On the brink

There are a few large mammals in the world literally living on the brink of extinction. The Asian rhinos immediately spring to mind. Both Southeast Asian species have been ruthlessly persecuted because their horn is more valuable per ounce than gold or cocaine—this despite the fact that science has proven time and again that it has no medicinal properties. Sumatran rhino (Dicerorhinus sumatrensis) numbers have been depleted to around 200 individuals. The Javan rhino (Rhinoceros sondaicus) is in even worse shape. A few years ago there were two remaining populations: one on the western tip of Java and another in southern Vietnam. In 2010 the last Vietnamese rhino was killed by a poacher. Now a single population survives in Ujung Kulon National Park—which is, incidentally, near an active volcano. There are thought to be 40 individuals left. Tigers are in trouble everywhere. Unless current trends are reversed they may gone in the wild within our lifetime. Since the 1970s three of the eight recognized tiger subspecies have gone extinct.

I suspect that most people are aware that rhinos and tigers are endangered. But how many people also know that the Saola is facing extinction? It doesn’t have the high profile that rhinos and tigers have. This is a shame, because it may be the most critically endangered large mammal in Southeast Asia. It is believed to occur in less than fifteen forest blocks across its entire range. Precise population estimates are impossible to make given our inability to reliably detect and monitor the species. If things are good the global population could be as high as 350. If things are bad it could be in the tens. In my opinion the real number is closer to the lower end of that range. Without immediate conservation action the Saola could be extinct within the next few years. As a reminder: there are no individuals in captivity. The world may lose this spectacular species just twenty years after it was discovered by science. But why is the Saola in such a deplorable state? Why is the Saola on the brink of extinction while other Annamite ungulates, such as the serow, maintain healthy populations? Serow numbers have certainly been depressed from historic levels but no conservation biologist would consider listing it as critically endangered. What is it about the Saola?

Saola global distribution
Saola global distribution

There are several reasons. One simple reason is that the Saola has a highly restricted range. It is found only in a narrow belt of forest along the border between Laos and Vietnam. Why is it only found in this area? All available evidence indicates that the Saola is a habitat specialist: it only occurs in wet evergreen tropical forest. It is unclear to biologists why the Saola has such narrow habitat requirements but it’s likely that this specialization is linked to dietary requirements. Put simply: the Saola’s zip code is very small. This is problematic from a conservation perspective. Let’s again turn to the serow as an example. The serow ranges widely over the Asian continent. If it were to disappear from Indochina the species as a whole could survive. If the Saola disappears from this region it means global extinction. But there is an added twist: even in areas where Saola are present it appears to be much rarer than other ungulates. Again, because we know so little about the basic ecology of the species, it is unclear why densities are so low. Biologists speculate that the Saola may have lower reproductive output, longer generation times, and larger home ranges than other ungulates. Whatever the reason, species like serow and sambar are a dime a dozen compared to Saola. All this is to say that the species is naturally rare.

And that would be OK if the Annamite jungles were in a natural state. After all, the Saola has existed in these forests for some eight million years. But things aren’t what they used to be, and there’s no turning back the clock. Man-made threats have pushed this species to the edge. What are these threats? Let’s turn back to rhinos and tigers for a moment. The reason these species are in trouble is simple: they are targeted for the wildlife trade. Many people I have talked to assume that this is the case with the Saola. But actually Saola are rarely targeted by hunters—rather, they are caught as by-catch in snares set for other species. It is, in the words of Bill Robichaud, head of the Saola Working Group, very much a “tuna and dolphin” scenario. Saola are killed incidentally as poachers set snares for species that have high value on the local bushmeat or international wildlife markets. Saola are affected by the wildlife trade, but indirectly. In a way this is good news: hunters aren’t targeting the species as they do other mammals. However, a dead Saola is a dead Saola, no matter if the snare was intended for it or not. Just how severe is the threat from poaching? It’s difficult to overstate. In parts of Vietnam hundreds of snares can be found in a single day walking through the forest. Intensity in some areas probably reaches many thousands of snare-nights per square kilometer per year. And it is unlikely that there is anywhere in the Saola’s range that does not have snares capable of catching Saola. Put another way: there is no place that the Saola is safe. What do we do to mitigate these threats? How do we save the species? That is a topic for another post. In the meantime you, the reader, can help spread the word about the Saola. It isn’t as well known as rhinos or tigers. Let’s change that.

Saola poses for a camera trap
Saola poses for a camera trap in Pu Mat


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