Can tiger return to a landscape? Assessing the potential for tiger
recovery using long-term prey-base survey as an indicator.
Abstract
Prey abundance is recognized as a key component for the recovery of the
tiger ( Panthera tigris) population. Long-term monitoring is imperative
for understanding the trends in prey populations and helps assess the
management interventions. We provide data on the tiger prey populations
that include chital ( Axis axis) , chousingha ( Tetracerus quadricornis)
, nilgai ( Boselaphus tragocamelus), sambar ( Rusa unicolor), and wild
pig ( Sus scrofa) from Kawal Tiger Reserve (KTR) for a period between
2010–2022. We conducted our study using 28 permanently marked transects
in a systematic survey design with a random start. The trends in the
principal tiger prey populations were also compared across the years.
The chital population has shown a significant rise but sambar, nilgai,
and chousingha populations were consistent with a slight increase. The
wild pig population was typically showing extreme fluctuations. We used
the prey-biomass and prey-abundance-based models to predict the
ecological carrying capacity of tigers. Based on the prey availability
at KTR, we predicted that the reserve could potentially support more
than 30 tigers in its core area. However, in the past 10 years, tigers
have failed to recolonize KTR despite the movement of 11 tigers from the
source sites of which only 2 were females. Therefore, we suggest that
establishing a breeding tiger population may need restocking, focusing
on the females, and maintaining connectivity with the tiger landscapes
in neighbouring Maharashtra State having Protected Areas with a healthy
source population. After being declared a tiger reserve in 2012, the
level of protection in KTR has increased but the anthropogenic stressors
are yet to be fully dealt with. Our long-term monitoring study has
systematically documented the trajectory of prey populations and we
predicted a significant increase in the carrying capacity of tigers in
the Core of KTR.