Status of tigers, copredator and prey in Tadoba Andhari Tiger Reserve (TATR) 2021

Abstract

Phase IV monitoring for the Tadoba Andhari Tiger Reserve (TATR) core and buffer was conducted from February – May 2021 covering an area of 1315 sq. km. as a part of the project “Long-term Monitoring of Tigers, Co-predators and Prey in Tiger Reserves and other Tiger bearing areas of Vidarbha, Maharashtra”. The objective of Phase IV Monitoring is to estimate the minimum number of tigers in the reserve using Spatially Explicit Capture-Recapture Sampling and density estimation of prey base using Distance Sampling. Camera traps were placed in 621 grids of 2.01 sq. km. area each in the core and buffer area of TATR in two blocks. In each sampling block, camera traps were active for 27 - 44 days. During 83 days of camera trapping survey with a sampling effort of 20,965 trap nights, 85 adult individual tigers were photographed in the sampled area of TATR. Estimated population (N) of tigers based on the best fit (SECR Heterogeneity) model was 86 (SE ± 0.71). Tiger density per 100 sq. km. based on the Spatially Explicit Capture-Recapture (SECR) model was 6.31 (SE ± 0.70). Along with tigers 114 adult individual leopards were photographed in the sampled area of TATR and estimated population (N) based on the best fit (SECR Heterogeneity) model was 118 (SE ± 2.17). Leopard density per 100 sq. km. based on the Spatially Explicit Capture-Recapture (SECR) model was 7.07 (SE ± 0.67). To estimate prey density, 133 line transects in core and buffer of TATR were sampled 7 times during the sampling period, with a total walking effort of 1862 km. During the sampling, a total of 1163 animal/bird observations were made. The overall individual density per km2 of major prey species in TATR was Gaur 2.16 (SE ± 0.39), Sambar 1.71 (SE ± 0.29), Chital 2.65 (SE ± 0.55), Wild Boar 3.73 (SE ± 0.84), Langur 3.35 (SE ± 0.71), Barking Deer 0.42 (SE ±0.08), Nilgai 1.04 (SE ± 0.25), Black-naped Hare 0.68 (SE ± 0.15) Peafowl 1.79 (SE ± 0.25) and Grey Jungle Fowl 8.19 (SE ± 1.02). A basic understanding of sympatric carnivore ecology with asymmetric competition enables us to hypothesize that to coexist and not just co-occur there must be niche segregation on at least one of the three axes: space, time, and/or diet. To understand how three large sympatric predators co-occur in space and in time, camera trapping was carried out. Temporal activity overlaps were derived by using kernel density. All the sympatric predators were found to co-occur in the sampled area of TATR. There was a distinct difference in the space-use pattern observed for all three carnivores and a strong spatial segregation pattern found between Tigers, Dholes, and Leopards. It showed significant segregation and avoidance of each other’s space. There was a significant overlap between the temporal activity pattern of tigers and leopards. While tigers and leopards show a strong, unimodal, nocturnal activity pattern, dholes show a bimodal, crepuscular activity pattern.