A project to count the extremely rare Bengal tiger has begun in India, using special computer programmes and radio tracking collars for the first time.
Experts will be searching the Sunderbans, a forest which crosses the border between India and Bangladesh.
The computer programme should stop the tigers being counted twice, making this the most accurate survey yet.
It's thought there are around 3,500 Bengal tigers left in the wild, compared to about 100,000 in 1900.
Conservation groups have criticised India in the past for not doing enough to help the Bengal tiger.
Tigers are often counted by using their footprints, also called pugmarks.
It's hoped the new computer system will stop any of the footprints being recorded twice.