Tag Archives: field biology

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.

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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…

Up-close and personality

It is my first field night in the Kalahari, and I feel like I am wearing every piece of clothing I brought with me. My body is nice and warm except for my fingers and toes. They are permanently encased in iceblocks. As hard as I try, ensconcing them in wool gloves and socks, they never seem to get warm. Most people don’t realize how low the temperature gets in the desert, but it is bone-chillingly cold.

The crunch of a raisin bag sounds across the sand, low shrubs, and thorns hanging at just the right height to leave a mark on your face. Suddenly, three furry faces appear and start prancing over to us. Three bat-eared fox (batty) pups have come to get their treat of sweet raisins. I am dumbfounded at how close they get to us. One little boy comes and pulls on my shoelaces. These animals are habituated!

I’ve studied a number of species as a biologist, from humongous (300 kg) sea lions to thumb-sized (6g) pocket mice, but this is my first experience working with an animal that you can walk right up to and follow without them running away. To walk with the bat-eared foxes as they meander through the tall, thorned bushes, gobbling up termites and caterpillars is a truly wonderful experience as a biologist and naturalist. Most science projects that study individuals aren’t able to do something like this; they trap individuals every so often, take the necessary measurements and samples, and then release the animal into its natural setting. If you want to study their social behavior, you do so at a distance (so you don’t upset any natural behavior) at the cost of interaction details.

My PhD on yellow-bellied marmots epitomized this approach. We trapped individuals every other week, took their weight and different morphological measurements, painted a unique symbol on them and let them go. I watched, from a great distance, as they played, fought, and ran from predators. My work focused on consistent differences in individual behavior — or personality — so it was imperative that I knew the animal I was watching and with whom they were interacting. This could be difficult at such a great distance and often the small details about their personality could be lost.

The batty project allows me to study these social little animals so close that I can examine how one individual differs from another without worrying about losing much detail. I can tell who is biting whom, who’s growling, who’s whining… This approach does call for an ongoing process of habituation, though, as new (wild) individuals keep on coming into the population. So, next up is to habituate as many foxes as possible. This is a slow, tedious process, but totally worth it.

A week of firsts — Stephanie

This is it, the end of my first week in the field in the Kuruman River Reserve working as a post-doc on bat eared foxes. And I must say, it was filled with first times.

To start with, despite having work in the African bush for nearly 6 years, it was the first time ever that I went out wondering on my own at night armed only with… a torch and a packet of raisins! Coming from lions and hyaenas country (and actually many more dangerous animals, I used to work in Hwange National Park in Zimbabwe), I must say it’s quite unsettling… I had to refrain from freaking out whenever I heard a noise and to convince myself that no, every pair of shining eyes I see in the beam of my spotlight is NOT something that will try to eat me or charge me!

Who knows what lurks behind each set of eyes?

Who knows what lurks behind each set of eyes?

The good thing is, you tend to relax quite quickly and rather enjoy the silence of the night with only the stars watching over you. The “bad” thing is, you also have to stay focused because you are still in the middle of the bush. There are snakes, dangerously large holes dug out by springhares and aardvarks, and the possibility of encountering scorpions or spiny mammals (you don’t want to surprise a porcupine at night!).

Now, I was talking of several firsts: here is the second one. This was my first time baby-sitting a drugged fox! As part of my work here, I have to remove radio collars from our dear batties. They are several ways to do that. Because these foxes are habituated, they come quite close to us, especially when we give them raisins! So our first plan was to lure the female Donna in a cage with raisins. It worked quite well, but we found that she fought pretty hard in the cage and I struggled to handle her from there. It’s amazing how strong these little creatures are! So for the second capture, we decided to give Ilor some sedative to lure him easily in the cage and to keep him calm. It worked perfectly. We removed the collar easily and he barely moved during the operation. We then let him sleep it off back in the cage…And there I was, sitting next to the cage for the next 2 hours, baby-sitting this cute little drugged fox. After 2 h, he seemed quite alert, and it was time for him to be set free. But he simply wouldn’t exit the trap! I had to lure him outside with some more raisins! It was half an hour before Ilor seemed satisfied that I won’t be offering more treats, and he finally wandered off in the Kalahari night, free of his collar and apparently oblivious to what just happened to him.

And here come the third first: my first aardwolf in the wild! Aardwolves (Proteles cristata) are from the hyaena family but they only eat termites and other insects. They are also quite small with black stripes on a grey coat and can erect their mane and tail to appear bigger when threatened. Anyway, I spotted him (maybe her?) in the beam of my torch and managed to get close to the rather relaxed animal. What a beautiful creature! I followed the aardwolf while he foraged for termites, and he eventually led me straight to one of our habituated fox! These two species must use the same areas as they both eat termites and there might be some sort of competition between them? Questions started racing through my mind – the possibilities seem endless — and I can’t believe this rich desert is now really my office! My postdoc is certainly off to running, happily drugged start.

Fear of the dark — Rebecca

The start of a PhD poses many challenges, and I am sure I am not alone in the fears I have… will I be able to collect enough data in time? Will I be able to answer exciting new questions? But the embarrassing fear I didn’t even consider until a few weeks before embarking on this adventure is my fear of the dark.

For my first week in the field I was pleased to learn I would accompany Keafon and Sam at night for training, so my dreaded solo trip was postponed. However, even then I began to wonder how I would ever feel comfortable with the eeriness of the dark, where strange shapes can appear and unknown noises play with your mind.

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My only protector in the dark Kalahari nights.

One week later it was time for my first solo outing. As I set out in the dark my heart was racing, but I kept telling myself, you can do this! Just for a moment, I turned my spotlight off and embraced the darkness. It was an overcast night and the blackness engulfed everything. But turning the light on and off as I pleased meant I was in control of the dark… But last night was different.

Following Ernie at high speed kept me more than occupied and the thought of the dark didn’t even enter my mind, when suddenly, my torch batteries failed. After a few deep breaths I reached into my bag and felt around for new batteries. I slowly placed them into the torch, breathing a sigh of relief in anticipation of fresh, bright light. After a small pause, I click the torch on and……nothing…….darkness. Not a problem, still another four newly charged batteries to go. Again, reaching into the bag I found the batteries and carefully placed them into the torch, but still…darkness. I could feel my heart thumping in my chest, and I wondered how long I should leave it before calling for help. All that kept running through my mind were the stories Keafon and Sam had told me about snakes. I had horrid visions of being surrounded by masses of snakes. After 15 minutes of sitting alone in the dark, desperately trying to get my torch to work, I decided it was time to call Keafon. As the car’s headlights appeared on the horizon I breathed a huge sigh of relief. My time in the dark was over.

Luckily, after only 10 days in the field, I am in love! The foxes and their individual characters are simply amazing and this adventure with them is going to make any fear easy to overcome and most certainly worth the bumpy ride of facing those fears head-on. This morning, as I sit here and reflect on my experience I am pleased my batteries failed; it forced me to face my fear and realize the dark isn’t so bad… and the feeling of being the only person left in the world is pretty amazing. I imagine there are not many places left in this world where one can have that feeling!

String pulling – The bat-eared fox story

I arrived in the Kalahari a year ago with the mission of testing the batties’ problem solving skills. They are rather small brained, so I didn’t expect too much. However, they surprised me in the first challenges I presented to them (opening puzzle boxes). Since my foxes performed splendidly with a simple puzzle, I challenged them a bit more with a harder one. Here they needed to a tasty raisin from one string with another string devoid of raisins. This would show these guys understand the connectivity of things and can reason “this end is connected to that raisin, but that one has nothing”. This is more common in birds, but rare in the mammal world. Only three foxes showed interesting in pulling strings as other resorted to their ‘know how’ of opening the previous puzzle such as trying to push the lid down. The interest was soon lost when this strategy didn’t work. After four months of seeing the three foxes pull baited strings I was finally done. One of the foxes was very smart and had a great success rate, but then immediately disappeared without a trace… The ones left behind performed a bit more poorly, just pulling whatever they see first regardless of its connection to a raisin. Well, I can’t say that these foxes don’t understand connections; so many other factors  could easily have influenced their performance, such as their reliance on listening for their food. So far the verdict is still out of how smart these guys really are. My time here has now come to an end and I will seek another adventure that was as fun and exhilarating as wild bat-eared foxes. It was a long struggle to get the foxes to like me and now I have to leave them. I know I will miss them as if they were my own.

Is the third time the charm? — Ruan

An experienced field researcher by now, I had certain expectations of my third trip to the field this year. These expectations were quickly shattered as I, once again, realised that change is the only constant. My body – used to subzero winter temperatures in the Kalahari – went into a mild state of shock when I returned to spring temperatures reaching 40°C. The heat is, quite simply, debilitating. Simple tasks like eating dinner become a battle as I try to force nutrition into my body that was already sweating like a hippo in a sauna. I have a new appreciation for nocturnal work under these conditions!

The batties have shed their gloriously fashionable winter coats and their true size – or lack of it – is now revealed in their scraggly summer fur. They are almost half the size they were when I left. The lack of rain and extreme temperatures has also resulted in some vegetation changes. The tall sour grass that used to cause several “exciting evenings” is all gone and the field is now flat, open and bare. This makes finding the foxes a lot easier and these little Houdinis are far less likely to do a disappearing act on me this time around. Last night, I had the opportunity to see a “dog” and mouse situation, where the fox I was following locked eyes with a passing rodent. What ensued was some tail-raised-dust-cloud acrobatics as Blackie was determined to put mouse on the menu. After several minutes of traversing in all directions, the battle finally ended in a faint squeak as the mouse was defeated. Blackie proudly looked around before he indulged in his glorious feast.

I am excited (and stressed) to be back with my foxes and anticipating that the breeding season is going to ensure me some interesting times in the near future… Hopefully some of these tiny little foxes will prove man enough to father some adorable pups.