Patna, Sep 2 (IANS): The number of tigers in Bihar's only tiger reserve has more than doubled in the last three years, an official said Monday.

"We have counted 22 tigers in the reserve at present on the basis of camera trap census," Santosh Tiwari, director-cum-conservator of the Valmiki Tiger Reserve in West Champaran district said.

He said census was conducted by the VTR management in collaboration with World Wildlife Fund (WWF)-India.

Tiwari said the number of tiger was only 10 till 2010. "In last three years, the population of tigers has jumped like never before in the 899 sq km reserve."

He said that all of us including forest guards are happy. "This positive development is a matter of celebration," Tiwari said.

He said the National Tiger Conservation Authority (NTCA) would be informed about it soon.

According to him, VTR had started the tiger census work in February this year and 210 camera traps were used across the reserve for collecting data till June.

He attributed a friendly environment in the reserve for increasing number of tigers.

Tiwari said the improvement in the condition of grasslands, spread over 450 hectares, have been attracting the big cats for the last few years to the reserve, nearly 200 km from Patna.

Besides, intensive patrolling by local youth played a major role to check entry of poachers and others in the reserve.

"Tigers are more safe than before," he said.

Tiwari said that a tigress gave birth to three cubs in the reserve a few months ago -- the second such development in the area in one-and-half years.