Some of Australia's most endangered animals have dangerous sex lives.

The northern quoll is facing threats from feral cats and cane toads. But their own weird sex lives are not helping their cause to survive.

Each year during mating season, males in the species spend three furious weeks looking for partners, mating and then when the job is complete they die.

Jaime Heiniger is a PhD student at the University of Queensland and has been studying the northern quoll on Groote Eylandt, in the Gulf of Carpentaria, east of Arnhem Land.

For the past three years she has spent several months each year, catching and observing the animals in their natural habitats.

'We haven't had one male survive,' she says.

The male quolls reach sexual maturity at the age of around 10 months.

Ms Heiniger says upon reaching maturity, the quolls increase their home base from one square kilometre to ten square kilometres as they search for a mate and fight off other males.

'They breed for 2-3 weeks, they lose half their body weight and their hair,' Ms Heiniger said.

'All the males die. We haven't had one male survive.'

Although other animals are known to die after mating, it is highly unusual in mammals.

To find out what the quolls get up to each day, just before sunset, Ms Heiniger sets up to 40 traps on rocky escarpment in one section of the island.

At sunrise, she gets up early to check the cages and can find anywhere between eight and 28 trapped quolls.

The trapped quolls are measured, blood samples are taken to identify their genetic make up, and then GPS collars are attached before the animals are released into the wild.

Over a three week period the collars collect information on things including where and how far the quolls go.

If the quolls are trapped again, the GPS collars are removed and information from the collar is collected and used for research purposes.

Northern Quolls are threatened across large parts of northern Australia. The information being gathered by Ms Heiniger and the other rangers on Groote Eylandt will be used if new quoll communities and habitats need to be established.

'We hope the information we gather can be used for management of quolls and how to increase populations in a natural setting for breeding programs,' Ms Heiniger said.

Female quolls can have up to 30 in their litter but with only eight teats, it becomes a race to see which newborns will find a teat and survive.

What's not known yet is whether all the young are fathered by the same male quoll.

'No-one has looked at how many different fathers there may be,' Ms Heiniger said.

It's hoped information gathered from blood samples will help answer that question.