As human populations grow, habitat loss threatens many creatures. Mapping wildlife habitat using satellites is a rapidly expanding area of ecology, and NASA satellites play a crucial role in these efforts. Tigers, jaguars, and elephants are a few of the vulnerable animals whose habitats NASA is helping track from space.
“Satellites observe vast areas of
Earth's surface on daily to weekly schedules,” said Keith Gaddis, ecological
conservation program manager at NASA Headquarters in Washington. “That helps
scientists monitor habitats that would be logistically challenging and
time-consuming to survey from the ground — crucial for animals like tigers that
roam large territories.”
Here’s how NASA and its partners
help protect three of Earth’s most iconic species:
Trouble (and
Hope) for Tigers
Tigers have lost at least 93% of
their historical range, which once spanned Eurasia. Roughly 3,700 to 5,500 wild
tigers remain, up from an estimated low of 3,200 in 2010.
In a recent study, researchers
reviewed over 500 studies that contained data on tigers and their habitat
across Asia. The team found that the area where the big cats are known to live
declined 11%, from about 396,000 square miles in 2001 to about 352,000 square
miles in 2020.
Led by the Wildlife Conservation
Society (WCS) and funded by NASA’s Ecological Conservation program, the team
developed a tool that uses Google Earth Engine and NASA Earth observations to
monitor changes in tiger habitat. The goal: aid conservation efforts in
near-real time, using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) imagers, and Landsat satellites.
The researchers mapped large
stretches of “empty forests” without recent tiger presence. Because these areas
were suitable habitat and are still big enough to support tigers, they are
potential landscapes for restoration, assuming there is enough food. If tigers
could reach those areas, either through natural dispersal or active
reintroduction, it could “increase the land base for tigers by 50%,” the
scientists reported.
“There’s still a lot more room for
tigers in the world than even tiger experts thought,” said lead author Eric
Sanderson, formerly a senior conservation ecologist at WCS and now vice
president of urban conservation at the New York Botanical Garden. “We were only
able to figure that out because we brought together all of this data from NASA
and integrated it with information from the field.”
Where the Jaguars Are
Jaguars once roamed from the U.S.
Southwest to Argentina. But in the past century, they have lost about 50% of
their range, according to the International Union for Conservation of Nature
(IUCN). Like tigers, jaguars must contend with poaching and the loss of food
sources. Wild jaguars number between 64,000 and 173,000 individuals, and IUCN
classifies them as near-threatened.
In Gran Chaco, South America’s
second largest woodland, jaguars and other animals live in an especially
threatened ecosystem. The dry lowland forest stretches from northern Argentina
into Bolivia, Paraguay, and Brazil, and has experienced severe deforestation.
BEFORE AND AFTER
Gran Chaco Deforestation
Dec, 2000 – Dec, 2019
These MODIS images show deforestation that occurred in Argentina’s Salta
Province, which composes part of the Gran Chaco, between December 2000 (first
image) and December 2019 (second).
Jaguars in Argentina’s Chaco may
number in the hundreds. Using data on land use and infrastructure, plus Earth
observations from MODIS and Landsat, NASA-funded researchers mapped priority conservation areas for jaguars and other important animals. About 36% of the
priority areas in Argentina’s Chaco are currently “low-protection” zones, where
deforestation is allowed.
“Managers and conservationists
could use the new spatial information to see where current forest zoning is
protecting key animals, and where it may need re-evaluation,” said lead author
Sebastian Martinuzzi of the University of Wisconsin–Madison.
Elephants Seek Out Forest Havens
African savanna elephants now
occupy an estimated 15% of their historical range, and their numbers have
declined. One study surveyed about 90% of the elephants’ range and estimated
that their numbers dropped by 144,000 elephants from 2007 to 2014, leaving approximately 352,000
individuals. In 2021, the IUCN updated the elephants’ status to endangered.
A recent study used NASA
satellite-derived vegetation indices and other data to study elephants in
Kenya’s Maasai Mara National Reserve, and in nearby semi-protected and
unprotected zones. Researchers found that, especially in the unprotected areas,
the elephants preferred dense canopy forest, particularly along streams, and avoided open areas
like grasslands, especially when more people are present. Human development,
such as tourism lodges, is often built in such forests.
Prioritizing elephants’ access to
forests in unprotected areas should be of utmost importance for land managers,
the researchers said. Because the elephants avoided grasslands, some of those
areas could be used for development or livestock — balancing need for economic
development and elephant habitat.
The IUCN likewise classifies Asian
elephants as endangered. In southern Bhutan, crop depredation and wildlife approaching human
settlements is escalating conflicts between people and elephants. In 2020–2021,
Bhutanese scholars studying in the United States were selected to participate
in the NASA Capacity Building Program’s DEVELOP program. Partnering with the Bhutan Foundation, Bhutan Tiger
Center, and Bhutan Ecological Society, the teams used NASA Earth observations, elephant
occurrence data, and other information to model current habitat suitability and
map wildlife pathways between habitats, aiding strategies that reduce the risk
of conflict.
By Emily DeMarco
NASA’s Earth Science Division, Headquarters
Source: NASA Is Helping Protect Tigers, Jaguars, and Elephants. Here’s How. - NASA Science
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