Need for Tiger Conservation

All India Tiger Estimation (AITE)

All India Tiger Estimation process was carried out by the intense observation and monitoring by NTCA (National Tiger Conservation Authority) and the State Forest Departments.

State Level Tiger Estimation (Phase IV)

As per the guidelines of the NTCA, the state level tiger estimation is carried out in the entire Sundarban landscape. This is known as Phase IV of tiger estimation. Camera trapping method is the only way of knowing the tiger population in this terrain.

Significance of tiger estimation exercise :

The Tiger estimation exercise that includes habitat assessment and prey estimation reflects the success or failure of Tiger conservation efforts.

Tiger Monitoring Techniques :

Smart technologies are regularly used from the AITE (All India Tiger Estimation) 2018 to till date.

• M-STrIPES application in android mobile gadgets for patrolling and protect tiger habitat.
• Camera Trap method is also exercised in STR in the winter season.

Note: The analysis of the flanks and the identification procedure of tigers are assisted by the WII-Dehradun.

Achievements of Sundarban Tiger Reserve:

• In West Bengal, Sundarban Tiger Reserve is in a leading position to conserve and monitor the endangered Royal Bengal Tigers.
• The tigers are increasing in numbers in STR.

Tiger abundance in Indian Sundarban over past cycles of All India Tiger monitoring :

Tiger Distribution and Density :

• In Sundarbans, tigers occupy 1895 sq. KM in 2022 (AITE 2021-22).
• A total of 713 camera trap stations were active for 25264 trap nights across the tiger bearing mangrove habitat of Indian Sundarbans.
• This yielded 849 photographs of tigers from which 100 individual tigers were identified.
• 81 tigers were photo captured in Sundarban Tiger Reserve, and 20 tigers were photo-captured in adjoining South 24 Parganas. However, one tiger was common between two divisions.
• The best model for estimating tiger density took into account the heterogeneity associated with tiger gender for both the detection probability at the activity centre and the movement parameters.

Density Estimation :

• Tiger density was estimated as 4.27 (SE 0.43) tigers per 100 sq. KM.
• The g0 (detection at activity centre) for females was 0.009 (SE 0.0006) while for males it was 0.007 (SE 0.0005).
• The σ (movement/scale parameter) for females was 4.1 (SE 0.1) km while for males it was 6.4 (SE 0.2) km.

Sex ratio estimation :

The detection corrected sex ratio was 2 females per male.

Remarks :

Sampling protocol of Sundarban and mangrove landscape differs from peninsular India. To estimate herbivores and prey species, boat transect were done during low tides, and khal (water channel) surveys were done for occupancy of tigers and other species. For the very first time the entire landscape was sampled using android based Polygon Search application of M-STrIPES.