The study - Tiger poaching and trafficking in India: Estimating rates of occurrence and detection over four decades - by wildlife biologist Koustubh Sharma along with Belinda Wright, Tito Joseph, Nitin Desai of WPSI, attempts to find the probability of tiger crime and its detection between 1972 and 2012 in 605 districts of India.

It finds that of the 73 hot spot districts, at least 17 show high probability of tiger crime despite being far from known tiger habitats. This points to the inability of local enforcement agencies to effectively curb tiger crime where it seems to be taking place through an organized network. Poor intelligence remains a stumbling block, says the study.

The illegal trafficking of tiger parts has two components - one, tiger poaching and, two, the selling, buying and smuggling of tiger parts out of the country. Between 82 and 88 districts have been identified as traditional and new trade hubs based on the number and kind of confiscations over the years and reliable intelligence inputs.

"We hypothesize that these tiger trade hubs underwent a change around 1999-2000, when the trade became more organized. Some hubs were abandoned and new districts became trade hubs, though many remained traditional tiger trade hubs at least for the past 40 years," says Desai.

The study is based on WPSI's database on poaching and confiscations from 1972 onwards and recorded information on confirmed incidents of illegal killing or trafficking of wildlife. The database consists of more than 25,000 entries on poaching, confiscations, raids, retaliatory killings and accidents involving nearly 400 wildlife species.

"During 2009-2012, the probability of tiger crime was high in 73 of the 605 districts. These can be considered the current hotspots for tiger crime. The areas with greatest risk of tiger poaching and trafficking are situated in a narrow corridor running from south India, through central India and all the way to specific border districts in the north," says Sharma.

A large number of districts are at high risk of tiger crime along India's border with Nepal - considered the main international hub for trafficking of tiger parts into China.

There has been a minor improvement in detection of tiger crime after 2005, possibly as a result of the revelation that there were no tigers left in Sariska.

The high-crime districts

Maharashtra: Nagpur, Amravati, Bhandara, Chandrapur, Gadchiroli and Kolhapur.

MP: Balaghat, Chhindwara, Hoshangabad, Indore, Jabalpur, Katni, Khandwa, Satna, Mandla, Panna, Umaria and Seoni.

UP: Allahabad, Lucknow, Pilibhit, Ghaziabad, Bijnor, Bahraich, Balrampur, Fatehpur, Maharajganj, Kanpurnagar,

Uttarakhand: Pithoragarh, Dehradun, Kheri, Nainital, Champawat, Udhamsingh Nagar, Haridwar, Pauri Garhwal

Karnataka: Bangalore; Bangalore Rural, Chamrajnagar, Chikmagalur, Dakshina Kannada, Mysore, Nilgiris, Mandya, Kodagu

Andhra Pradesh: Adilabad, Mahabubnagar, Hyderabad, Warangal

Assam: Barpeta, Nagaon, Kamrup

Odisha: Chhatarpur, Mayurbhanj

Chhattisgarh: Bilaspur, Bastar-Kanker, Raipur

Tamil Nadu: Erode

West Bengal: Darjeeling, Kolkata, Malda, Jalpaiguri, South24Parganas

Kerala: Coimbatore, Ernakulam, Idukki, Palakkad, Wayanad

Delhi-Haryana: Gurgaon, Sawai Madhopur, Sonitpur