Among the 36 cat species, tigers are most closely related to lions, leopards, and jaguars. These cats evolved from a common ancestor that was probably similar to modern leopards or jaguars and lived more than 5 million years ago. The earliest fossils clearly identified as those of tigers are about 2 million years old. These fossils were found in central Asia, eastern and northern China, Siberia, Japan, Sumatra, and Java. Based on fossils dating from 300,000 to 10,000 years ago, some scientists think that tigers may have ranged into present-day Alaska via the Bering land bridge that once joined Alaska and Siberia during the last glaciation in the Pleistocene Epoch. Other scientists believe that the big cat fossils found in Alaska all belong to lions.
Scientists use a variety of methods to study the behavior of tigers and track their movements. Radio tracking was first used to track tigers in Nepal in 1973. In this method, a collar with an attached radio transmitter is placed around the neck of a tiger. Scientists monitor the radio transmissions as the tiger travels, tracking the tiger’s whereabouts to learn about its range, life history, and behaviors. More recently, scientists have set up camera traps that are triggered by an infrared beam. When a tiger crosses the infrared beam, the camera snaps a shot of the tiger, recording the date and time the photograph was taken. The tiger’s unique stripes help identify the animal, and when the same animal triggers other camera traps, the photo archives enable scientists to gather information about the tiger’s movements. This method helps scientists estimate tiger numbers in the wild.
An adult tiger defends a large area from all other tigers of the same sex. A female’s territory must contain enough prey to support herself and her cubs. A male’s territory is typically larger than a female’s territory—in addition to containing enough prey, the male’s territory typically overlaps with those of one to seven females in order to have access to females with which to mate.
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Thank you !