Kalahari Trackers vs. Aircraft – The Ultimate Wildlife Counting Challenge

A team of Kalahari trackers (© Julia Burger), and an aerial survey team (© Christiaan Winterbach).

It doesn’t seem like a fair match. A couple of illiterate guys sitting on the front of a vehicle as it churns its way through Kalahari sand vs. a qualified team of experienced wildlife counters flying overhead in a fixed-wing aircraft. Whilst the first team spend hours staring fixedly at the ground whilst bumping along sandy tracks, the other team count animals directly just by looking out the window from their aerial vantage point. The challenge: who can count wildlife with the greatest precision and efficiency?

This challenge sounds a little like the incredibly uneven match-up between Russia and Spain in the recent Soccer World Cup – whoever bet on Russia taking that one? Yet one conservation researcher was crazy enough to both create the challenge between Kalahari trackers and aerial survey observers, and bet on the trackers winning the contest. Derek Keeping has good reason for his faith in the tracking team, because he knows their secret weapon. Although the guys balancing on the front of his vehicle may be illiterate when it comes to lines of ink on paper, they are among the best in world when it comes to reading animal tracks in the sand.

Let me digress. Why is the challenge of counting wildlife in the Kalahari important in the first place? The location for this particular challenge is not even inside a National Park or Game Reserve. Instead, it is a Wildlife Management Area outside the northern border of the Kgalagadi Transfrontier Park, and people still live there in a small village called Zutshwa. Whilst this area might not seem all that important to those driving through to get to one of Botswana’s renowned protected areas, conservation researchers acquainted with the region know that it is part of the Kalahari Schwelle – a critical part of the overall ecosystem (as mentioned in a previous post).

Map of the Kalahari Scwhelle and the study area chosen for the wildlife counting challenge. Situated between the Central Kalahari Game Reserve and the Kgalagadi Transfrontier Park, this region is a critical part of the Kalahari ecosystem. Map provided by Derek Keeping.

Knowing how many animals live in an area is a crucial first step in conservation, especially if some of the resident species are endangered or threatened by manmade causes. Underestimating the number and diversity of animals living in non-protected areas could lead to land-use planners deciding that an area currently designated for wildlife-related uses (including tourism) could be used for livestock instead. The scene of our wildlife-counting challenge is a Wildlife Management Area that is the traditional territory of families now settled in Zutshwa. Until recently, jobs, meat and cash for the community were generated from this Area by allowing guests to hunt some animals.

Since the nationwide ban on hunting in all forms (subsistence and commercial) on government land, the Zutshwa community have encountered some hard times. Besides no longer being able to hunt for their own meat, those who were employed as trackers in hunting safari operations are now out of a job. It is against this background that Keeping set about finding ways to employ trackers that would benefit both them and the wildlife they live with.

As Keeping points out, “Most people in Zutshwa, and other Kalahari settlements in the region, are now destitute. Being so close to the past as they are, they have remarkably positive attitudes towards wildlife and conservation compared with most rural areas of Botswana, and many of them want jobs in wildlife and tourism rather than ranching and agriculture. Unfortunately, current development policies in these remote areas favour a future of livestock husbandry.”

Wildlife counting in Botswana has relied on aerial surveys for over three decades, and the method has become the standard way to estimate wildlife numbers and trends over time. However, the cost of an aerial survey is substantial, leading the government to reduce the frequency of these surveys and focus on the northern parts of the country, where wildlife are more abundant.

Wildebeest and zebra being counted from the air. Is this the best method for monitoring wildlife populations long-term? © Christiaan Winterbach.

When asked why he thought that using trackers to count animal tracks on the ground would be preferable to observers counting animals from airplanes, Keeping explains: “There is a vast discrepancy between the numbers of observations accumulated by observers in an airplane compared to trackers on the ground. Aerial observers fatigue quickly bumping along at 170 kph in an uncomfortable airplane seat, especially when there’s not much to see in a monotonous semi-arid savanna landscape with naturally low numbers of large wildlife. By contrast, the sheer numbers of tracks that appear after a single night of animal movement in the Kalahari is astonishing. It was this observation that convinced me that an apples-to-apples comparison of aerial counts and track counts was a worthwhile pursuit.” 

From his seat at the front of the vehicle, the tracker scans the ground for spoor. All the information is then relayed to a recorder in the vehicle. © Julia Burger 2018.

The notion of using an ancient skill to conduct modern research is a romantic one, but will it produce the same quality of information as more sophisticated, expensive methods? If using trackers to count animals is merely a quaint idea that doesn’t produce reliable results, then one cannot justify such a method. So Keeping set up the ecological research version of a penalty shoot out, if you will. 

The tracking vs. aerial survey challenge was set up during the late dry season (Oct-Nov) in 2015. Both teams traversed the 6,425 sq. km area using the same straight line routes across it, covering a total of 648 km. To ensure that one method of counting animals was not influencing the other (e.g. animals being scared off by the airplane and/or the vehicle), they avoided counting the same route twice in one day wherever possible.

In the track survey, the trackers counted the tracks of anything larger than a steenbok for herbivores, and all the large carnivores (i.e. hyenas, big cats, and wild dogs). Ironically, the tracking team was actually given a handicap for this contest by limiting the tracks they recorded to the bigger animals. Trackers can easily count the tracks of animals as small as pangolins, mongoose, and African wildcat, but the aerial survey team would have no chance of seeing these species. Although good trackers can differentiate the tracks of individual animals, the statistical method used in this study simply requires them to count an animal track every time it crosses the road they are driving on.

Lions and other carnivores are almost impossible to count from the air, as illustrated by this one relaxing under a bush during the heat of the day (© Julia Burger 2018). Their tracks, however, are easily counted during a tracking survey (© Gail Potgieter).

To judge the ‘winner’ of the wildlife counting contest, Keeping and his research colleagues used a few criteria: 1) the precision of the population estimates calculated from each method; 2) the ability of each method to determine where the animals occur in the area (i.e. their distribution); and 3) the efficiency of each method in terms of the time and money spent to collect enough data for accurate population assessments.

For the population estimate test, counting by air or tracking by vehicle produced very similar results for six large grazing herbivores – gemsbok, hartebeest, wildebeest, eland, springbok and ostrich. However, the tracking team estimated more kudu than the aerial survey team. Aerial surveys in other areas of Africa consistently under-count kudu, because these browsers spend most of their time bushy habitat, which makes seeing them during aerial surveys rather difficult. Finally, only the tracking team could count enough large carnivores to make population estimates. Carnivores are rarely counted during flights, as most of them are sleeping off the night’s activities under bushes or in dens when the aerial survey team is flying overhead. The beauty of using tracks is that the sand records nocturnal animals’ activities, which are easily read by trackers the next morning.

The second test – determining animal distribution – was convincingly won by the tracking team. Where the aerial surveys showed patchy animal distributions for several herbivore species in the survey areas, the tracking survey revealed more uniform distributions. The latter result makes more sense ecologically, as animals are unlikely to occur only in certain blocks of land, when the whole area provides good habitat for them. The tracking team thus provided a more accurate picture of animal distribution for this Wildlife Management Area than the aerial survey team.

A herd of eland and a lone gemsbok are among the diverse animal species that inhabit the Kalahari Schwelle. © Julia Burger 2018.

The final test, relating to time and money, showed that whilst aerial surveys take less time (1.5 days compared to 15 days of effort for multiple tracking teams), they are more expensive. The aerial survey cost US$ 7,793.79 in total (or $12.02 per km), whereas the tracking survey cost only US$ 4,652.17 ($7.17 per km).

Keeping points out: “Vehicles are by far the most expensive component of the ground track survey, but most Kalahari trackers are also expert horsemen, and with a little logistical creativity I see no practical reason why motor vehicles would be necessary for future track surveys. Even better than horses would be camels; these desert-adapted animals have an advantage over horses, as they need less water and food, and are less likely to be attacked by lions.”

If the trackers did this survey on horses or camels, without vehicles or drivers, then the cost of the survey would be further reduced to US$ 1,399.54, or $2.16 per km. Animal-back surveys have the additional benefit of reducing the pace of the survey, allowing the trackers to record smaller, yet extremely important, species such as pangolins and black-footed cats. Pangolins are threatened by wildlife trafficking, whilst the black-footed cat is endemic to the Kalahari region, yet receives little scientific attention.

If this wildlife counting challenge were a soccer match, the score line would read 3-1 to the tracking team! Although the aerial survey produced reasonable population estimates for large, grazing herbivores (their solitary ‘goal’), the tracking survey did that and much more, at a lower cost. But the benefits of using trackers to conduct wildlife surveys do not end there. This task could be funded, and even generate income for the community, by inviting tourists to join the trackers on wildlife monitoring animal-back safaris.

This would be a unique tourism offering for wildlife-loving, adventure-seeking safari goers, whilst simultaneously helping local people realise the benefits of their own traditional tracking culture and their wildlife. With a bit of technical support from Keeping, the data collected from these surveys will be used to inform population estimates and distribution data, which can be used to highlight the importance of this part of the Kalahari ecosystem. At first it could compliment, but may eventually even replace, the increasingly cost-prohibitive aerial surveys, especially if track surveys are funded through community tourism rather than limited government budgets.

Trackers discuss some of the signs they can read in the bush.  © Julia Burger 2018.

According to Keeping, “Facilitating a new track-based wildlife monitoring programme throughout Botswana’s Kalahari that is led by expert citizen trackers would firstly yield volumes of new data and insights far in excess of what is currently attainable through the aerial survey, secondly create numerous meaningful and well-paying jobs in one of the country’s most poverty-stricken regions, and thirdly be an incentive to keep exceptional track interpretation skills – our shared intangible cultural heritage – alive in the future. Two of these three outcomes are top goals on Botswana’s national agenda, and all would enhance conservation in the long-term. I can hardly think of another single intervention that would check so many priority boxes, and do so much good.”

This tantalising idea could be a triple-win scenario, combining an authentic and unique eco- and cultural tourism experience, local sustainable development in a way that maintains traditional skillsets, and long-term wildlife monitoring and conservation. For a conservationist, the result of this wildlife counting ‘competition’ is more exciting than the Soccer World Cup!


By Gail C. Potgieter

If you are interested in making this idea a reality, please write to Derek Keeping (dkeeping@ualberta.ca) and consider a donation to the Comanis Foundation, which is a sister organisation to Tanate Wilderness that works with the community of Zutshwa to develop viable ecotourism within their Wildlife Management Area. Together they are committed to moving the vision of track-based wildlife monitoring forward in collaboration with Botswana's Department of Wildlife and National Parks, first initiating a pilot program in Zutshwa which can then be propagated to other remote communities throughout the Kalahari Schwelle.

Reference:
Keeping et al. (2018). Can trackers count free-ranging wildlife as effectively and efficiently as conventional aerial survey and distance sampling? Implications for citizen science in the Kalahari, Botswana. Biological Conservation 223:156-169.