Camera Trapping
During 2012-13, the process of Camera Trapping was continued as a part of Phase IV Tiger Estimation in Indian Sundarbans. The four Ranges of Sundarban Tiger Reserve was covered by the following two Organization for Camera Trapping Exercise:

Range(s) Covered

Organization

SWLS, NPE & Basirhat

WWF

NPW

WWI



The sampling period was selected during the winter period i.e from November to March taking care of weather and other parameters suitable for carrying out the exercise.

Methodology:


The tidal fluctuation from the data available through tide tables (Survey of India, 2011) was analysed. The study area was divided into grids of 4 sq km each. Geo-coordinates of suitable sites were recorded using a handheld GPS receiver (Garmin 72H). These tracks and points were overlaid over gridded high resolution image in geographic information system domain using MapInfo 8.5. The grids were selected based on the following criteria: (i) presence of tiger sign (pugmarks) and (ii) comparatively high elevation areas which were unlikely to get submerged.
            Cuddeback (Attack) digital scouting cameras with heat-motion sensors were deployed to capture tigers and other fauna. The minimum distance between two camera trap was at least 1 km, which is ideal for 2X2 sq km grid study design. To maximize tiger captures and as well as recaptures, olfactory lure was applied.
            Monitoring was carried out after fifteen days from the beginning of each session to check the status of camera traps and if required change the height of camera trap or select comparatively high elevation sites within the same grid. This is due to the high water mark in between the days which may otherwise inundate the cameras.

Detailed statistical records of Camera Trapping Exercise:

Forest Range

Total Area (sq km)

Total grids

Camera trap stations

Trapping area (sq km)

Sampling period (days)

SWLS

380

103

57

408

46

NPE

597

155

56

470

49

Basirhat

392

94

57

345

31

NPW

659

145

32

495

44

Results of camera trap exercise by WWF & WII:
Range
No. Of Togers
SWLS
17
NPE
27
Basirhat
13
NPW
22 + 1 (Cub)
Total
79 +1 (Cub)


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