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The effective range of radio telemetry
in rain forest habitat is only about 50 yards, yet tigers
may roam 6 or more miles in a single day.
As a result, field biologists use camera traps to study
tigers in dense forests where radio telemetry is not practical.
During 5 years of camera trapping in Way Kambas National
Park, in Sumatra, Indonesia, 46 individual tigers were identified
using this system.
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Camera trap
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Satellite image
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- Field biologists start with a detailed forest
map, or better yet, a recent satellite image of an area to decide
the best sites to place the cameras.
- A field reconnaissance confirms that the trails
are negotiable, where trails need to be cut, and where good
sites for camera placement are. These trails are plotted on
the map.
- About 20 camera traps are set-up along the
trails, and the locations of the cameras are marked on the map.
- Each camera is equipped with an infrared beam.
When an animal walks the trail, it breaks the beam, triggering
an automatic focus, flash, and film advancing mechanism to take
a photo and record date and time.
- Film is changed every several weeks and batteries
monthly. In the Way Kambas site, field teams walked a circuit
of about 50 miles, camping out for three days to service the
cameras and record sign of tigers and their prey.
- As the archive of photographs increased, staff
assembled a tiger mugbook in the tiger community through stripe
identification.
- In the following months, the tigers were named
and the locations at which they were photographed plotted on
the map.
- Each tiger's home range can be determined by
connecting the localities.
All photographs and maps courtesy of PHKA & WWF Indonesia
program
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