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Tagged wildebeest alerts park rangers The movements of hoofed mammals give away the presence of poachers – who are not targeting them but elephants or rhinos. This was demonstrated by a trial with tagged hoofed animals. Park rangers are alerted and can intervene in time. TEXT ANNE VAN KESSEL PHOTO GETTY
NATURE MANAGEMENT AND TECHNOLOGY
T
he ivory trade ensured the extermina- battle too. A few years ago, British research- how quickly rhinos react to their attackers.
tion of 90 per cent of the African ers came up with the idea of implanting Rhinos and elephants are rarely predated by
elephant population over the past sensors under the skins of rhinos and hid- other animals and are therefore not particu-
century. And even now, about 55 African ing tiny cameras in their horns. The idea larly alert to danger.
elephants are killed every day, although was that if anyone came too close to one of This idea led Wageningen researchers in
rhinos and elephants appear to have bene- the animals, its heartbeat would speed up the Wildlife Ecology and Conservation chair
fitted from the lockdowns. In 2019, 594 and the park rangers would receive a signal group to think up a different plan. Prey ani-
rhinos were killed in South Africa; in 2020, to go and find it. If they got there too late, mals such as zebras and wildebeest do react
394 were killed. But game park managers the camera would have snapped the poach- quickly to disturbances and threats such as
fear for an increase after the pandemic. er. A nice plan, but dangerous too, because lions. They probably react to poachers as
In December, when the lockdown was what if the poachers hack and read the sen- well, even though they are not targeted by
briefly lifted, experts from the South sors? Then science will help them instead them. So could zebras and wildebeest serve
African parks saw an immediate increase of the rhino. And there’s the question of as informers? >
in poaching.
The main poaching zone in South Africa is
the Kruger Park: a game park on the bor-
der with Mozambique that covers an area
the size of half the Netherlands. For a few
years, heavily armed park rangers have been
patrolling the park together with the army.
‘If an animal suddenly starts
This leads to regular and sometimes deadly
clashes with the poachers.
running in hot weather, there
must be something going on’
SENSOR UNDER THE SKIN
Scientists have got involved in the escalating
To figure that out, ecologist Henjo de Knegt De Knegt. ‘When they saw an animal, they ty and to increase or limit populations,’ says
and his colleagues set off for South Africa in anaesthetized it with a dart and sent the co- De Knegt. Some animals were transferred
2019 with a Dutch Research Council (NWO) ordinates to their colleagues on the ground, to Welgevonden from other parks, and the
grant. In the Welgevonden game reserve in who drove there as fast as they could and put researchers made grateful use of them. ‘It
the north-east of the country, they fitted 138 the collar on.’ was relatively easy to fit these animals with a
zebras, impalas, wildebeest and elands with A lot of the animals in the study had come transmitter when they arrived at the park.’
a collar carrying a GPS, an accelerometer from other parks. ‘In Africa, parks exchange All the animals were brought to a fenced-off
and a thermometer. ‘If an animal suddenly animals in order to maintain genetic diversi- section of the park, to restrict the research
starts running in hot weather, there must be area. There the researchers and the park
something going on,’ says De Knegt. staff simulated disturbances, imitating
The data from the transmitters goes first to tourists, for instance, who were exploring
a mast with a receiver, and from there to a the park by car or on foot. ‘In other experi-
data centre in Europe via a 3G or 4G internet
link. The researchers in Wageningen re-
‘We ask the park ments, we asked the park rangers from the
anti-poaching unit to act like poachers. They
ceive, decode, and analyse the data using an
algorithm developed in Wageningen.
rangers to act know how to move through the bush with-
out being noticed.’
Fitting the animals with the transmitters
was a big job. ‘Team members flew over the
like poachers’ To motivate the park rangers to do their very
best not to be spotted, they were told to look
park in a helicopter with a vet to do it,’ says for a wildebeest with a red spot on its back.
PHOTOS JULIA SCHÄFER
Impalas, zebras and eland antelopes get transmitters in Welgevonden game park in South Africa.
24 WAGENINGENWORLD | 2 | 2021NATURE MANAGEMENT AND TECHNOLOGY
Whoever found it could shoot it and eat the the animals’ necks manually, but you also
meat. ‘At least, that was what the park man- need receiver stations. These kinds of game
agers told the park rangers. In fact, there ‘There will be reserves don’t have electricity, so you need
was no such marked animal.’ solar panels and batteries.’
During one of the first experiments, De a stronger What is more, the masts with the receiver
Knegt’s colleague Jasper Eikelboom pre- stations must be strong enough to with-
tended to be a tourist. Back in Wageningen, response to a stand a knock from an elephant. ‘Our tech-
De Knegt looked at the data coming in from nical partners MTM and IBM installed the
the animals’ collars. ‘After the trip, Jasper human than masts and antennae for us. In future, the
was a bit disappointed that he hadn’t seen parks will have to organize that themselves.’
any game. From the data I could see that to a lion’ The transmitters used in this study lasted a
there was game near him, but that the ani- year, but new sensors with solar cells could
mals fled before he had seen them.’ be operational for several years or even the
With the algorithm, the computer could animal’s whole life.
detect 86 of the 100 simulated disturbances, distinguish between the way a zebra reacts
as we can read in the article published in to a lion and to a poacher. De Knegt thinks CREATING SAFE HAVENS
Nature Scientific Reports. The algorithm as- it can. ‘The more unpredictable something Not every park can afford such a system.
sessed whether the tagged animals behave is for an animal, the stronger its reaction. A ‘There are parks in Africa where the man-
abnormally. To establish what their normal lion is not entirely unpredictable: zebras and agers don’t even have enough money to buy
behaviour was, the animals were allowed lions have evolved together and have lived shoes for all the park rangers,’ explains De
to roam around with the collars on for 11 side by side for a long time. But they don’t Knegt. So there’s a big chance of poachers
months, which generated a huge mountain meet so many humans so an encounter with shifting their operations to parks without
of data. humans will prompt a stronger response.’ transmitters. The ecologist comments on
It was apparent from the experiments that A new experiment – which has been delayed this: ‘Even if that is the case, you are still cre-
animals sound the alarm when tourists or by the pandemic – should show whether De ating safe havens where the animals can live
poachers come within about 500 metres of Knegt is right about this. ‘In a Kenyan park undisturbed and where you can maintain the
them. De Knegt: ‘The animals are already we are going to tag not just prey animals but genetic diversity.’
reacting before the people can see them.’ also lions and hyenas.’ But he makes no claim that the sensors pro-
The concept has already been proven to vide a one-stop solution to the problem of
work, according to De Knegt. But the system HACKED poaching. ‘Poaching is a multifaceted prob-
is not yet ready for use. In nine per cent of The technique offers several advantages over lem, which you’ve got to tackle on several
cases, the computer sounded the alarm un- the sensors used on rhinos and elephants. fronts at once. I hope we have a contribution
necessarily. And in Welgevonden, there are ‘If this system gets hacked, the poachers to make because we don’t target the poacher
no large predators such as lions, although don’t gain anything from the data. They directly.’ He is referring to techniques such
other big cats are found there now and then. know where the prey animals are and where as drones and fences with sensors, which
De Knegt: ‘Leopards occasionally come into they are themselves,’ laughs De Knegt. ‘Also, do target the poachers themselves. ‘Such
the park, hunting antelopes and impalas. it is easier to tag the prey animals and they techniques often offer advantages for a few
You can’t keep them out with fences.’ are often present in larger numbers than weeks, but you always get into an arms race
elephants and rhinos. This makes it possi- with the poachers. They think of an answer
IMPALA UP A TREE ble for us to observe changes in behaviour like a heat-resistant suit or camouflage
The experiments back this up. ‘At one point earlier.’ clothing or just switching off the sensors
I saw that the signal of one of the impalas Both techniques have the advantage that on the fence. And then you need to come
stayed at one spot.’ That could mean one of park rangers can head straight for the crim- up with something new.’ De Knegt hopes
two things: either the impala was dead, or inals. ‘This will mean fewer chance encoun- the Wageningen solution will last for a
its collar had come off. ‘I sent Jasper to look. ters that can lead to an exchange of fire.’ long time. ‘How can a poacher arm himself
He found the impala hanging in a tree. A But there are disadvantages too, such as against herds of smart animals?’ W
leopard must have done that.’ the costs. De Knegt: ‘Not only do you need
The question is whether the system can transmitters that have to be put around www.wur.eu/innovative-nature-conservation
WAGENINGENWORLD | 2 | 2021 25You can also read
