According to one of the most thorough wildlife studies ever carried out, there are more Indian tigers.
The number of tigers has increased by 6% to about 3,000.
The extensive study could provide a new global standard for measuring large carnivores.
The good outcomes support India’s extraordinary tiger conservation initiatives.
massive effort
Large, lone predators detest being seen.
They owe their whole existence to their ability to sneak up on prey without being seen and then attack.
As a result, the tigers are useless while we are trying to count them.
But reliable population estimates are essential for effective conservation.
The Indian government has been conducting a national census of tigers and other wildlife every four years since 2006.
The project team does nothing short of amazing efforts to estimate the tiger population:
Nearly 318,000 habitat assessments were undertaken by 44,000 field workers in 20 states in India where tigers are present.
For tigers and their prey, an area of 381,400 km2 (147,000 square miles) was inspected.
(The Guinness Book of World Records has received an application to determine if this is the largest wildlife survey ever carried out anywhere in the world.)
In 139 study sites, the scientists installed paired camera traps at 26,760 places, and these captured nearly 35 million images (including 76,523 tiger and 51,337 leopard photos).
These camera traps captured 86% of the distribution of tigers in India.
Robust models calculated population sizes in the 14 percent of the tigers’ distribution where it was too risky to conduct fieldwork due to political unrest.
Track the tigers.
The time spent gathering this much data would be completely wasted if it were not properly analyzed.
To sort the photos, the teams sought guidance from some of the top experts in the world. These experts included pattern matches who could determine whether a photo of a tiger taken during the monsoon season matched a photo of a tiger taken during the dry season while walking at a different angle, machine learning specialists who could quickly identify species and spatial analysis specialists who could calculate the populations of tigers and their prey.
The research team used this guidance together with their understanding of the ecology of tigers to create a census that is distinct from other large carnivore investigations.
We were fortunate enough to be among the scientists from outside of India who were asked to examine this procedure.
Peer review is an essential component of all scientific endeavors, but it is especially vital given how unreliable early surveys of Indian tigers were.
Actual figures
How did they fare then?
2,461 distinct tigers older than a year of age were photographed in all.
2,967 tigers were thought to be present in India’s whole tiger population (with an error range of roughly 12 percent).
83.4 percent of this was calculated using camera-trap images, while the remaining 9 percent was approximated using reliable modeling.
The number of tigers has climbed by 6% annually, maintaining the rate of growth from the 2014 census.
For Indian conservation efforts, this is a fantastic victory.
But not everything is rosy.
Tiger habitat has decreased by 20% from 2014 to the present, despite tigers moving into some new places (some 8 percent of their Indian range is new).
Yadvendradev Jhala and Qamar Qureshi, the survey’s coordinators, conclude that while established and safe tiger populations have grown in some regions of India, small, isolated populations and those within corridors connecting established populations have vanished.
This emphasizes the need for conservation initiatives to concentrate on enhancing the connection between isolated populations, while also encouraging the relocation of humans out of critical tiger regions, decreasing poaching, and restoring habitat to boost prey availability.
With India’s rapidly growing population, this won’t be an easy undertaking, but private tourism companies’ investments in the land purchase along corridors and the establishment of community conservancies could help complement government funding for the expansion of protected corridors.
The governments of Nepal and Bangladesh have hired the same project team to assist in estimating their tiger populations as a result of the success of India’s census.
Other iconic, charismatic species that can be uniquely identified using these techniques include jaguars in South and Central America, leopards, cheetahs, hyenas in Africa, and possibly even quolls in Australia.
