If you are concerned about the declining number of tigers and their prey, you can get trained to do a survey on your own. On Youtube. The Wildlife Conservation Society
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/you-can-count-tiger
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/down-earth
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wildlife
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tiger
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment-education
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wildlife-conservation-society-wcs-india
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india