We are told that farming and dogs threaten Burmese long-tailed macaques’ use of stone tools to crack shellfish:
“Macaques easily change their feeding behaviour when influenced by humans, and we are concerned stone-using macaques will lose their traditional feeding behaviour if illegitimate development continues within the protected park,” said Assistant Professor Gumert, who is based at the Nanyang Technological University in Singapore.
On Piak Nam Yai Island, the team’s research site within the Laem Son National Park, they have found that human impact is altering the macaques and the island’s ecosystems. Of highest concern is the illegal development of rubber farms and oil palm plantations within the park that is clearing portions of forest. Humans are also competing with the macaques for food, by their harvesting of bivalves, such as clams and oysters, at the protected coasts.
Another major concern is harassment by domestic dogs that have been released to protect the farms. The dogs are repelling macaques from the shores, which inhibits their tool-using activity. As these macaques are forced to become more vigilant and to constantly keep a look out for dogs on the coast, they are paying less attention to learning tool-using patterns from their seniors.
“Traditions need safety and stability to properly develop, otherwise, the coasts just become a danger area that macaques must learn to avoid, rather than a stable learning ground for developing tool-use,” laments Dr Gumert.
“If these changes continue, the macaques could alter their foraging strategies, and potentially limit further development of their stone-using traditions in future generations,” stressed Dr Gumert.
Now, here at News, we’re on the macaques’ side. We think that conservation areas should be set aside and that in any event dogs should not be permitted to run at large—especially in areas where they are a recent introduction. That’s only common sense.
But the concern, as expressed in the piece, sounds deeply confused. Either bashing shellfish with stones is simply a foraging strategy that may not be needed if the macaques relocate to an area where they, say, dig or scavenge for their food. Or it is a strategy developed by intelligence. Which raises the title question, why don’t the macaques just throw the stones at the dogs?
Dr. Grumert clearly believes that tool use is a development of superior and possibly increasing intelligence (“they are paying less attention to learning tool-using patterns from their seniors,” “potentially limit further development of their stone-using traditions in future”). In that case, one might expect weaponry as a possible “development of their stone-using traditions.”
Especially when you consider that we also learn,
“These Burmese macaques are the only monkeys in Asia that use stone tools. Only two other primate species, out of several hundred in the world use stone tools — the chimpanzees in Africa and capuchin monkeys in South America. Knowing about primate stone tool use has important implications to compare with early hominine tool use, as well as the origins of cultural behaviour. Studying traditions allow us to investigate the cultural capacity of animals,” he added.
Well, primates do throw things, so perhaps this is a useful test: Can the macaque see that stones could be thrown at the dogs? To develop a culture, as opposed to simply a response to an environment, a life form needs precisely that sort of mental adaptability. Presumably, the early hominids had it. Fortunately, the macaque doesn’t really need that sort of mental adaptability to merit protection.