore, where it was inaccessible and possibly dangerous for us to try and dart him [we don’t like darting hyenas near bodies of water, since there’s a teeny chance they could fall asleep and drown in the water]. Eventually, we decided to just go looking for him on foot. We had two armed rangers, so we were ready for buffalo. Using the UHF, we clambered through bushes, 2 meter high grasses, and thorny acacias. The signal was getting much stronger. Suddenly, we spotted him sleeping under a large shrub. He sprang up, stared at us for a split second, and bolted into the brush. No chance whatsoever for us to dart.
We came up with a new plan: I and the rangers would use the UHF to try and flush #1623 out of the bushes toward the road. Meanwhile, the vet and team would drive on that road, preparing for him to be flushed in their direction. I went off with the rangers, UHF held high above my head, and one earphone in my ear to listen for #1623’s signal. Suddenly- BLAM. I leapt a solid foot into the air as Nicholas the ranger shot his gun. We had just rounded a small bush to see a few buffalo just 3 meters away from us. Fortunately, Nicholas’s gunshot scared them away and we were able to move in a different direction. We had been upwind of them and hadn’t been able to smell them ahead of time. The next time we came across an even larger herd of buffalo, I was ready- we were downwind and I smelled them before I heard the trampling of their massive hooves running. Fortunately on this occasion we made our way in a different direction with no gunshots necessary. At this point I told the guys that this collar was not worth our lives, and the buffalo were too many – it was time to give up on removing #1623’s collar.
That same night was our last night to try removing collars. There was one hyena we hadn’t tried yet- #1627 of the Northern Clan. Again, using the GPS locations, we chose a spot near to the Northern Clan den to set up our remaining masses of meat and get ready for callbacks. We began the callbacks at 5:30pm. Unfortunately, this clan has become markedly skittish, and #1627 turned out to be the most skittish of the lot. For 5 long hours, we tried every trick in the book to get him to come close enough for darting, and by 10:30pm we were all exhausted and morale was waning.
I can assure you the next thing that happened is 100% true. At 10:30pm, feeling desperate and fatigued from the whole process, I said to my car-mates, “Listen, I truly believe that we can manifest this into happening. To manifest, you can’t just say to yourself, ‘I want the hyena to be darted.’ You have to really imagine and picture the sound of the dart. Are you ready?” And they agreed to all imagine that sound together. I kid you not, three and a half minutes later we heard the sound of the dart. #1627 was successfully darted by our amazing vet team, and I’m convinced that our manifesting played no small part.
We ran through the brush after #1627, who was refusing to succumb to the drugs. Eventually, he did, but we still wanted to work quickly. When we got close to him, I was immediately both horrified and so glad that we had caught him – he had a huge, infected wound on his head, likely from a fight or an accident. The vet was able to treat his wound, as well as remove his collar, and she says he is likely to recover very well. While the wound was deeply unsettling, I was so grateful that we were able to capture #1627 at the midnight hour and help him in such a profound way.
This whole de-collaring process was a whirlwind that felt a lot longer than the 3.5 days that it comprised. A note here that all GPS collar companies should make automatic drop-off collars, but unfortunately that is not yet the case. So we must do our best to help the animals after they have helped us- returning to remove collars and check on your study species is the ethical thing to do, even if it is wildly difficult. Fortunately we were able to recover most of the collars deployed, thanks to an amazing, inspiring, and tenacious team.
To see some of this process in action, check out this quick video I made.