Test tube rhinos - Northern White Rhino

Context: Scientists announced the first-ever rhino pregnancy achieved by transferring a lab-made rhino embryo into a surrogate mother.

Background

The last four northern white rhinos were brought to a conservancy in Kenya in 2009.
This population failed to breed in their natural environment because the two males died, and the two females turned out to be incapable of reproduction for pathological reasons.
Leaving surrogacy as the only viable option to produce a northern white calf through IVF.

The embryos are all from eggs harvested from two females and sperm taken from a few deceased zoo males, even multiple successes with IVF and surrogacy cannot build a gene pool large enough for a viable northern white population.
Babies will not be born genetically hardwired to behave as one of the species. They pick up those traits from family and social interactions. So, calves born to surrogate southern white mothers need to be raised by northern white adults to learn to be northern whites and carry that legacy for the next batch of IVF calves.

White rhinos are the second-largest land mammal (after elephants).
They are also known as the square-lipped rhinoceros, white rhinos have a square upper lip with almost no hair.
There are two genetically different subspecies that exist.
The Northern white rhino
The Southern white rhino

Difference

Northern White Rhino
They are relatively smaller 1400-1600 kg (adult male); have straight back and flat skull. They have no grooves between ribs; hairier ears and tails and shorter front horn.

Southern white rhino
They are larger 2000-2400 kg (adult male) in size have concave back and prominent shoulder hump. They have concave skull sometimes with distinct vertical grooves between ribs. They exhibit more body hair and longer front horn.

Northern White Rhino - Critically endangered

The subspecies is practically extinct in the wild due to being wiped out in their natural habitat of Sudan, Chad, Central Africa Republic, Democratic Republic of Congo and northern Uganda, by poachers.
The last two remaining northern white rhinos now live at Ol Petjeta Conservancy in Kenya, which is a private reserve to protect wildlife from poachers.

Southern White Rhino - Near Threatened

The majority (98.8%) of the southern white rhinos occur in just four countries: South Africa, Namibia, Zimbabwe, and Kenya.

Rhino Species and their IUCN status

S. No.	Species	IUCN Status
1	Indian Rhino (Greater one horned Rhino)	Vulnerable
2	Javan Rhino	Critically Endangered
3	Sumatran Rhino	Critically Endangered
4	Black Rhino	Critically Endangered
5	White Rhino	Near Threatened