The Case of the Northern White Rhino: Can science save a species that is functionally extinct?7 min read

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Imagine a sunset over the horizon of a Ugandan grassland. Now, picture a family of huge rhinos against the sunset grazing. A keeper watches over them affectionately but with desperation knowing that they are the last two of their kind
to walk the Earth.

This special is dedicated to the humbling story of Najin and Fatu, the last surviving members of the magnificent species of the Northern White Rhino.

The Northern White Rhino is the third-largest African animal in the world. The species is known for its wide mouth which was adapted for grazing grass as against the pointed mouth of the black rhino adapted to graze leaves and shoots. At one point, they were found in abundance across north-western Uganda, southern Chad, south-western Sudan, the eastern part of Central African Republic and north-eastern Democratic Republic of Congo (DRC).

But political instability and increasing demand for rhino horn (that is used in medicines) resulted in a sharp decline in their numbers.

The last ones standing

Meet the last of their kind by decoding this puzzle:

Till March 2018, there were three white rhinos in the world. One male rhino called Sudan and a mother-daughter duo, Najin and Fatu. But with Sudan’s death, the chances for the species to reproduce naturally crashed to zero.

Now the memory of the majestic species is embodied only in Najin and Fatu. For now, the species is functionally extinct.

A species is considered functionally extinct when its population is no longer viable. With no natural prospects of procreation, the northern white rhino falls in this realm.

But there is a journey to cover from functionally extinct to fully extinct and here, science can help.

Dr Thomas Hildebrandt, a Berlin-based expert in wildlife reproduction, spearheaded BioRescue to further research in the area and support the continuity of the species. Here’s the means they are deploying:

Surrogacy:

Surrogacy is assisted reproduction where a host womb carries a baby for intended parents. Here, the egg from a female species is fertilized with the sperm from a male member of the species and placed in the womb of a host species. Something similar is happening with the northern white rhino.

Before we move forward, let’s review a few terms:
Sperm: The male reproductive cell found in most animals.
Egg: The female reproductive cell found in plants and animals.
Fertilization: The process of combining the sperm and the egg. The result of fertilization is called a zygote.
Embryo: The unhatched or unborn offspring; a stage after the zygote formation

The stakes are high as there are no longer any living male northern white rhinos. In 2014, it was discovered that Fatu could not conceive naturally, and Najin had a tumor growing in her abdomen that would make the stress of pregnancy almost impossible to bear. A northern white rhino baby weighs 100 kilograms.

So a surrogate is essential!

In December, BioRescue harvested 14 eggs from Fatu. These eggs travelled overnight all the way from Nairobi to Italy.
The rescuers were in a hurry as unfertilized eggs cannot be frozen so they needed to be shipped to the location of the frozen sperm soon. Here the eggs were made to fertilize with the frozen sperm of a bull called Suni. Sperm was also collected from Sudan, the last male white rhino, but his age came in the way of the strength of his sperm.

Five viable embryos came out of this process. These have been frozen and preserved in liquid nitrogen.

Do you know that embryos can be preserved in liquid nitrogen for thousands of years?! This means that long after Fatu has walked the Earth, baby white rhinos could take their first steps on Ugandan soil.

In the next stage, these embryos will be planted in the surrogate, a southern white rhino female, a similar rhino which moved away from the northern white rhino around a million years ago.

But surrogacy is always a matter of chance. The number of frozen embryos limit the possibility of experimentation. Luckily scientists have another way.

Stem Cells Reproduction:

Stem-Cells are a type of primitive cells that can reproduce to create any kind of cell. They can generate everything from heart tissue to skin cells. 

Do you recognise this image from Owliver’s archives?
Click on it to know how this species uses stem cells.

Scientists are tapping into the power of stem cells to artificially create northern white rhinos.

In a path-breaking study, scientist Shinya Yamanka found that skin cells can be turned into sperm cells and egg cells. These rhinos would be created in laboratories in test tubes. Hildebrandt believes that enough skin cell samples exist to create a healthy population.

It is possible that in 20 to 30 years, surrogates and test tubes will restore the population of northern white rhinos in Uganda.

Human(e) connect

Najin and Fatu are presently in the care of their keeper, James Mwenda. For him, they are his family.

I’ve watched their numbers fall from seven to two … Working with them and watching what’s happening – it’s an emotional freefall. But I’ve dedicated my life to it.”

James Mwenda, The Guardian

 The people behind BioRescue are also committed to the cause. Hilderbrandt sees it as a project to “repair a complex ecosystem” (The Guardian). Jan Stejskal, director of international projects for the Dvůr Králové Zoo, believes that it is impossible to ascribe value to an animal. He says, “It’s about more than subsistence. It’s deeper than that” (The Guardian).

While conditions seem bleak the human race can redeem itself with the intervention of science. It is all about the choices we make. With adequate research support and funding, this mammoth project can be realised. A certain set of choices led to the decline of this beautiful species, and a certain set of choices can help bring them back to graze the expansive Ugandan grasslands, and bring a smile to the face of a keeper like Mwenda.

Here’s keeping our fingers crossed that the legacy of Najin and Fatu continues for eternity.

Do you think animals experience loneliness? What about Najin and Fatu who are the only two of their kind in the world?

What about the specificity of numbers draws our attention to a species?

How do we decide which species is worth saving?

With excerpts from The Guardian, NY Times, and Time