Nature
PUBLISHED
The planet is (quite literally) burning and the world's two biggest nuclear powers have decided to step away from the Intermediate-Range Nuclear Forces Treaty (INF), raising the possibility of a new nuclear arms race – and so, to end the week on some good news, here's Edward.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Edward is the latest addition to the San Diego Safari Park's clan of southern white rhinos. (Side note: The true and proper name for a collective of rhinos is a crash.) He was born to Victoria on July 28, 2019, the wildlife center revealed in a press release.
However, it was not just any bog-standard birth. Edward was conceived with a little help via artificial insemination. This is exciting because artificial insemination has rarely been successful in southern white rhinos – in fact, this is the first time it has been successfully carried out in North America – and it could pave the way for similar treatments in their cousin, the northern white rhino.
"All of us at San Diego Zoo Global are elated with the arrival of this special rhino calf," Barbara Durrant, PhD, Henshaw endowed director of Reproductive Sciences, San Diego Zoo Global, said in a statement. He is already "up and walking, and nursing frequently. Not only are we thankful for a healthy calf, but this birth is significant, as it also represents a critical step in our effort to save the northern white rhino from the brink of extinction."
The process started over a year ago when Victoria was artificially inseminated with frozen semen from a male southern white rhino on March 22, 2018, after a hormone-induced ovulation. White rhino gestation periods are typically around 16 months – which is long but not quite as long as that of elephants (up to 22 months), who have the not-so-enviable distinction of being the mammal with the longest gestation period. Victoria carried Edward for 493 days.
Following the tragic death of Sudan last year, there are just two northern white rhinos remaining – and both are female. Research last year revealed they were much closer genetically-speaking to their southern counterparts than previously thought, raising hope that with a little intervention (and cross-subspecies breeding), there may still be a future for the northern white rhino.
But there are still a number of hurdles to meet. That includes converting cells from 12 northern white rhinos (held at San Diego Zoo Institute for Conservation Research’s Frozen Zoo®) into stem cells that, in turn, could develop into sperm and eggs. According to the press release, this process has already successfully begun at The Scripps Research Institute.
If accomplished, there are various reproductive options available, including artificial insemination (as was done here), in vitro fertilization (IVF), and embryo transfer – all using southern white rhinos as surrogates. Researchers have hope that a northern white rhino calf could be born within 10 to 20 years. If successful, it could help other endangered species of rhinos too.
