Monday, January 01, 2018

Sumatran Rhino's 12,000 Year March to Extinction

Update: Some good news to begin the new year here at PNG! Iman, (see below) Malaysia's last surviving, captive female rhino has come out of her mud wallow and is recovering from a bleeding tumor in her uterus.  An intensive course of medication and controlled diet has reversed her deterioration according to her keepers.  Conservationists were worried that Iman would die, leaving no hope for a captive breeding program in Malaysia. Iman is believed to be fertile, so she represents the only source of rhino eggs in the country. The technology to freeze, preserve and thaw their eggs does not exist.  An earlier urgent request for frozen sperm to inseminate females was ignored by the Indonesian government which has a much larger program underway.  Iman is not out of the forest yet, as she has not resumed her normal eating habits and there is still some bleeding from her reproductive organ. She is given intravenous supplements and her favorite foods to encourage her full recovery.   Iman and her male partner, Kertam, live at the Tabin Wild Life Reserve under the care of BORA, the Borneo Rhino Alliance.
Ipuh died in 2013

{18.12.17}A new genetic study of the soon to be extinct-in-the wild Sumatran rhinoceros, (Dicerorhinus sumatrensis) shows that the species'  population peaked about 12,000 years ago. It has been in decline since then. The end of the last ice age when sea levels rose precipitously, cut off most of its former territory. Less a natural cause be used as an excuse to end conservation efforts, it is noted that man contributed greatly to the rhino's decline by destroying its remaining rainforest habitat and hunting for its horn and hide.  Their genetic isolation and solitary lifestyle made them more vulnerable to existential threats, so their population bottomed out and never made a recovery.  John Payne, director of BORA (Borneo Rhino Alliance), called the new study results "fascinating" but cautioned interviewers that, “To say that we should just let some species go extinct because it is ‘natural’ is nonsense.”

The study was published in Current Biology and used genes from Cincinnati Zoo's deceased male rhino, Ipuh. [photo above] The genome analysis showed that rhino population peaked at about 57,800 individuals, but by the end of the Pleistocene that number plummeted to just 700.  Today, an estimated 30 survive in the wild in four distinct population groups. The official estimate is 100 but that is considered overly optimistic by experts.  The Sumatran is the only surviving member of the genus, Dicerorhinus, so its loss to Nature would be a huge loss indeed.  It is a genetic relic of a large family of rhino species that roamed the Eurasian continent 15 to 20 million years ago and included the woolly rhinoceros, which was hunted to extinction 10,000 years ago by Homo sapiens.

Conservation efforts have been hampered by a lack of support from the Indonesian government. According to, a fragile consensus was reached between experts that more rhinos must be captured from the wild and brought into places like the Sumatran Rhino Sanctuary (SRS), where a captive-breeding program is underway. The recommendations include taking all rhinos out of Indonesian Borneo and Bukit Barisan Selatan National Park, in southern Sumatra and Kalimantan. “Even more important,” according to a meeting document, is catching fertile rhinos from the Way Kambas population. All of these recommendations were passed to officials, but no official action has yet been taken.

Breeding in captivity has its problems too. Sumatran rhinos are slow breeders. Females do not reach sexual maturity until the age of 6 or 7, and males 10. Females only mate once every four or five years, and the species’ gestation period is 16 months. Juveniles stay with their mothers for two to three years.  Previous attempts to capture fertile animals have been botched. More bad news occurred recently when the last captive female in Malaysia, Iman, fell seriously ill due to a bleeding tumor in her uterus. Treatment is difficult say her caretakers because she refuses to eat or leave her mud wallow. [photo credit: BORA] Another female, Puntung was euthanized in June after suffering from squamous cell cancer for three months. The hopes of the captive breeding program were quashed when doctors were unable to recover any fertile eggs from Puntang. {08.06.17}