The death of three leopard cubs is a major blow to reintroduction efforts in India

(CNN) — Three leopard cubs died in India this week, a further setback to the government’s historic attempt to reintroduce the species to the country after 70 years.

Chiaya, one of eight leopards rehabilitated to India’s Kuno National Park in the Madhya Pradesh state of Namibia in September last year, was among four cubs born in late March.

The first cub died on Tuesday morning, JS Chauhan, chief superintendent of forests in the central Indian state of Madhya Pradesh, told local media. Over the next two days, two more cubs died of “heat, dehydration and weakness”, forest officials said.

A fourth cub was also rescued and taken to a local hospital for follow-up, Chauhan said.

“Her condition is also not good, but the puppy is doing very well after treatment, though she is underweight and a bit weak. Both the mother and the puppy are still under observation,” he added.

The government did not reveal the cause of death, but the day they died was one of the hottest of the season, with temperatures reaching 46-47 degrees Celsius.

The latest deaths bring to six the number of leopards killed since their reintroduction in India.

Cheetahs were declared extinct in India more than 70 years after Chiaya gave birth to cubs. It took a multi-legged journey to get her and seven other cats from Namibia on the southwest coast of Africa to central India.

Another 12 leopards arrived from South Africa in February.

But three-year-old leopards died after that. A South African cheetah died during a courtship and mating attempt, a Namibian cheetah died of kidney disease and a South African cheetah died of heart failure.

According to the Smithsonian’s National Zoo, cub mortality is highest in the wild and in captivity. On average, 30% of cubs born into human care die within a month of birth, and about 90% of cubs in Tanzania’s Serengeti National Park die before three months, according to the zoo.

Leopards were declared extinct in India in 1952. These are the only large carnivores in the country that have ever experienced that fate.

Today, spotted cats are most common in Kenya and Tanzania in East Africa and Namibia and Botswana in Southern Africa, according to the National Zoo. But historically, these endangered cats had a much larger range, roaming the Middle East and central India and much of sub-Saharan Africa.

Habitat loss, poaching and conflicts with humans have drastically reduced their population. According to the Cheetah Conservation Trust, today only 9% of their historic range remains, with fewer than 7,100 adult and juvenile cheetahs left in the wild.

Tara Subramaniam, Manveena Suri and Joe Sottle contributed to this report.