Volkswacht Bodensee - Two of a kind: Najin and Fatu, the last northern white rhinos

This might sound like a common parental complaint, but Najin has a particularly strong argument -- she and her daughter are the only members of their species left on Earth.

They are the last two northern white rhinos, which have been considered functionally extinct since Najin's father, Sudan, died in 2018.

Uterus problems mean neither can give birth, so scientists are trying in-vitro fertilisation to bring northern whites back from the brink.

Earlier this month, AFP met the two rhinos inside their heavily guarded enclosure in Kenya's Ol Pejeta Conservancy.

- Najin, the lonely mum -

Both Najin and her daughter were born in captivity in a Czech zoo before being moved to Ol Pejeta in 2009.

Najin has bad knees owing to her time in captivity, and her horn droops forward.

She is also prone to bouts of flatulence.

At 35 years old, she is only expected to live another five to 10 years.

"I'm getting a little bit worried," admitted head caregiver Zacharia Mutai, who spends 12 hours with the rhinos most days.

"They have different personalities just like human beings," he told AFP.

Najin is his "favourite" because she stays so calm, he said.

At one point, the inquisitive rhino lumbered up to inspect a camera tripod, sending AFP's correspondents scampering.

Najin also inspected a nearby car in the 700-acre enclosure.

The rhinos are under 24-hour protection, with a watchtower, armed guards and sniffer dogs to deter poachers who have hunted northern whites to the brink of extinction.

There has been no poaching at Ol Pejeta for seven years, Mutai said. The only intruders in the enclosure are now antelopes that nimbly leap over the fence, and some wandering warthogs.

But aside from Mutai, Najin seems to spend most of her time by herself.

- Fatu, the grumpy teen -

Born in 2000, Fatu was much younger when she came to Ol Pejeta and has embraced being wild more than her mother.

She spends almost all her time with Tawu, a wild southern white rhino introduced to demonstrate life outside a zoo.

Southern whites are a closely related subspecies that had their own brush with extinction in the 1800s, but now number more than 15,000.

They look similar -- both are grey, not white -- but the northern subspecies are smaller, with fluffier ears and slightly longer tails.

Fatu, who turns 25 in June, was initially quite friendly when she arrived at Ol Pejeta.

She has become "a little bit grumpy" and "behaves sort of like a human teenager", said Mutai.

Fatu sometimes tries to fight Najin, forcing the rangers to trim her horn so she does not wound her mother.

She also has the fate of her kind resting on her shoulders.

Fatu once tried to mate, but it turned out there was a problem with her uterus.

Unlike Najin, she still has viable eggs that can be fertilised with the sperm of dead males.

Fatu must be fully sedated each time scientists collect her eggs.

That has happened more than 20 times, making her probably the most sedated rhino in history, but Fatu remains in perfect health, said Jan Stejskal, coordinator of the BioRescue project aiming to save the northern white.

The scientists plan to start implanting the first northern white embryos in a southern white rhino surrogate female this year.

If successful, it would give Fatu and Najin a new purpose: to show the baby how to be a northern white rhino, so this is not lost to time.

It is a "huge responsibility", Mutai said, adding: "I think we are going to succeed."

U.Maertens--VB