New Delhi-Pointing to the possibility of an increase in the number of tigers according to the preliminary indications from the on-going countrywide Tiger estimation Census, Union Minister of Environment, Forest and Climate Change, Dr. Harsh Vardhan has reiterated the need to build a social movement for tiger conservation.Addressing the week-long Global Tiger Day celebrations Dr Vardhan underlined that social movements to create awareness in our country have often been built up with the help of children. In this context, the Minister quoted the example of spreading awareness on the spread of dengue some years ago and the movement for polio eradication. Similarly, children must play a leading role on creating awareness for tiger conservation, Dr. Harsh Vardhan averred.