In what appears to be a scene from Kung Fu Panda or an Animal Planet horror film, scientists conducting research in Perak discovered that a kind of monkey had been dining… on rats. So, according to an article published in Current Biology, a group of scientists doing research in Perak’s Segari Melintang Forest Reserve and the neighboring oil palm fields spotted two groups of monkeys. These monkeys, known as Southern pig-tailed macaques, are similar to what the locals call beruk. They are typically jungle inhabitants in Malaysia and Indonesia but have recently found their home on plantations.
However, our Malaysian hospitality is not extended to them, as palm oil growers see them as pests. This is mainly due to the fact that the monkeys devour the oil palm fruit. However, the monkeys, like a drunk vegan, have a desire for meat as well. While the monkeys did spend around 3 hours a day at the plantations looking for food and eating, it appears that they were not eating solely oil palm fruits while they were there, as they were seen chomping on rodents.
This contradicts popular belief about the diet of the Southern pig-tailed macaque, which was previously supposed to consist mostly of fruits, berries, seeds, fungus, and invertebrates (aka not rats). In fact, the monkeys not only got rats as a treat, but they were near enough to be their main food. According to the study, one group of pig-tailed macaques ate an incredible 3135 rats in just one year. Given that a group of macaques typically consists of 15 to 40 monkeys, this means that just one of these monkeys might consume up to 200 rats every year!
However, it wasn’t until the researchers discovered these rat-eating monkeys that they realized it may be a beneficial thing… Remember what we mentioned about oil palm growers treating Southern pig-tailed macaques as pests? It turns out that these same monkeys might have been assisting oil palm farms all along by hu.nt.ing out rodents. While monkeys do consume oil palm fruit, this barely affects 0.56 percent of the plantations. When compared to the 10% crop damage caused by rats, the researchers realized that having monkeys surrounding oil palm farms might not be such a bad idea after all.
The approximately 3000 rats that a group of macaques k.ills in a year account for three-quarters of the rat population, which means that crop damage from rats may be reduced to just under 3% every year, thereby helping oil palm farms acquire an extra USD650 MILLION, or around RM2.7 BILLION! Unfortunately, the International Union for Conservation of Nature categorized pig-tailed macaques as a vulnerable species in 2008 owing to poaching and habitat degradation such as deforestation.
The researchers also stated that the macaque population has most likely declined much further since then. They now believe that, given the finding of these monkeys’ potential value to oil palm farms, they may find a method to create a win-win situation for both the primates and the growers.