Researchers tracking feral cats in Arnhem Land believe there are far more than they first estimated.

It is estimated that in some areas there is a feral cat every six square kilometres, meaning thousands are preying on native wildlife every night.

Scientists from Charles Darwin University and the Northern Territory Department of Land Resource Management have been working with traditional owners in Arnhem Land to learn more about the wild cats.

Using radio tracking devices, night-time surveys and camera traps, they estimate cat numbers and population density.

Ecologist Terry Mahney says feral cats are causing native animal numbers in Arnhem Land to decline.

"We know from research elsewhere that cats can drive animals to extinction," he said.

"Part of this project is firstly getting a better understanding of the cats' ecology, so we know where they are going, what they are doing, what their relationship is with the prey, and then looking at methods of control."

Some of the captured cats have been fitted with GPS radio-tracking collars to trace their movements.

As part of a three-year project so far, culling the cats has been tried with the help of local Warddeken Rangers.

Trapping is also being trialled this year.