As India prepares its long-delayed national census, set to conclude by March 1, 2027, with earlier start in snow-bound regions in October 2026, authorities face a critical dilemma: how to account for the Sentinelese, the world’s most isolated tribe living on North Sentinel Island in the Bay of Bengal.

Designated a tribal reserve in 1956, the island is legally off-limits to outsiders; even Indian officials avoid contact due to the tribe’s known hostility and extreme vulnerability to external diseases. Estimates of their population vary widely, 2011’s census unofficially recorded as few as 15 individuals, though experts now estimate between 50 and 400.

Authorities are exploring remote monitoring methods such as drone surveillance to estimate numbers without direct contact. Yet, the ethics and accuracy of such indirect methods remain deeply contested. Experts and indigenous rights groups warn that any effort to physically reach the island could threaten the Sentinelese’s health and survival.

While India readies the largest peacetime enumeration in history, with digital tools, caste inclusion for the first time since 1931, and participation options via mobile apps, how to account for those who refuse all contact remains unresolved.