NAIROBI — At the Balule Nature Reserve in South Africa, rangers were using decades-old maps to track down poachers. They patrolled the entire 155-square-mile reserve — with limited success.
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Then in 2014, the reserve recruited consultant Tom Snitch, who brought in satellite imagery of the park — outlining features such as game trails and watering holes. It was the first time these rangers saw an overhead view of the park they patrol every day.
The rangers stuck colored pins onto the map to mark the spots where they had found a dead elephant, rhino, or lion. They identified clusters of pins — all within about 520 feet of a couple roads outside the reserve. It became clear the poachers were driving on the road outside the park’s fence, looking in to spot the animals. They would then wait until nightfall, hop the fence, and kill the animals.
In response, the reserve instructed its rangers to focus on patrolling the road. When they found animals within 520 feet of the road at the end of the day, they would try to encourage them back into the bush.
“Almost immediately, the poaching stopped,” Snitch said. “This was not a great intellectual leap of mathematics. ... What they needed to do is use satellite imagery to reduce the amount of space they needed to cover.”
This is just one of the ways that satellites are being used to support conservation efforts on the African continent. Beyond poaching, space technology can also be used to identify deforestation and grassland degradation, as well as to better inform wildfire management — helping to protect wildlife and the communities that depend on these animals for tourism revenue and to support their livelihoods.
Habitat loss is the leading threat to wildlife in Africa, as agriculture, infrastructure projects, and resource extraction jeopardize habitats and animal migration corridors. It is also the main threat to 85% of endangered or threatened species globally.
Conservation efforts and supporting livelihoods
Kenya is a popular destination for nature-based tourism, which helps employ communities and fund conservation efforts.
"Wildlife is important to Kenya and the Kenyan economy — it's very, very critical in terms of driving Kenya's economy and improving people's livelihoods," said Yussuf Wato, wildlife expert for WWF Kenya.
But in addition to the threat of poaching, the country’s wildlife is facing habitat loss and degradation, among other significant challenges, as the growing population of humans competes for the same land and resources.
“Most of the species that we are managing are reducing in numbers,” Wato said.
In 2015, the World Wide Fund for Nature and its partners started putting GPS satellite tracking devices on elephants in Kenya to help understand their behaviors and prevent poaching. Currently, 10 elephants are collared in the country, and the organization is doing the same in Cameroon, Gabon, and Tanzania.
The collars allow WWF to identify elephants’ locations and the park to allocate more rangers to those areas. Alerts can also be issued when elephants are killed or approach communities — helping rangers prevent retaliatory killings if the animals destroy property or hurt people.
“The conservation of our environment ... is critical to national development, enhancing human well-being, and sustaining the country’s economy.”— Jean Kapata, Zambian minister of lands and natural resources
By identifying where elephants spend their time, researchers can determine landscape highlights — such as water or certain plants — that draw in the animals. Local officials can use this data to select areas for land reserves, helping retain biodiversity and conserve the elephants’ habitat.
WWF also works with communities in areas that are frequented by elephants to put up fences around their crops, grow plants the animals do not like to eat, and set up beekeeping operations, helping to keep the elephants away.
But the collaring process is not easy. It is a huge, expensive operation, requiring a helicopter to sedate the animal from above and a veterinarian to assist. One collar alone can cost up to $10,000, but together with the collaring process and monitoring for the item’s three-year life span, this can reach up to $30,000, Wato said.
WWF is now partnering with Wageningen University in the Netherlands and the Kenya Wildlife Service on a project for collaring antelopes to better understand how the animals react when poachers are nearby. The antelopes could act as a harbinger, alerting to the presence of poachers, so that conservationists do not have to collar endangered species.
A park in South Africa has also provided rangers with GPS tracking devices so they can document signs of poachers — footprints, cigarettes, and cloth tied to fences — while they are patrolling, Snitch said. This can then be used to identify where the poachers are frequenting.
Deforestation and grassland degradation
In Tanzania, The Nature Conservancy, or TNC, is monitoring forest loss in the Greater Mahale ecosystem and Lake Tanganyika water basin with satellite imagery, comparing it with historical photos. This information is verified on the ground, helping identify the drivers of forest loss. Communities are then consulted on forest management plans, according to Anne Trainor, remote-sensing expert at TNC.
It found that the forest cover loss in the Lake Tanganyika basin declined about 26% over the past three decades, and forest loss in the Greater Mahale ecosystem declined about 10% during that time, according to a 2018 report from TNC. East Africa is estimated to have lost nearly 15 million acres of forest between 2000 and 2012 for reasons including timber harvesting and agriculture. These forests absorb carbon and play a key role in preventing climate change.
In collaboration with the University of York, TNC also uses satellite imagery in Tanzania to identify grassland degradation, which has a negative impact on wildlife populations and pastoralist communities that the ecosystem supports. The imagery helps identify invasive species that can make the land not grazeable for livestock and can crowd out biodiversity. When livestock does not have access to adequate grassland, the income of pastoralist communities can be harmed.
Between 2015 and 2018, TNC used satellite imagery to map the entire country of Zambia, in partnership with the government, to identify where animals such as giraffes and hippos congregate and create a species distribution model. Satellite imagery was overlaid with aerial surveys from planes to identify the animals.
This assists in understanding the environmental features that these animals are drawn to and predicting areas where they are likely to go. Jean Kapata, Zambia's minister of lands and natural resources, said in a report on the project that the government would use the map to identify areas that are critical to conserve and to evaluate future development plans, within the context of the need to protect these areas.
“The conservation of our environment and its natural resources is critical to national development, enhancing human well-being, and sustaining the country’s economy while maintaining ecosystem integrity and resilience,” she wrote.
Using data from MODIS — an instrument that sits on a satellite with a tool to detect temperature change — TNC has also worked in the country’s Kafue National Park, one of the largest parks in Africa, to better understand the ways that the forest burns and the routes it takes while burning. According to McRee Anderson, director of the interior highland and fire program at TNC, this informs strategies around early, controlled burning, which helps prevent widespread, uncontrollable fires that can damage the park’s biodiversity and the animals’ habitat.
Satellite data is becoming simpler to use and more accessible for the conservation community, TNC’s Trainor said.
One tool making this easier is Google Earth Engine, a cloud-based platform for satellite imagery and geospatial datasets with analysis capabilities. Through this platform, it is possible to write computer code to calculate vegetation from satellite data, among other tasks. The data is then processed in the cloud.
A decade ago, before the platform was launched, much of this data had to be downloaded and processed on a personal computer with proprietary software, meaning someone would need software and an expensive computer with high levels of computing capacity.
“It's made remote sensing in the conservation world so much easier because you don't need these huge machines,” Trainor said, adding that now freely available and accessible remote-sensing datasets such as Landsat, MODIS, and Sentinel are increasingly being used in the conservation world.
Even so, there is still a relatively steep learning curve to interpret this data. But there are more training resources available to build capacity, such as online courses.
“Every remote-sensing map is a model, and models are an estimation of reality. They are not actual reality,” Trainor said. “Every map has assumptions to them. They're very powerful, as long as those assumptions are understood.”
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