Nagpur: Challenging long-standing metrics used to monitor and conserve endangered tigers across Asia, a new 13-year study from the Wildlife Institute of India (WII) and Panthera, the global wildcat conservation organization, has identified more reliable and robust metrics to qualify recovery of tiger populations and success of conservation initiatives.
Conducted from 2004-2017 in northern India’s Rajaji National Park, the study, whose findings were recently published in the journal Biological Conservation, cautions against relying on solely tiger population increases and densities at local and national scales, metrics which have served as the traditional standard of success across tiger range for decades.
Instead, the study finds that both the survival rate of tigers and how long female tigers remain in habitat and have litters at individual sites are more reliable benchmarks for certifying long-term population recovery and success.
Panthera chief scientist and tiger programme senior director Dr John Goodrich stated, “This study identifies critical metrics, right under our nose, that can help improve how we monitor tigers and ultimately implement conservation initiatives carried out on the species’ behalf across Asia.”
Goodrich continued, “What is also telling about the study’s findings is the incredible resilience of the tiger. Given the right circumstances, including abundant prey, threats kept in check and connections to other tiger populations, the species can and will return from the brink.”
The study monitored three different habitats in Rajaji National Park to identify conditions facilitating tiger population recovery. Connected to a large source population of tigers in the Corbett Tiger Reserve, the first region was absent of people and livestock, leading to an increase in prey like spotted deer.
The tiger population density tripled to 7 tigers/100 sq km, similar to estimates known from other well-protected sources sites across the range. But more importantly, female tigers maintained their ranges in the habitat for an average of 4 years, during which they produced 13 litters.
In the second habitat, connected to the first protected region, which is still home to families with livestock, tiger density increased, but the survival rate was lower. Females remained for an average of only one year, with just one female producing a litter. Finally, in the third area, unconnected to the first two regions, only two female tigers remained, making its population functionally extinct.
Panthera assistant tiger program director and lead author Dr Abishek Harihar stated, “Our findings highlight how critical site-based long-term monitoring is for evaluating the effectiveness of conservation actions for recovering tigers. Moving forward, Panthera will more rigorously measure tiger survival and female land tenure, and include these metrics in assessments and conservation plans of core tiger areas.”
Tiger populations have plummeted in the last century from 1,00,000 to about 3,900. In recent years, the illegal poaching of wild tigers has significantly increased to meet the demands of a $20 billion a year illegal wildlife market.
Through the Tigers Forever Program, Panthera is working to increase wild tiger populations by 50% over ten years. The program is training and outfitting local law enforcement and scientists to monitor tigers and secure tiger habitats from poachers, including stopping poaching before it happens using PoacherCams — the world’s first camera that can distinguish between people and animals and alert law enforcement about poachers in real time.