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

Amphibian Conservation Research Symposium

Last week, I headed off to the University of Canterbury in the UK to present at the Amphibian Conservation Research Symposium. This is the fourth year that I’ve attended this meeting ,which aims to bring together researchers from all around the world working on all facets of amphibian conservation.

 

 

 

The attendees in Canterbury
Photo credit: @AmphibianCon

 

For me, the meeting is always one of the major highlights of the year; an opportunity to get out of the office and network with a crowd of incredibly diverse people united with an infectious passion for amphibian conservation. As I’m in the final months of my PhD (and am therefore chained to my computer frantically writing up my thesis) this year was particularly rejuvenating- giving me a chance to live vicariously through the experiences shared by my fellow attendees. I may not have the time to do any fieldwork this year, but hearing about people scuba diving to discover the breeding ecology of critically endangered frogs, or using drones to survey bromeliads for cryptic amphibian species, cannot fail to inspire.

 

 

Undoubtedly a new life-goal for me: Arturo Muñoz Saravia surveying breeding behaviour of the Titicaca Water Frog through high-altitude scuba diving
Photo credit: @TetZoo

 

ACRS always aims for a very broad mixture of talks, and this year was no exception. Topics spanned research into animal husbandry, infectious diseases (always necessarily a major topic in amphibian research, sadly), monitoring for cryptic species, and species’ reintroductions, to name just a few. These were complemented by a great set of keynote speakers. This year the key message I took from these talks is just how large and co-ordinated the amphibian conservation community is. Keynote talks from Anne Baker and Phil Bishop reminded me that although applied conservation often seems like working in a small-scale bubble, there is a whole alphabet soup of organisations (ASA, AArc, IUCN SSC ASG….the list is as endless as it is bewildering) co-ordinating across the globe to improve the fate of amphibians.

 

 

 

Penultimate talk of the conference: when can we rely on analysis of amphibian count data?
Photo credit: @AmphibianCon

One great aspect of ACRS is their Future Leaders programme: each year, the committee funds the attendance costs of several early-career researchers who have made substantial achievements in amphibian conservation in their host country. This years’ leaders hailed from Nepal, Brazil, India and South Africa, and each gave great presentations and insight into working in countries where things operate very differently to Europe! Particularly notable was Sethu Parvathy’s impressive and hilarious one-woman theatre performance of the persecution of frogs in cardamom farms in India (simultaneously from the perspective of farmers, frogs and rats), and the inspirational work of Luis Marin da Fonte. His involvement in discovering the only known population of a species new to science (the aptly named Admirable Red-belly toad) and securing protection of this site by successfully campaigning against the building of a hydroelectric plant upstream from the population, drew a spontaneous round of applause from the audience.

 

 

 

ACRS Future Leaders; Biraj Shretha, Luis Marin da Fonte, Sethu Parvathy and Fortunate Phaka
Photo credit: @AmphibianCon

 

My contribution to the meeting was a talk warning of the pitfalls of analysing count data; as the penultimate speaker on the last day of the conference, giving a talk on population modelling to a tired audience seemed like an uphill battle. However, I was happy to be approached by several people after the talk who were interested in my solution to the issues of non-closure in count data, and I hope that some fruitful collaborations will result from the meeting.

 

The inspirational story of the Admirable Red-belly toad
Photo credit: @AgentAmphibian

 

 

Thanks to the organisers at the University of Canterbury for organising another great conference! And also to Darren Naish of Tetrapod Zoology for writing up this great summary of the conference.

 

Shrinking whales and warning signals

As with, I suspect, an embarrassingly high number of scientific papers this one was conceived over a mug of something warm and caffeinated, but unlike most of my other publications I finally have something charismatic to talk about!

 

Whales are big news (pun intended), and the commercial hunting of whales is a sensitive and emotive topic, with what could probably be described as a collective embarrassment regarding the mass slaughter carried out during the 20th centaury, and subsequent collapse of global whale populations. However a by-product of this generally frowned upon practice – and some frankly anally retentive bookkeeping – is an exceptional and unique record of the whales caught during this period. The International Whaling Commission required a record of all whales hunted, the approximate location of their capture, as well as details on their size to be noted down. The net result is a staggering record of over 2.8 million individual whales harvested from 1900 onwards.

Now the reason I know all of that is because of that caffeinated beverage in a small café in Hobart, during a visit to the University of Tasmania’s Institute of Marine and Antarctic Research. The idea behind the visit was to test the effectiveness of a method for predicting population declines that incorporated classic abundance based early warning signals1,2 along side shifts in trait dynamics3 on data from real-world population collapses. Our original intention was to simulate population collapses due to overharvesting and look for early warning signals (EWSs) before the collapses occurred. However one of the key aims of EWSs is to make them applicable to species of conservation interest, and whilst brainstorming the best way to approach this we realized that data might already exist which would allow us to test these methods – data that describe the dynamics of populations prior to documented collapses, that include information on the body size of individuals. And thus this Nature Ecology & Evolution paper was born – where we identify both abundance based and trait-based EWSs up to 40 years prior to the collapse of whale populations.

For me a few really interesting secondary results came out of this. The first was the sheer scale of the whaling effort during the 20th centaury – at its peak over 30,000 Blue whales were removed in a single year, with similar peaks seen in the other three species we looked at. So perhaps it shouldn’t have been as surprising as it was to see dramatic changes in the body size of these whale populations – a decline of over 4m in Sperm whales caught over a 80 year period. What is fascinating to me is the interaction between the ecology of each species and the techniques developed to hunt whales, and how this impacts the trend in body size over time; Sperm whales decline in size consistently through time, probably because they are relatively slow moving, where as for faster species landed body sizes initially increase (in line with technological advancement4) and then decline as all the large individuals are removed.

This paper felt in many ways cathartic – that we can use this data from a barbaric period of commercial excess to develop and test methods that might be applied to the current diversity crisis feels good. And whilst we are still a long way from making perfect predictions about the fate of biodiversity in the Anthropocene, every step towards this goal helps.

The paper in Nature Ecology & Evolution is here:

http://go.nature.com/2skjWUY

 

This paper was made possible by a Swiss National Science Foundation International Short visits grant, and an ERC Starting grant (#337785) to A.O

 

References

  1. Dakos, V. et al. Methods for detecting early warnings of critical transitions in time series illustrated using simulated ecological data. PLoS One 7, e41010 (2012).
  2. Scheffer, M. et al. Early-warning signals for critical transitions. Nature 461, 53–9 (2009).
  3. Clements, C. F. & Ozgul, A. Including trait-based early warning signals helps predict population collapse. Nat. Commun. 7, 10984 (2016).
  4. Basberg, B. L. Technological change in the Norwegian whaling industry. Res. Policy 11, 163–171 (1982).

 

Movement Ecology Summer School – August 2017

It is our pleasure to announce the 2017 Movement Ecology Summer School (MESS) organised through the Life Science Zurich Graduate School, PhD Ecology Program. The MESS will be held in Faido (Ticino, Switzerland) during 27.8 – 1.9.2017.
The course builds on the expertise and positive feed-backs of the past summer schools. For this year too, we were able to secure the participation of leading scientists in the field of movement ecology and remote sensing:
Dr. Gabriela Schaepman-Strub (Zurich University)
Prof. John Fieberg (University of Minnesota)
Prof. Luca Börger (Swansea University)
Dr. Gabriele Cozzi (Zurich University)
 
This one-week course covers several aspects of animal movement ecology and includes both theoretical and conceptual and practical sessions. The course builds on analytical complexity and leads the participant through several steps. During day one, the participants will learn to source landscape information through available remote sensing imagery and to import, manipulate and represent geographical data into R. Day two will be dedicated to the decomposition of movement trajectories and characterisation of movement modes and phases. During day three the participants will be exposed to common methods used in the calculation of home ranges and discuss the pros and cons. During the next day we will use presence/absence data to analyze habitat selection. Finally, during the last day, the participants will be exposed to some new tools and methodologies to include data from alternative sensors (e.g. accelerometers) in the study of animal movements. Fundamental aspects such as study design, spatial autocorrelation, sources of error and time varying covariates will be discussed. Data sets will be provided but the participants are encouraged to bring their own data. Active participation during the course is required to obtain 2 ECTS credit points.
 
Please note, this course is organised for PhD students of the Life Science Zurich Graduate School. Priority will be given to students registered in the PhD Program in Ecology, however PhD and MSc students from other universities may attend if there are available places. 
 
Please do not hesitate to contact me (gabriele.cozzi@uzh.ch) for further information

Where can the wild things roam? Combining ecological suitability and human acceptance for the Swiss wolf.

About one third of the Swiss landscape offers suitable wolf habitat. Nonetheless, there is only a small fraction thereof where the wolf is tolerated by local communities. Those regions – characterized by both favourable environmental conditions and a positive attitude towards the wolf – are identified as candidate regions for the successful short to medium-term wolf expansion, according to a study conducted by the population ecology research group at the University of Zurich

©RamiroMarquezPhotos / iStock

The wolf was eradicated in Switzerland and from large parts of continental Europe including France and Germany by the end of the 19th century. Following legal protection, the wolf population started naturally increasing and expanding, and in 1995 its presence was confirmed in Switzerland. Sightings have increased since. Despite 13’800 km2 of Switzerland are characterized by favourable conditions such as large forests with little human pressure and have thus been identified as suitable wolf habitat, wolf expansion in Switzerland has been substantially slower than in other parts of continental Europe. As the wolf is more and more subject to human-dominated landscapes, scientist at the University of Zurich developed a novel method that integrated both ecological and human components to identify regions with favourable environmental conditions and where the wolf was tolerated.

Mapping human acceptance of the wolf to identify suitable socio-ecological areas

socio-ecological suitability model
Combining human acceptance (a, c) and habitat suitability (b, d)
helps identifying socio-ecologically suitable wolf habitats in Switzerland (e).

About one third of 10,000 randomly selected residents in Switzerland participated in the survey. Combining the response from questionnaires with geographical information, Dominik Behr and his team created a nationwide map of human acceptance. Acceptance decreased with increasing altitude of residency and even more so where high numbers of sheep and goats were held. Acceptance increased with increasing distance from confirmed wolf presence and in densely populated areas. People who perceived the wolf as dangerous to humans and harmful to livestock and wildlife mainly opposed the wolf. Younger people, and people who believe that the wolf had a positive influence on the ecosystem had a more positive attitude towards the predator.

“When we overlapped our human acceptance map with a habitat suitability map for the wolf, we realized that only about 6% of Switzerland was characterized by both a positive attitude and favourable environment conditions. This was in contrast to results from the habitat suitability map, which returned one third of the Swiss landscape as being suitable for the wolf” said Dominik Behr. “As wildlife biologists, we are good at understanding the ecological factors determining the suitability of a habitat for a wildlife species. Due to ever-increasing overlap between human and wildlife, however, we are obliged to take into consideration how human acceptance modifies our ecological description of habitat suitability. This study demonstrates one effective way to do this.” stressed Arpat Ozgul, professor of population ecology at the Department of Evolutionary Biology and Environmental Studies at the University of Zurich, and co-author of the study.

A novel framework to manage wolves and people
The socio-ecological map created by Dominik Behr and his co-authors appears to accurately represent the wolf situation in Switzerland of the past years, including identifications of areas of high, moderate or limited conflict. “By capturing areas characterized by both favourable environmental conditions and a positive acceptance towards the wolf, our approach is a valuable tool to identify overall socio-ecological suitable areas for the wolf. Under given conditions, those regions are good candidates for the successful short to medium-term expansion of the wolf. Additionally, this approach allows to identify key regions where proactive and targeted socio-ecological management plans and a constructive dialog among different stakeholders are needed” said Dr. Gabriele Cozzi, who coordinated the study.

Special thanks go to the 3142 people that returned the completed questionnaire – this study would not have been possible without their contribution.

Behr DM, Ozgul A, Cozzi G (2017) Combining human attitude and habitat suitability: a unified socio-ecological suitability model for the wolf in Switzerland. Journal of Applied Ecology

BUSS 2016

written by Megan

My name is Megan, and I was an intern in this lab over the summer in the Biology Undergraduate Summer School, or BUSS program. That’s a very simple way of summing up all the amazing experiences I had thanks to the program and my host lab, and I think it would be best to start this blog post by talking about the BUSS program itself.

The BUSS program aims to unite students from all over the world with varying levels of experience in different biological fields to teach them new and exciting things. It was inspirational to witness the kind of devotion amongst all the people I had the pleasure to meet. The program allowed me to learn about topics from various fields, especially those outside of what I was used to. Seminars, retreats, and interactions with some of the top researchers reminded me of why I enjoy science so much. I was guided through by these amazing mentors as well as my peers who attended the program with me and the two months went by very quickly.

 
Zürich in summer (photos taken by Megan)

I worked with Koen van Benthem in theoretical biology on modelling techniques and gained new skills in different programming languages, practiced giving scientific presentations, and even learned to LaTex. My project itself was working on increasing the biological significance of Inverse Integral Projection models which use maximum likelihood to estimate parameters such as survival and growth within populations. As always, it was difficult to get started on a new project, but my host lab was very supportive. I learned many techniques and got to discover what theoreticians do. I also got to hear about all the things the other members of the lab do; and they’re all truly extraordinary people who really care about their work. Perhaps most importantly, it was very obvious to me that this lab works well as a unit. There was so much friendship and it was a wonderful environment; that’s an extremely important thing when you’re learning.

Altogether it was an extraordinary experience, and thank you to all who allowed me to come here and took the time to make feel so welcome.

 

Click the BUSS logo for more information on the program

Grimm’s enchanted forest – Gabriele about his work on bears and wolves

As researchers and conservationists, a key component of our work is to make our research findings accessible to everybody and engage with the general public. This is particularly important for sensitive and ‘political’ topics such as the recolonisation of the Swiss territory by large carnivores.

Gabriele talks to adults and children about his work on bears in Turkey and wolves in Switzerland, as part of the Grimm’s special exhibition organised by the Zürich Zoological Museum. If you are keen to learn more and talk to Gabriele, do not miss the next opportunity on Sunday 29th January 2017 at 11:30 in the museum main building.

 

Triple congratulations to Dominik

Series of congratulations to Dominik on three wonderful achievements!

First and foremost, he managed to persuade a wonderful lady, Regula, to tie the knot. We wish them a long and happy life together. May they grow old on one pillow!

regula&dominik

Secondly, he successfully attracted third-party funding to support his PhD study on wild dog dispersal in Botswana, and started his PhD work. He is currently out and about, gps-collaring wild dogs together with Gabriele.

Last but not the least, he just received the Albert Heim Foundation’s 2016 Science Award, with his MSc work on the Swiss wolves. This award is given annually to outstanding work by young researchers in Swiss universities. The broad spectrum of research includes various disciplines around canines, including interdisciplinary issues such as the human-wolf relationships, which Dominik has nicely studies during his MSc. He sure will be a promising contender again with his new canine sp. in the upcoming years.