We don’t know how many animals are born every day on our little blue planet. But given the fecundity of insects, it’s probably in the billions — and maybe in the trillions or even quadrillions. So, it’s a rare occasion when one of these births makes global news — but then there’s nothing in the world like a Sumatran rhino (Dicerorhinus sumatrensis).

On Sept. 30, the Indonesian government announced the birth of a female calf at the Sumatran Rhino Sanctuary (SRS), bringing the number of captive Sumatran rhinos to 10.

The Sumatran rhino, the smallest of the world’s five rhino species, is arguably the world’s most endangered large land mammal (depending on the status of the saola). Populations of Sumatran rhinos have been plummeting for decades in the wild until most have winked out entirely. An estimate last year put the total number of wild Sumatran rhinos at just 34-47 animals. Only one population, in Gunung Leuser National Park at the northern tip of the island of Sumatra, may have enough rhinos for even short-term survival.

All this makes the news of the birth of another rhino even more momentous. The baby entered the world weighing 27 kilograms (59.5 pounds). Sumatran rhinos are born fringed with hair and sporting googly eyes. The hair lessens as they age, but they’re still the world’s hairiest rhinos, related to the extinct woolly rhino. Sumatran rhinos are the last rhino in the Dicerorhinus genus, making them only distantly related to the four other living rhino species.

“There are so many uncertainties about the status of wild Sumatran rhinos, but with this birth and the overall success of the SRS breeding program, there is clearly still hope for this species,” Nina Fascione, executive director of the International Rhino Foundation (IRF), said in a press release. Fascione traveled to Sumatra to be there for the birth.

The offspring of mother Ratu and father Andalas, the unnamed baby is the fourth for the SRS going back more than a decade. This is also the third calf for Ratu and Andalas, making them the power couple of the SRS. Last year, Ratu and Andalas’s eldest, a male named Andatu, sired a calf with another Sumatran rhino, Rosa. With these four births, the staff of the SRS have proven they can successfully breed and rear young, even with only a few animals to work from.

“This news is certainly happy news, not only for the Indonesian people but also the world,” Siti Nurbaya Bakar, Indonesia’s environment minister, said in a press statement. “I give my highest appreciation to the parties involved in the birth of this Sumatran rhino.”

Despite this, criticism has been ramping up of Indonesia’s handling of its rhinos, both the Sumatran rhino and Javan rhino (Rhinoceros sondaicus), which is also one of the most endangered land mammals in the world.

Indonesia announced a plan in 2018 to catch more Sumatran rhinos from the wild for its successful captive-breeding program. To date, however, only a single rhino has been captured. At the same time, Indonesia has failed to release a promised Sumatran rhino census, though sources from the field say the numbers are grim. Making matters more urgent, the rhinos in the wild continue to vanish and the rhinos in captivity are increasingly interrelated. All the captive males, just three, are closely related.

“Not only are we implementing natural reproduction efforts, technological assistance is also needed to optimize the breeding of Sumatran rhinos,” Jansen Manansang, executive director of the Indonesian Rhino Foundation (YABI), said in a press statement. Jansen said that YABI, which manages the SRS for the Indonesian government, has plans for assisted reproductive technology, or ART.

To date, Indonesia has shunned using any drastic reproductive technologies to produce more rhinos. Yet, one of its captive rhinos, Pahu, could provide much-needed genetic diversity to the small captive pool. Captured in 2018, Pahu is a female Bornean rhino, a distinct subspecies from those found in Sumatra. Sources say she’s unable to carry a pregnancy to term herself, but employing ART could allow her genetics to still be utilized by extracting her eggs for potential implantation in another rhino. The technology is there: in 2021 scientists created rhino embryos from the critically endangered northern white rhino, a functionally extinct subspecies.

Even with this happy birth in September, time is continuing to run out — and options are closing — for the Sumatran rhino. The success at SRS ensures another generation of rhinos, but more animals are needed to ensure these hairy rhinos survive the next century.

Banner image: The newborn rhino calf with her mother, Ratu, at the Sumatran Rhino Sanctuary in Way Kambas, Indonesia. Image courtesy of the Indonesian Ministry of Environment and Forestry.

Related audio from Mongabay’s podcast: A conversation with conservation biologist Wulan Pusparini, who has spent much time in search of the remaining rhinos left in the wild, listen here:

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New estimate of less than 50 Sumatran rhinos shows perilous population drop