fieldwork

Tracking down an African wild dog den

The winter months of June, July, and August mark the coldest period of the year in Northern Botswana. It is this cool period that African wild dogs choose for whelping, as pup rearing is energetically costly for a pack. Typically, the dominant female looks for a suitable den site, such as an abandoned aardvark hole, where she will give birth. As the mother is obliged to stay at the den to nurse and protect the pups, so the survival of both the mother and pups is fully dependent on the other pack members during this critical period. The rest of the pack all leaves the den site once or twice per day to go hunt, and upon returning, they regurgitate part of their freshly caught meal to feed both mother and pups.

During the denning period, the normal ranging radius of a pack is drastically reduced. Consequently, denning season is the optimal time of the year to locate the study area packs and for pack monitoring. This July we tried our luck to locate the den site of the missing ‘Mula’ pack. This pack was formed in February 2016 by the joining of a male dispersing group with a female group, each of which we had monitored with satellite collars as part of our ongoing research project on African wild dog dispersal. However, these satellite collars both had dropped off by now. As we are also interested in the settlement and reproductive success of recently formed packs, it was critical to catch up with this pack again.

Having no working radio telemetry collars on the pack we were left with no other option than to track down the pack on the ground the old-fashioned way. We already knew that the new Mula pack’s home range extended from Xakanaxa all the way east along the Khwai river to North Gate of Moremi Game Reserve. This meant they could theoretically have been denning anywhere within about 400 km2 and along a stretch of about 50 km. We decided to start our search mission in Xakanaxa where frequent sightings of 12 wild dogs had been reported on the sightings board at Moremi South Gate. The last time we saw ‘Mula’ pack, at the end of 2016, they were ten adults plus two pups. Therefore, these reports sounded promising.

With enough supplies to spend a couple of days away from our research camp, Ed, a Research Technician at Botswana Predator Conservation Trust (BPCT), and I set out for the 50 km drive to Xakanaxa. Upon arrival, we bumped into some safari guides who told us that they had regularly seen a pack of 10 wild dogs and one male was wearing one of our radio collars. Luckily, one of the guides had just seen the pack earlier that morning. Using this information, we started looking for fresh tracks on the main road and soon found some. The prints were following the road for roughly 3km but eventually they left the road and we lost their tracks. We decided to park our LandRover close to a crossroad to see if the pack would use the same road on their way out of the presumed den site for the evening hunt.

Our car parked next to the road in anticipation of the ‘Mula’ pack coming along on their way out of the presumed den site.

Being impatient, we left our lookout before sunset and looped around to the North the nearby Paradise Pools to search there. With no success, we drove back to the crossroad to find out that the pack had just come by, as indicated by the many fresh tracks on the road. We rushed following the tracks and caught up with the pack shortly after. They were spaced apart and due to the progressing darkness, we were not able to count more than eight individuals. As we were taking photos of them for identification, one of the dogs who was lagging behind suddenly turned back and sprinted down the road toward where they just came from. We followed him as we guessed he might have changed his mind and decided to return to the den. He ran down the road at full speed, coming by our stake out place at the crossroad and then continued heading further south. Then suddenly, he turned east into the thick mopane bushes. It was too dark for us to try to follow him through the thick vegetation, we took a GPS fix of where he turned off and went off to find a suitable spot to spend the night. Later that evening we confirmed by examining our photos, that these were indeed the remaining members of ‘Mula’ pack.

Our first encounter of ‘Mula’ pack as they were trotting along to road for an evening hunt.

Early the next morning, we positioned the vehicle again at the crossroad in hopes that the pack would come by again. Unfortunately, no dogs appeared and we had to conclude they must have chosen a different route. Just as we were about to leave, another game drive vehicle pulled up and told us they had just seen the dogs back on the airstrip again heading east – which meant towards where we saw them last night. In anticipation that the dogs would continue running in a straight line, we drove south on the main road and parked close to where the extension of the airstrip would intersect the road. Luckily, we were at the right spot as a group of six of them came out of the thicket and crossed the road. We immediately followed them into the bush. Despite many obstacles, we managed to stick with the dogs for roughly 300m. But then, suddenly, we lost them in a relatively open area. We got out of the car and started looking for fresh tracks. There were quite a few prints on a small game trail. By following them, we ended up in a sandy rift with spaced out apple-leaf trees. Unfortunately, the sand was very deep which made it hard to surely identify any of the many tracks as being from wild dogs.

A subgroup of ‘Mula’ pack crossing the road on their way back to the den site

For the next three days, we continued our search but never managed to close in further to the potential den site. We usually lost track of the dogs in deep sand. As we were running low on supplies, we eventually decided to head back to our research camp. But this didn’t mean that we were giving up. Too close were we in finding the den site to call our mission a failure.

One of the identification photos we took of the ‘Mula’ pack dogs after we bumped into them early one morning.

A few days later we drove back to Xakanaxa early in the morning accompanied by ‘Tico’ McNutt, founder and director of BPCT, who has decades of experience in tracking wild dogs. He seemed quite confident in finding their den based on our preliminary efforts in narrowing down the search area. As we approached Xakanaxa, we drove to the spot where Ed and I lost sight of ‘Mula’ pack previously. Tico got out of the car with Ed and me following. He first circled around the spot in a wide loop in search of any fresh tracks. Once we closed the loop he headed for the direction where he must have seen the most promising tracks. Shortly after, he showed us fresh dog tracks and pointed towards the direction they were leading. After about 1.5 km we approached an open sand ridge. Tico told us to stick close together as he was confident of the den being nearby. We followed the fresh tracks in deep sand, and as we were approaching a few apple-leaf trees we suddenly heard the alarm bark of a wild dog. This was undoubtedly the den site we had been looking for. We crouched down but weren’t able to get a visual of the dog as the trees were quite dense. We decided to take a GPS fix and return with the vehicle.

Impressed by the way Tico tracked down the den in no time, we started heading back. After a few steps, he stopped and showed us animal tracks in deep sand. What seemed like it could have been any track to Ed and me, was definitely the spoor of a wild dog according to Tico. He pointed out that he could detect wild dogs in deep sand based on their gait. Two feet are always placed close together with a bigger gap between the next set of pads whereas the step lengths of hyena prints are generally more regularly spaced. This was an important lesson for us and definitely made the difference as Ed and I were constantly losing the dogs in soft substrate during our previous search efforts.

Wild dog tracks (left) are not always as distinguishable from hyena tracks (right). As the substrate gets softer, details of the paw vanish quickly. We learned from ‘Tico’ that it comes down to look for gait patterns such as spacing between the footprints in deep sand.

On our drive to the newly-discovered den site we were not able to see more than half a dozen of the adult dogs nor to get a visual of any pups. But when Ed and I drove back to the den a few days later, we managed to identify all ten adults, the two yearlings, and watch twelve new-born pups play youthfully outside the den. It was well worth the effort:  No dogs had died since our last detailed encounter with the pack seven months ago and a promising number of pups was about to grow up.


Watch the ‘Mula’ pups as they emerge from the den:

 

Find out more about this project by visiting our research page:
African wild dog dispersal and demography

Kalahari – Through the Eyes of an Engineer

by PRITISH CHAKRAVARTY

Having lived my entire life in the Northern Hemisphere amidst humans, it was with a heady concoction of childlike enthusiasm and amazed disbelief that I made my way through 31 hours of buses, trains, flights, queues, halts and drives to the Southern Hemisphere to spend two weeks with animals. I keep having to pinch myself from time to time to check if these dreamy places my academic pursuits carry me to are not just wishful figments of my imagination – first Switzerland, then California, and now the Kalahari desert in South Africa! Three continents! With shining eyes, I watched from the very edge of the car seat as my inward excitement seemed to be reflected in the gloriously red sunset illuminating two gigantic halves of the sky – one serenely reflecting the receding rays of the summer sun (summer in February! Something I hadn’t even dreamt of experiencing!), and the other ravaged by a colossal storm split open every so often by humongous lightning strikes. Here’s a picture of how the sky looked like from my car window (did not manage to get the lightning strikes in this one though).
1 Zeus was kind enough to send forth a gargantuan welcome

My PhD is about understanding the process of dispersal in meerkats using inertial sensors such as accelerometers, magnetometers and gyroscopes. The idea of extracting meerkat behaviour just from signals recorded on these sensors fascinates me, and I could have spent 4 years immersed in this world of signals, processing techniques and interpretations. But to have the unbelievable fortune to go to the very place these signals come from and actually see wild meerkats prancing about in the sands of the Kalahari desert, creating new dispersal strategies and group dynamics in real time in their own environment and according to their own mysterious rules, is something that makes me send out intense beams of gratitude into the universe every now and again. The Kalahari Meerkat Project is situated at the Kuruman River Reserve – a river that last flowed about a 100 years ago now lies as a flat bed surrounded by different shades of sand (whitish to yellowish to reddish) and low, flat dunes dotted with thorny shrubs and acacia trees. The first picture below shows the Kuruman river bed, and the second one shows the typical landscape seen in this part of the Kalahari.

2 The flat Kuruman river bed

This place is home to a mind-boggling assortment of desert fauna such as meerkats (charismatic creatures who seem to be in a perennial state of urgency), warthogs (Pumba!), desert squirrels (rather arrogant, look like balloons), leopard and tented tortoises (named so because of the respective patterns on their shells), bat-eared foxes (which surprisingly almost exclusively eat termites; they’re nocturnal and prefer periods of lower temperatures; they’re currently being ravaged by an outbreak of rabies in the region), aardvarks (phenomenal diggers that use the three huge claws on their paws to create holes 1.5 – 2m deep!), porcupines (also great diggers that find a juicy shrub-root, dig into the sand to reach the tuber, and eat the plant from the inside out), and pangolins (so elusive that even experienced field biologists there had seen just 3-4 in their time).

Coming to the ungulates, there are springbok (identified by the white underbelly), steenbok (identified by the big ears and smaller size), hartebeest (similar to steenbok, but usually much bigger in size and with less prominent ears), gemsbok (huge antlered beasts almost as big as adult cows but more muscled and mobile, also known as Oryx, which by the way is also the name of the entertainment software in Qatar Airways flights), wildebeest, duiker (a kind of antelope), some common elands (second largest antelopes in the world, after the giant eland), and giraffes (introduced artificially by some farmers here). There are also African wild cats, spring hares (look like miniature kangaroos, are actually rodents), and wild hares (usually nocturnal, and go toing-toing-toing as soon as you catch them in your car headlights).

Birds include pied babblers (named so because t4 Huge ostrich egg, no banana for scale, sorryhe sound they make resembles ‘babbling’), yellow-billed hornbills (unexpectedly heavy – I was sitting on the branch of a tree near the Farmhouse writing down my observations of the day when I almost toppled over because the branch started shaking suddenly even though there was no wind. I looked up to see that a hornbill couple had landed on the end of my branch and were probably deciding whether I deserved to sit on the same branch as them. In hindsight, the branch probably moved so much because of the greater torque resulting from the big radius arm, since they settled at the end of the long branch), ostriches (when they run with the car you’re driving in, it looks like a scene from Jurassic Park – the claws on their feet look just like those that the velociraptors had! Their huge eggs are shown in the picture below – unfortunately I did not have time to put anything for size-reference – the mother was running after us!), and many others I do not know of.

 

Coming to the insects and crawling creatures, there are vibrantly coloured grasshoppers, burrowing skinks, millipedes (one’s shown in a photo below – the tracks of its two rows of legs can also be seen in the sand just behind it). They’re coated with a poisonous substance so that they can’t be readily eaten. But the clever meerkats roll it around in the sand first so that the poison is scrubbed away, and then they happily devour it), and scorpions (4 varieties, of which 2 are very poisonous).

Reptiles include cape cobras (I was very surprised to see that they are orangish-yellow in colour!), puff adders (rely on stealth for hunting. Move very slowly and stay camouflaged in a single place for a long time waiting to pounce upon unsuspecting prey. When humans unwittingly go near one hidden behind a bush, they make a loud hissing noise. Rather funnily, sometimes when volunteers yawn near meerkats, they alarm them since the yawn ends up sounding like a puff adder hissing sound!), and big yellow-and-black monitor lizards.

Nature’s canvas drapes over you with its innumerable colours when human ‘over-presence’ does not stifle its palette. This was the first time I saw the Milky Way the way it is shown and described in books on space – a cloud of stars stretching across the night sky in a splendid disk of bright light. Extrapolating that disk across the entire surface of the Earth made me marvel at the scale of things, and how exquisite this force called gravity was, keeping us bound to the surface so that we don’t float off into the black nothingness that the stars were pinpricks on. When you close your eyes at night, do you also have several doors and corridors between you and the peace you are trying to seek? During sundowners (drinks with friends atop a dune during sunset), I closed my eyes and all the doors and corridors disappeared, and each long, slow breath seemed to be a conversation beyond words with everything around me – the hot sand, the amusedly twinkling stars, the hope of coolness in the wind, the barking geckos, the scrabbling insects, the hooting owls… sending busily chattering tingles down my spine. Another thing that struck me was the sky during daytime. The trees here aren’t very tall, the region here is pretty flat, and the only tall human construction for miles around is a solitary fire tower towards the east of the reserve next to Botswana Road. This means that you can see the horizon around you in every direction! Here is a picture of one of the sundowners we did at Big Dune (the tallest dune on the reserve, situated right in the middle, to the north of the Farmhouse (where the ‘meerkaters’ and ‘moleratters’ lived) and west of Gannavlatke, or GV (where the ‘squirrelers’, bat-eared fox people, and we lived)) below.

9 The limitless wealth of the Kalahari churns out one beautiful sunset and sunrise after another

Being surrounded by field biologists was simply exhilarating. Every comment and word floating around me carried a new and exciting snippet of information about this foreign land with its exotic vegetation and creatures that had hitherto only existed on the National Geographic and Discovery Channels for me. For instance, I had no idea that acacia trees have roots that are 20-30 m long so that they can reach the water reserves below and thrive; the trees themselves are about 10 m tall, which means that most of the tree is actually underground! Babbler Jess, the multi-talented bird nerd told me this.

Going out to the field with Gabriele felt like having a heavy-duty torch in pitch darkness. Having spent his entire PhD in the jungles of Botswana working on wild dogs, and then several years as a postdoc working on lions, bears and butterflies, he has an amazing eye that scours the surroundings for little clues that nature slips out every now and again to tell you what it’s up to… if only we could pay more attention! Searching for meerkats, he would suddenly stop at some tracks on the ground and tell you that a puff adder had slithered by not too long ago. Or how a burrowing skink had dug its way through the sand, emerged at some point, and then gone back down in another direction – just from the tracks! Or how a particular part of the reserve was slightly greener, because it had rained some days ago there (rain in the Kalahari is very localized!). Or whether someone had driven past a while ago on the same road, or why it was completely devoid of car tracks (because one of the caretakers had driven along that road with a tyre dragging behind to smoothen and flatten it). Here’s a picture of a road in the reserve. Some of these things seem like logical conclusions in retrospect, and one would maybe have been able to infer them if one were paying attention to that particular thing. But one has to bear in mind that the ‘only’ goal of our drives through the reserve was to look for meerkats, and these insights came while everyone’s eyes were peeled to catch a glimpse of the meerkats. Noticing these ‘extra’ things while your mind is centred on something else is something that is hard to do, and probably comes with you simultaneously looking for these supplementary little things over a long period of time – the mark of hours and hours of experience in the field. I felt very lucky to be in the presence of someone so knowledgeable and experienced, and to be constantly nourished with these little snippets of information that taught me the language nature was speaking to us all in. Here’s Gabriele on a fence, waving the antenna around, trying to catch the signal from the RF collar of the meerkat we were trying to find that day.11 Gabriele scouting for an elusive meerkat

 

One morning, as we were driving past one of these fences, we suddenly heard a strange thumping noise on the wires. Gabs stopped the car and we spotted a duiker caught helplessly upside down on the fence. It had tried to jump over it, and one of its hind legs had gotten caught in the two uppermost wires. It must have swung down due to the impact, and even its neck had gotten stuck between two of the lower wires. As we rushed out from the car towards it, we noticed that the wires had drawn some blood as well. We immediately set to work freeing the poor duiker which was now shrieking in fear since it probably thought we were going to kill it. Those desperate, helpless cries were heart-wrenching, and trying to imagine how close to death the trapped animal must have felt as we approached it rattled my bones. With clippers, Luc slowly cut the wires on the fence binding her (under Gabs’ directions) as Gabs held on to her front paws so that she wouldn’t kick out and injure the people trying to free her. To calm her down, Gabs suggested we cover her eyes, so I took off my shirt and covered her face with it and she finally stopped shrieking frantically. I then jumped over the fence to hold her third paw steady and then slowly eased it out of its death trap. Then cautiously, gently, we eased her out of the fence on my side and backed off as she somehow found the strength to get out and gingerly run away with numb, bleeding legs. An unforgettable experience!

Clouds during the day are a relative rarity in the Kalahari, but when they do come by, not only do they offer some welcome respite during tracking, but they also lead to some breath-taking sunsets with the bright sand reflecting even more light onto the clouds. They seem to hang much lower than anywhere else I’ve seen (maybe because there was no sufficiently tall reference for scale, such as the Alps outside EPFL), and I felt that if I managed to climb a tall enough tree and threw a stone really hard, it might have pierced the lowest cloud! Of course that’s not true (but maybe gemsbok meat gave me superhuman strength and I just don’t know it yet), and I wonder if there is actually some meteorological phenomenon that makes these clouds hang so low.

A typical day would start off even before the crack of dawn, since getting meerkat-weights as soon as they woke up and shuffled out from their burrows was very important for other parallel studies looking at weight-variation with various parameters such as vegetation, meerkat life-history, age, group, climate, temperature, etc. We would wake up at 4:30 am ourselves, I’d fix myself some breakfast and Gabs and I would leave the house at 5:10 am, reaching the Farmhouse 4 km away at 5:20 am (this 10-minute would often be quite silent, spattered with occasional exclamations of ‘Oh God, I could sleep some more’). At this time, it was usually still pretty dark, and all we would see were just silhouettes of trees in the backdrop of a sky which had just pressed the snooze button.

This was ‘field o’clock’, and it would change depending on the time of the year and when the earliest meerkat group would wake up. From the Farmhouse, we’d leave at about 5:45 am, armed with sunscreen lotion (called ‘suncream’ by the Britishers), sunglasses, heavy-duty boots to guard against the thorny shin-level bushes, and a water-bottle. It’s quite surprising how we don’t realize how much and how soon we get dehydrated there – it’s so dry that I never sweated; the only tell-tale signs I would notice later were thick traces of s
16 Portable ultrasound to document pregnanciesalt on my T-shirt and shorts from all the perspiration that quickly evaporated. We would reach the burrow at about 6:10 am and stay there till the meerkats woke up. Then we would take their morning weights, encouraging them to climb the weighing machine pan by using little pieces of boiled egg and water from a bottle. The pic below shows Peter taking weights right outside the first burrow I visited. A big part of the field biologists’ work is to habituate the wild meerkats to the researchers’ presence so as to facilitate basic important tasks such as weight-measuring and ultrasounds on the females to see if they’re pregnant. Here’s a picture of Peter doing an ultrasound at the same burrow while Nino looks on.

 

There is a huge temperature variation in the Kalahari. On the first morning at field o’clock, after the huge storm the previous night, the temperature was 14 degrees Celsius. A few days later, while doing some measurements with the magnetometer on the tracking device, I recorded a temperature of 58 degrees Celsius in the Sun at midday, and 43 degrees Celsius in the shade! A difference of about 40 degrees Celsius on the same day… mind-boggling! In the winters, the temperature can drop to about -15 degrees Celsius. I did not have a fan in my room, but since I was mentally prepared for the heat, the discomfort lasted just a few moments at the beginning of the first night. I actually slept quite well – the human body can adapt to so much! In the moments when it was the hottest, and the Sun would penetrate even the layers of laboriously applied suncream and start cooking me alive, I would think of the legendary nomadic Saan bushmen who lived in these parts as hunter-gatherers up till about a hundred years ago. Thinking about how they derived water from the little roots and tubers and leaves in the ground, and walked barefoot on the boiling sand made me forget the heat at these difficult moments, and I would almost laugh at my small discomfort.

Meerkats are charismatic animals. Frankly, if an animal’s favourite food is scorpions and it is specialized in biting the sting off a scorpion before happily munching it, it easily qualifies as a very cool animal in my books. They are intelligent creatures who, from time to time, exhibit very human reactions. They always seem to do things with a definite sense of purpose, and a small group of 4-5 on the move resembles a well-organized military unit – they will scurry in one organized movement in a particular direction, then stop suddenly, stand up on their rear legs and survey the surroundings around them for any dangers or possible paths to follow, and then take off again. They have very keen long-range vision, and when they look up in alarm and lie down flat on the ground, you can be sure it’s a raptor (biologist’s term for bird of prey. How cool is that!) even if you can’t see one immediately. The most feared raptor is the magnificent martial eagle (Babbler Jess’ favourite bird) which I had the exceedingly good fortune of seeing right on the last day on the drive from GV to the Farmhouse with Gabs and Rebecca. A wingspan of 2-3 metres and perfectly orchestrated, calm and graceful movements made it one of the most elegant animals I saw at the Kalahari – it was like watching Federer play a backhand down the line. Anyway, sometimes the meerkats think they’ve seen a raptor, and they scurry to lie flat on the ground, but then it turns out to be a vulture (which scavenges, doesn’t hunt), so then they start breathing easy once again.

20 Lone ranger 18 'Hakuna Matata, my friend!'Individual meerkats are identified by specific dye-marks put on them by the volunteers, and also (since the dye-marks wear out within a week), by a tiny transponder chip inserted into their body when they’re very young. Here’s a picture of Jules with the Jaxx group, where the dye-marks are particularly prominent. Note for instance the two meerkats on the right in the picture below – one of them (entering the burrow) has a dye-mark on the back, and the other (exiting the burrow) has two, one on the base of the tail and the other along the tail.

When a new collar has to be put on, or a blood sample has to be taken, or an X-ray needs to be done, the meerkats have to be captured (taken by the tail and put into an opaque sack so that they can’t see anything and hence calm down). They are then anaesthetized using a gas mask, and then these various tasks are carried out. Whenever they’re captured, hydration shots are injected into their muscles to keep them in good health. As a general rule, a given meerkat is never captured more than 4 times a year (to prevent de-habituation). The picture below shows an unconscious meerkat with a collar containing the inertial tracking unit.22 Comfortably numb

Even though this was just a short 15-day stay in the Kalahari, I saw and learnt so many new things, met so many new people, made so many new friends, and had so much fun cooling off in the pool, playing volleyball, having coffee conversations at GV every day, climbing trees, going for sundowners, feasting at braais (Afrikaans for barbeque), eating the best steak ever at Van Zylsrus hotel, having everyday food consisting of [vegetarians skip this part] springbok, eland, hartebeest or gemsbok meat, or beef, that it seemed as if I’d spent a much longer time at the Kalahari – so complete was my experience. I can’t wait to get back out there after 5-7 months and test the algorithms that I’m going to write in the interim. Here’s a picture of the ‘dispersal team’: from left to right – Nino, Luc, Gabriele, me and Peter.

23 The 'Dispersal Team', from left to right - Nino, Luc, Gabriele, me, Peter

I think this visit also helped me define one of the important things I want to do during this PhD, and perhaps what to go into after it. I want to combine this field experience with the technology and data analysis techniques that I have learnt and am learning in engineering to answer research questions in the domain of population dynamics, and eventually, animal conservation and management. It pained me to see that the analytical techniques employed in field biology are about 20 years behind the cutting-edge in say physics or computer science. For instance, I believe that if the level of data analysis techniques currently used in particle physics (case in point – direct detection of gravitational waves at LIGO up to an accuracy of one part in 10^21… like measuring the width of a human hair at Proxima Centauri 4 light years away!) could be complemented with cool biological insights from the field, we could answer some critical questions regarding animal movement and management, and help preserve biodiversity and bring about mutually beneficial human-animal coexistence before it’s too late. I think my PhD is already part of this vision, and I am really looking forward to doing my best to bring it to fruition!

 

Second field season started at the Alpine Marmot Project

Welcome back to the Natural Reserve of La Grande Sassière where the second field season on alpine marmots started 3 weeks ago. Whereas last year at the same period there was deep snow (1m40), we arrived in an almost snow-free area.

DSC01566

As some of you enjoyed the mild winter, it seems that the marmots did too. Survival rate of the juveniles has never been that good: we already caught 90% of them! Even the lightest one, that was 165g last year survived: it is now 900g and it is running and playing all around with its 4 brothers and sisters!

_IGP4537 copie

To deal with energy limitation, individuals have to adjust their energy balance (energy acquisition vs. energy expenditure) to maintain their homeostasis and maximize their fitness. Among all mechanisms, thermoregulation represents the highest energetic cost in endotherms. My research project focus on the role of hibernation in the life history of the marmot. To understand how hibernation patterns are adjusted to environmental conditions, we are following the body temperature of 33 individuals since May last year with loggers placed in the intra-abdominal cavity. We already caught 20 of them. Cannot wait to download the data from these loggers! Some preliminary results below… Looks great, does not it!

hib marm

Have a look to our blog in 3 weeks to know how the field session ended, and come back in few months to know more about the mechanisms underlying critical trait-demography relationships of the Alpine Marmot!

Take your time, settle down, if you want you can…return

Well, sometimes it is about fathers and sons, but sometimes it is also about sisters and unrelated males to find each other and settle down…

Three months after the beginning of our fieldwork we finally recorded our first long-range dispersal event. Following aggressive eviction from the natal group, a dispersing coalition of five subordinate females joined a group of unrelated roving males and left the core study area. The newly- formed group went undetected for several weeks until Nino found one of the coalition members (VLF152) …back on the reserve where she was captured and collared 5 weeks before. Interestingly enough she wasn’t with any of her original coalition partners and instead paired up with two newly evicted sisters.

Dispersal event of one female (VLF152) from the five-members dispersing coalition showing a typical migration pattern (see Bunnefeld et al. 2011, Börger and Fryxel 2012) as represented by the increasing and subsequent decreasing distance from the site of capture (origin). VLF152 returned home after a 25 km round trip lasting 31 days. The other four coalition members have not returned and possibly established a new territory (red circle), following a typical dispersal pattern (left side of the blue dotted line) characterized by departure (1) roaming (2) and settlement (3).
Dispersal event of one female (VLF152) from the five-members dispersing coalition showing a typical migration pattern (see Bunnefeld et al. 2011, Börger and Fryxel 2012) as represented by the increasing and subsequent decreasing distance from the site of capture (origin). VLF152 returned home after a 25 km round trip lasting 31 days. The other four coalition members have not returned and possibly established a new territory (red circle), following a typical dispersal pattern (left side of the blue dotted line) characterized by departure (1) roaming (2) and settlement (3).

But where were the other four sisters? Did the coalition simply split or did the other die? Or did they settled down somewhere with the males? But if so, why did VLF152 “return home” instead or remaining within them? Is this because, even within the new group, she was occupying a low rank and had therefore no chance of reproducing (for only one female, the dominant female, reproduces within a group)? We are currently trying to find the other four females to answer some of our questions. Knowing the where about of VLF152 – information that we can remotely download from her GPS collar – should help in this task since we can restrict our search radius.

This dispersal event adds to the previously collared individuals. At present, three dispersal coalitions returned to the natal group, one female returned to the natal group after her coalition partner got hit by a car but got evicted again, three coalitions are still dispersing and one single disperser got predated by a raptor. We thus recorded two cases of dispersal-related mortality. These movement data will allow us to investigate the influence that individual traits (e.g. age, size) but also the environment and the social spatial context (i.e. the distribution of territorial groups) have on dispersal patterns and dispersal success (survival rate and settlement likelihood).

Preliminary movement data from eight dispersing coalitions fitted with GPS radio collars. Each color represents the trajectory of a different dispersing unit in (A) the environmental landscape and (B) the social context. Note the long-range dispersal event southwest of VLF152 (violet/pink)! In (B) a utilization distribution map for the main study area is created based on the location of territorial groups (warm color= high encounter likelihood, cold colors= low encounter likelihood); long range dispersal event may end in areas where the social context is unknown (white)
Preliminary movement data from eight dispersing coalitions fitted with GPS radio collars. Each color represents the trajectory of a different dispersing unit in (A) the environmental landscape and (B) the social context. Note the long-range dispersal event southwest of VLF152 (violet/pink)! In (B) a utilization distribution map for the main study area is created based on the location of territorial groups (warm color= high encounter likelihood, cold colors= low encounter likelihood); long range dispersal event may end in areas where the social context is unknown (white)

!!!   Merry Christmas from us all and a successful 2014   !!!

Well begun is half done

After 5 weeks spent in South Africa it is time to draw the first conclusions regarding our new-born project on dispersal in meerkats. I do not want to sound presumptuous but I feel confident saying that this trip has been a great success. And as you know…well begun is half done. But let’s start with some facts from the field.

After few days spent testing the new collars and equipment, getting familiar with the terrain and the road system on the reserve, and getting to know all researchers and volunteers working at the Kalahari Meerkat Project, things got suddenly hectic when one morning we received a radio call from Teja (one of the volunteers) saying that she sighted a female evicted by her natal group a few weeks before being chased by some members of the neighboring group. We could not miss that chance, our first evicted female!

A breathing mask is applied over the head of the meerkat while it is still in the pillow case
A breathing mask is applied over the head of the meerkat while it is still in the pillow case

In few minutes and with the much-appreciated help of Lewis and Sky (the project field managers) we prepared the equipment to capture and anesthetize what turned out to be VLF143 (or spelled out: Female 143 of the Lazuli group). It took only a split second for Sky to close his fingers around the base of the tail of VLF143 that, without even noticing, found herself rowing with the four legs in the air before being gently put in a pillow case to be immobilized. Sky and Lewis applied a breathing mask with a mixture of Isoflurane and Oxygen over her head and in few seconds VLF143 was fast asleep. Few minutes later she was up and running again and, as if nothing happened, she resumed her activities. But this time with a collar around her neck.  In the following 13 days, thanks to the precious calls of the volunteers – our eyes on the reserve – we successfully collared additional 3 females (VEKF010, VJXF035 and VAZF027) from 3 different groups. Hopefully, by the end of this first field season, we will have collared a total of 10 females.

We are closely monitoring each collared individual to make sure that the collars do not negatively influence the animals and to collect important behavioral and ecological data. Daily observations already allowed collecting important information that will allow fine-tuning our research questions. GPS movement data automatically recorded by the collars at one-hour interval during daytime will be analyzed as a function of environmental factors (e.g. rainfall, temperature), social circumstances (e.g. number of individuals in the dispersing coalition but also their location in relation to unrelated territorial groups) and the animal’s individual state (e.g. body condition, stress level). In the long run, we aim to use information on dispersing individuals such as survival rate and reproductive success to improve already existing population dynamic models.

Close follows up are essential to record important behavioural and ecological information and to keep the animals habituated to researchers
Close follows up are essential to record important behavioural and ecological information and to keep the animals habituated to researchers

The first days of our monitoring already provided us with some very useful information. Female VJXF035 lost her sister (VJXF039) with whom she was travelling with after a car run her over. VJXF035 is now back with her group after the dominant female allowed her to rejoin. The collar that we fitted on female VAZF027 (who was dispersing alone) got found lying on the ground…without VAZF027. The collar was covered in blood and fur indicating that VAZF027 got predated, most likely by a raptor. Female VLF143 seems to have found a clever strategy to avoid spending too much time alone (the more eyes scanning around the lower the chance to be taken by a raptor of course); she has already associated, and mated, with 8 different males… I spare you the details. We hope that sooner or later she will build a somehow more stable bond with one or more males and that they will soon set off to find their own territory. Female VEKF010 seems to be the more enterprising and has already crossed the territory of two foreign groups. She has occasionally associated with a couple of males but she seems to be prioritizing a disperser’s business (the actually dispersing) to  a disperser’s pleasure (I believe it is clear what I am referring to…).

Movements of four collared females in and around Kuruman River Reserve, home to the Kalahari Meerkat Project
Movements of four collared females in and around Kuruman River Reserve, home to the Kalahari Meerkat Project

While I had to return to the foggy and miserable Zurich weather, Nino will remain in the sunny Kalahari until the end of March and will continue monitoring dispersing individuals. More info will follow soon.

Necklaces for the girls, cars for the boys – Preparations for the first meerkat field season

Cable tie and epoxy instead of diamonds

My name is MaagNino Maag, and I am about to start my PhD in the Population Ecology lab. During my study, I will investigate dispersal strategies in a wild population of the Kalahari meerkat (Suricata suricatta) in South Africa. I will use high-resolution GPS telemetry data collected from GPS radio collared dispersing female subordinates to investigate the influence of individual traits, environmental factors and social context on transition and settlement strategies. Furthermore, I will assess the survival rates of dispersing females during the stages of transition and settlement. The results of my study shall provide the complementary information on dispersal for more comprehensive spatially explicit population dynamics models and the investigation of alternative life history strategies.

Alex is applying the epoxy.
Alex is applying the epoxy.

In order to acquire movement data of the dispersing individuals, we had to prepare GPS collars. However, two days before leaving for South Africa, the GPS collars yet had to be built. For this reason we set up a workshop in our office in Zurich. On Monday afternoon, 23 September, Gabriele and I were supposed to take a plane to Johannesburg and on Saturday morning we started the workshop. Alex, engineer at CDD Ltd in Athens, followed in for the weekend to build the collars with us.

GPS collar.
GPS collar.

Since meerkats are small animals and we plan to collect detailed dispersal data in an extended area over a time period of six months, GPS collars have to meet a set of specific requirements: The weight has to be below 25 grams, the coating must be robust but should not interfere with the GPS signal, the belting can not be too edgy, and both the GPS data collection schedule and the bidirectional remote communication regime (ZigBee) should be as frequent but in the same time as economic as possible. The GPS device, VHF sender, ZigBee component, and battery were coated with epoxy. We applied cable tie as belting, which will later get covered with heat shrink to make the edges smooth. The epoxy may not be as shiny as diamonds, but the girls will still be fitted with decent solid necklaces.

After a hard weekend’s work, which lasted until Monday noon, Gabriele and I just managed to catch the plane in the afternoon.

Big cars for big boys

In the early Tuesday morning, Gabriele and I arrived in Johannesburg. I bought some airtime and data for my iPhone, Gabriele a new cell phone. After that we picked up the rental car and headed out to buy a field vehicle. Equipped with a Kia picanto and a Tomtom, everything was prepared for the day becoming a successful journey. I have to tell you though, Johannesburg is quite a big city and it took time to visit the different car dealers in the different neighborhoods, especially without a street map. Fortunately, our hosts Nancy and Greg at the Strathavon bed and breakfast were very nice and, besides offering an extra bedroom for free, provided us with a street map, which enabled us to plan next day’s car search a lot more efficient.

Two experts do the technical examination of our Toyota Hilux.
Two experts do the technical examination of our Toyota Hilux.

On Wednesday afternoon we tried our luck in Pretoria. That was a smart move as we found two nice vehicles on that day. Two good-looking Toyota Hilux 3.0 4×4, both were diesel and in good condition. Just the type of car we need! On Thursday we even found a third one. All three dealers agreed to bring their vehicle to a mechanic for full mechanical examination. Well, I had to learn that you should not trust these people too much. One changed his mind and did not bring the car at all, and the second one sold the car to someone else while we were making the technical examination. First comes, first serves! That left us with only one car, a Toyota Hilux 3.0 Diesel 4×4 KZ-TE 2004. To be honest, that was the best one anyway. What a nice car!

Our new hosts Jenny and Pat, the owners of the Sengwe Place bed and breakfast, provided us with an entire apartment. They are such friendly and welcoming people, and, besides a lot of other things, they helped us to buy insurance for the car. On Friday we will hit the road and eventually drive to the field site near Van Zylsrus, Northern Cape. Lets chase some meerkats.

Meet the Rotifer Family

IMG_1387As from Thursday onwards, we are now part of the Family of Rotiferologists. This will be the most important family to deal with in my coming PhD years. Arpat, Stefan and I were welcomed by Diego Fontaneto (Uncle Rotifer) at the ‘Istituto per lo Studio degli Ecosistemi’ in Verbania (Italy). This Institute resides in a big manor house near an idyllic lake: the perfect place to retreat to when one has to write up an article as there is no distraction besides some thorough scientific discussion (which is always welcome) and the sound of calling gulls.

The scientists at this Institute have great knowledge on aquatic ecosystems and the invertebrates that are part of such an ecosystem (for example rotifers). During the two days we visited them, they have shared their knowledge on how to resurrect resting eggs from sediment cores obtained from Lake Orta (a great place to eat an ice cream). So now we are able to bring the past back to life in our lab in Zürich.

More information on the details of my PhD project and the bizarre world of rotifers will follow relatively soon. So keep an eye on this blog if you want to know why even the NASA thinks that rotifers are rather exciting animals…

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First field season accomplished at the Alpine Marmot Project

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If this picture makes you think that it is a holiday place, it is not… This is the nature reserve of La Grande Sassière (45 ° 29′N, 6 ° 58′E), located in the Alps where I spent the last two months starting our project on alpine marmots. The field season started the 15th of May in the snow and ended on the 13th of July under the sun. Weather conditions were especially harsh this year as we worked under the snow until mid-June. I developed an experimental design to understand the physiological mechanisms that drive life history processes and, consequently, population dynamics.

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A marmot looking for some food under the snow

Hibernation plays a central role in the life history of the marmot. Overwinter survival, available fat reserves at emergence, and reproductive success the following spring are mediated by energetic expenditure during the hibernation period.  To understand the link between winter conditions and subsequent changes in demographic rates I will determine hibernation pattern changes in juveniles, yearlings and dominants.To answer this question, I worked on 45 individuals belonging to 8 different families (territories S to Z on the territory map).

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A marmot not really convinced to go into the trap

Once captured, individuals are tagged, sexed and weighed. Several biometric variables are also measured such as the total length of the marmot, the width of the front and back paws, the width of the jaw, the size of the head at the cheek bone, and the width of the pelvis. DNA samples are also taken to determine family structure. In order to recognize the socio-spatial structure of each of the family groups studied, the territory and the composition of family groups was determined by behavioral observations.

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Measurement of the tibia

To determine hibernation patterns, 33 individuals (9 juveniles, 9 yearlings, 15 dominants) have been equipped with a small logger to record their body temperature. I was really stressed until the end as pups emerged later this year than the previous years. The first one emerged the 26th of June instead of the 15th. Juveniles of two of my families emerged on the 11th of July so 2 days before the departure ;-/. Ambient temperature of the main burrow of each family is also currently recorded by loggers.

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A juvenile newly emerged

I am now back in Zürich, and I can’t wait to go back next year to retrieve the loggers and obtain exciting data from the hibernation period._IGP3188

Preliminary work at the Kalahari Meerkat Project

After an exhausting and… interesting (I believe this is the politically correct term) road trip Arpat and I finally arrived at the Kalahari Meerkat Project research station along the dry riverbed of the Kuruman River, South Africa.

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The following day, despite the lack of rest (this is what happens if you end up digging your car out of the sand at 2 am on the previous night!) we were up and running and all excited about the idea of testing our three brand new GPS radio collars for meerkats. We soon realized that the collars were too big to fit around the neck of our tiny sand-digging friends. Surely enough there is nothing that a sharp swiss army knife can’t adjust (even MacGyver had one!) and so we opened the collars, reorganized the main components (GPS unit; ZigBee for bidirectional communication with the collar and data transfer; VHF transmitter; main battery) and sealed everything back together with a generous amount of duct tape.

The next day, with the precious help of Lewis Howell who captured and safely anesthetized the animals, the collars were proudly sitting around the neck of three merkaats, which, in turn, proudly showed off their new necklace. We unfortunately experienced some issues when we tried to remotely download the data but hey, it would be too easy if things would work out fine at the first attempt no? So we did some more tests and soon the two weeks of our preliminary work got to an end. We easily removed the collars from the animals, which did not show any sign of stress or damage caused by the 25 g collars, went for a last sun downer with people working at the project and got ready for the trip back to Johannesburg. There is a saying that says errare umanum est, perseverare diabolicum, surely enough even the road trip back to Johannesburg airport was…interesting. This time we did not have to dig ourselves out of the sand we simply managed to almost miss our flight!

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We are now back in Zurich and in the process of solving the software-related problems that we experienced in the field when we tried to download the data and are looking forward to start the main part of the project.