A giant rat has been discovered in New Guinea

At an altitude of almost 4,000 metres, amid the misty mountains of New Guinea, a researcher from the Czech Republic has done what no one has ever managed before. Biologist František Vejmelka became the first to film the mysterious giant woolly rat Mallomys istapantap, one of the largest rodents in Australia and Oceania, in the wild.

Previously, this nocturnal giant was known only from museum specimens. It wasn't described until 1989, but no one had ever seen it alive. Until now.

📸 A rat the size of a cat in the lens

Cameras recorded the rat moving through the forest, hiding during the day and going out to hunt for plants at night. Its body length together with its tail is 85 cm and its weight is almost 2kg! It has long paws (up to 8 cm), powerful teeth and thick fur. And despite its size, it has remained invisible until now.

Why? It's simple: it lives in inaccessible mountains, is nocturnal and avoids humans.

🏕️ A six-month expedition

To find this mysterious beast, Weimelka spent 6 months in the mountains, climbing up to 4,500 metres. He was assisted by local hunters, without whom, he says, nothing would have been possible.

During the expedition, he documented 61 species of mammals, including marsupials and other rare rodents along the slopes of Mount William, the highest point in Papua New Guinea.

In addition to photos and videos, the scientist took measurements of the animals and studied their diet, activity, parasites and behaviour.

🌍 Why it matters

Weimelka was the first ever to document the behaviour of this species in its natural habitat. His work is not just a beautiful wanderlust report. It is a contribution to the study of tropical mountain biodiversity, which until now has remained a white spot on the map of science. Especially in Australasia, in contrast to the jungles of South America and Southeast Asia, which have been studied in much greater depth.

In addition, the project was an example of how global science and indigenous knowledge can complement each other. Local people not only helped in the search, but also learnt more about the rare animals of their homeland - and why they should be protected.

Details: František Vejmělka, First scientific observation of the largest Sahulian rodent, Mallomys istapantap, in the wild, Mammalia(2025). DOI: 10.1515/mammalia-2024-0153