'Armed' chimps go wild for honey

By Rebecca Morelle

Science reporter, BBC News

Cameras have revealed how "armed" chimpanzees raid beehives to gorge on sweet honey.

Scientists in the Republic of Congo found that the wild primates crafted large clubs from branches to pound the nests until they broke open.

The team said some chimps would also use a "toolkit" of different wooden implements in a bid to access the honey and satisfy their sweet tooth.

The study is published in the International Journal of Primatology.

Crickette Sanz, from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, said: "The nutritional returns don't seem to be that great.

"But their excitement when they've succeeded is incredible, you can see how much they are enjoying tasting the honey."

Honey monsters

Chimps' love of honey and their ingenuity at accessing it are well known amongst primatologists - previous studies have revealed how the great apes can fashion sticks to dip into or prise open nests. The chimps will go up there and hang at all sorts of precarious angles to get to the honey

Crickette Sanz

But until now, nobody realised how prevalent the beehive-bashing behaviour was amongst chimpanzees in the Goualougo Triangle in the Congo Basin.

Dr Sanz said: "It seems these chimps in central Africa have developed more sophisticated techniques for getting at the honey than populations in eastern and western Africa - maybe it is some kind of regional feature."

Perhaps for obvious reasons, the chimps avoided bee species that sting, targeting the hives of stingless bees instead.
The chimps can spend hours trying to access the honey

Dr Sanz told the BBC: "But these nests are tough to get into - they can be at the top of the forest canopy, at the end of a branch - and the chimps will go up there and hang at all sorts of precarious angles to get to the honey, using these clubs in any way that they can to access it."

The video footage, which was filmed by the researchers over four years, revealed the chimps' sheer determination to get at the sweet stuff.

Dr Sanz explained: "Nobody knew they would pound over 1,000 times to get to the honey.

"Sometimes it could take several hours - they would start in the morning at around 1000, then take some rests, and then finish up at about 1400 or 1500 in the afternoon.

"It is quite physically challenging - in the videos you can see how large those pounding clubs are - some weigh over a kilogram."


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Success at last - the researchers say the chimps have a real sweet tooth

The primatologists also found that the Congo chimps' tool use was more sophisticated than previously thought.

David Morgan, a co-author on the study from the Wildlife Conservation Society and Chicago's Lincoln Park Zoo, said: "One of the most exciting aspects is that they are using multiple tools to access the honey that is in these hives.

"They have a tool kit ready when they go for honey.


Chimps craft ultimate fishing rod

"They will have large pounding clubs and they'll use those to hammer the hives.

"And if that doesn't do, if the holes are too small, then they'll access them using smaller, thinner dipping wands. And they are also using smaller sticks for leverage to get better access to the hive."

The researchers also said that once the chimps had spotted and then crafted a suitable club from a branch, by pulling off unwanted twigs and leaves with their teeth or hands, they would set it aside for later use.

Dr Morgan said: "They cache them in the canopy."

Last week, the same team also reported how Goualougo Triangle chimps were crafting fishing rods with a brush-tipped end to fish for termites, and the scientists say there is still much to learn about tool use in these chimps.

However, they told the BBC that the chimps' future was uncertain, as the primates and their habitat were under threat.

Dr Morgan said: "These beehives are found in tree species that are exploited for logging, so this could be a direct affect we have on their behaviour, their feeding and their conservation."