Category Archives: bat-eared foxes

End of an era…

Cylon's pupsWith the loss of many of our habituated individuals, we had long hoped that this year’s pups would help replenish our population so that the study could continue. Unfortunately, we lost seven individuals in rapid succession. Baine, one of our best individuals for conducting experiments on, disappeared with his two pups. Cylon and his three pups (already well habituated and starting to forage independently) disappeared as well. We lost all signal from their collars and searched endlessly on this reserve and the surrounding farms. We were left with one habituated fox and very little hope of finding new individuals soon. This disheartening news led to the decision that we were going to have to shut down fieldwork at this location.

 

As responsible field biologists, We (Steph and Matt) had to take off Barbie’s radio collar before we left. How would we be able to do this? Luring foxes into the large cage-traps had never really worked. When we put the collars on, we had the help of vets and large nets… but Barbie has always been quite skittish, so we had to come up with another idea. Earlier on, when Cylon had a paw caught in his collar, we successfully used a noose to catch him so we decided to give it a THE noosetry on Barbie. Because of her reluctance to get close to us, we prepared ourselves for a number of unsuccessful attempts at capturing her. We went out there, armed with a noose, a net, a little patience, and a lot of anticipation. We crept close to her in the red dune area south of the riverbed, lured her in with an abundance of raisins, humming softly to her. Slowly, but surely, she inched her way towards us. The tricky part, you see, isn’t getting her to come close to us, but to get her head into the noose without touching those big, characteristic ears. If you do, they jolt away from you and you have to retry hoping they don’t run too far away from you. This is exactly what happened…twice, but with perseverance and a bit of luck, she put her head through the noose while reaching for a raisin. We tightened the rope and rushed in to pin her down. This is for her and our own safety as she could easily bite us or get entangled in the rope. We quickly undid the screw that was holding the collar on tightly and removed the leather straps. The rope Baine's pupswas released and she ran free. She turned around about ten meters and looked at us indignantly. We didn’t mind though, she was free to go live her life and hopefully raise some pups in the future.

With any luck, by the time we start fieldwork again, she will have forgiven us and not forgotten the whistle call.

What’s next? While the foxes are running through the sands of the Kalahari, everyone will be sitting in front of their computer screen analyzing the data from the last two years and spreading the word on these charismatic batties. We will try not to dwell too much on what we’ve lost. Barbie

Stay tuned to see what we find…

Psssst….That’s My Torchlight!

A bright torchlight is a must-have for a bat-eared fox field biologist. With a bright torchlight one can easily identify the owner of a suspicious pair of eyes (particularly, owners with dagger sharp horns) and avoid walking into the grasping branches of thorny acacia thickets. Most importantly, a torchlight helps when following a battie during a nocturnal follow. Information collected during follows give us an idea about batties’ diet, territory usage, and social interactions with other foxes. I can keep the spotlight on my focal fox as it dashes up the side of a sand dune or through a maze of driedoring bushes. Occasionally, a fox decides to takeoff like Superman, and it is very challenging to keep up with them when I am only allowed to follow at a “non-threatening” speed-walk. Mostly, my torch helps me to feel safe – it makes the night almost familiar to me, and is a constant reminder of how visually-centered we are, as human beings. There is no way my other senses would compensate for the absence of my torch at night.

From the beam of my torchlight I have observed foxes locate insects by integrating information from multiple senses. Like all canids, the senses of smell and hearing are wonderfully developed in bat-eared foxes. A fox will pause, sniff, and turn its head and ridiculously large ears around before dashing off to gobble up termites, pick a caterpillar out of a bush, or even dig up a mouse hole. By turning their large ears about foxes hear even better in stereo (this is called binaural hearing) and can focus on their prey items. While the foxes’ ears and nose do help them locate insects, it doesn’t quite always give them the balance I expect. For example, on a particularly nippy winter night I observed one of our foxes, Bain, digging up ant nests. He picked around a bush, sniffing and swiveling his ears about before pouncing a bush and digging it up. A couple of times he dug too deeply for ants, and then fell head-first into the deep hole he had just dug. It was impossible not to laugh!

Avoiding trouble by finding batties in daylight...

Avoiding trouble by finding batties in daylight…

During a follow a fox sometimes spends just as much time patrolling its territory as it does foraging, and possibly a fox uses smell to locate familiar places in their territory. Just as I use a torch to light up the night to make things familiar to me, fox urine is quite useful when marking over other fox pee or on termite foraging patches. Ilor, in particular, travels several kilometers during a follow. He will urinate on a random interesting spot after sniffing it, then another spot, and another, and so on. Occasionally foxes are known to wee on researchers boots or research equipment as well. This is how my field torchlight came to smell. I had set down my torch to feed Ben raisins, but Ben had other ideas. He came up to the torch, sniffed it, lifted his leg, and “pssst,” my torch now stank of battie pee. I still am not sure if I should be offended or happy that Ben claimed me as his own… I of course later sanitized my torch, but I still advise not smelling it too closely.

Threesome at Pharside (A tale of 3 foxes)

Escobar

Escobar, but no Emmental

On a cold winter night, I was walking around Pharside Dam as I wanted to just check in on Escobar (one of our habituated males) in the area. After I called for about 5 minutes, he pitched up from behind a grassy patch and waited for some raisins. Happy that he was looking so good, I left Escobar around and started my search for Emmental, the other habituated male in this part of the reserve. We hadn’t seen Emmental for a while despite searching on a regular basis, so alarm bells were starting to ring. My steps took me on a big loop in the area, without much luck.

As I was walking back on the road, I spotted eyes in the distance. I took my packet of raisins out and crinkled it, hoping this pair of eyes belonged to one of “our” foxes. It was indeed a habituated fox, but not a battie! It was Ray, the Cape fox (yes, they all come with name tags)! He came running at me for some raisins. With winter on us now, foxes are all super eager for this treat! I stayed with Ray for a while when Escobar found us again.

Ray, the Cape fox, looking hopeful and apprehensive.

Ray, the Cape fox, looking hopeful and apprehensive.

I was getting rather excited and curious about how these two species will interact. Batties are slightly bigger than Cape foxes, and from the few interactions we have witnessed, they seem to be dominant. As usual, Escobar chased Ray away immediately. Definitely, these raisins were his to eat! He had to stay on his toes though, as Ray kept hanging around, hoping for a lucky raisin, and it was only Escobar’s growling and puffed-up tail that stood between him and the juicy treat.

Escie defending his stash

Escie defending his stash

But Pharside still had surprises in store for me that night, as another batty suddenly approached. To my delight it turned out to be Emmental! He was looking extremely healthy and robust compared to Escobar, so I was certain Escobar would now have to give up his stash. Escobar thought so too. He crouched down, growling, tail raised and puffed up, in a very submissive position. But within a fraction of a second, the tables were turned. Escobar jumped up and started a fierce fight with Emmental, eventually winning and chasing the bigger fox away. And for the next 30min, I was in the company of these three foxes.
When Emmental finally started to drift away, I simply could not follow him, as both Ray and Escobar were on my heels! It was a very peculiar stand off, with both of them circling me whenever I paused for a second, and Ray trying to keep his distance form Escobar. I was impressed by Ray’s tenacity.

Walking back to the car, I started wondering. How is dominance established between batties? Is the hierarchy stable or variable through time? What are the benefits of being dominant and the costs of being subordinate? Is it access to the best foraging spots? Or to more mating opportunities? These animals tend to forage together so socially – is there even a proper hierarchy? Is there any way that a Cape fox could beat up a battie? And I realized I had my work cut out for me: I need to habituate plenty more foxes during a very cold, long winter…