Chimpanzees prefer termites as a seasonal delicacy

California (ANI): The finding that chimpanzees use tools to catch termites changed our understanding of their talent — but we still need to better understand termite fishing and the brains of chimpanzees. Important context is required.
The relationship between termite availability and chimpanzee fishing was explored by researchers at the University of California Santa Cruz (UCSC) and University College London (UCL). They found that termites are most available at the beginning of the wet season. Despite the abundance of alternative foods at that time, chimpanzees preferred termite fish.

“I believe these results establish an interesting hypothesis about wild chimpanzees,” said Dr. Vicky Olez, UCSC, senior author of the study in Frontiers in Ecology and Evolution. “Although we can never read the thoughts of chimpanzees, we can perhaps begin to get an idea of their expectations of resource availability by analyzing instances in which they approach termite mounds and probe them for the feasibility of fishing.” We do.”
Termites are a major source of nutrients for chimpanzees – but the chimpanzee species prefers to live within fortress-like mounds. However, some termites will disperse to start a new colony elsewhere, and will leave the mound through the flight holes that chimpanzee termites use to catch fish. In some places, chimpanzees fish all year round: in other places, fishing is seasonal.

Understanding the availability of termites is important to understand variation in the use of fishing tools by chimpanzees. Does tool use vary between chimpanzee populations because opportunities differ, because needs differ, or because tool use is unlikely to have been invented or maintained? To understand predators we must understand the prey.

The scientists focused on the Issa Valley, Tanzania, which has very distinct wet and dry seasons. The researchers collected years of meteorological data and camera trap footage from 13 mounds to map the spread and predation of termites over time. They also conducted termite-fishing trials on 14 mounds between 2018 and 2022, mimicking chimpanzee tools and techniques.

“When I first visited Issa Valley, I quickly learned that saving fish from termites was much more difficult than I expected,” said corresponding author Seth Phillips of UCSC. “This alerted me to the idea that finding effective bait for these termites may be more complex than people commonly realize.”

Out of 1,924 attempts to catch termites, termites were removed in 363. The scientists found that as rainfall increased, they were more likely to be able to remove termites – until 200 mm of rain had fallen. Then the proportion of successful tests fell. Most termite mounds were most active between 50–200 mm of cumulative rainfall. Dispersal flights occurred only in the wet season and stopped almost completely after 400 mm of rain.

“We are currently reviewing camera trap footage of chimpanzee behavior at these dunes,” Phillips said. “We want to know how chimpanzees adapt their searching behavior to seasonal changes. For example, do they check for termite mounds after a long drought followed by straight rains? This data may say something interesting about their search cognitions related to tool-use. ,

Chimpanzees were among the most frequently recorded hunters on termite mounds during dispersal flights and often brought a tool. In the Issa Valley at this time of year, other food is available: chimpanzees use tools to pluck fish and termites because they can, not because they need to.

Although some chimpanzee communities exploit termites throughout the year, including in the relatively nearby Gombe Stream, termite fishing there also peaks in the early wet season. Some year-round fishermen may benefit from softer soils or a more effective toolset. It is unclear whether more sophisticated equipment will allow continued exploitation of termite mounds in the Issa Valley, but preliminary tests suggest otherwise.

“After all, we are human experimenters attempting to replicate chimpanzee behavior,” Phillips cautioned. “It should not be taken lightly, for example, that we are as effective at foraging for termites with these tools as chimpanzees. “I hope that the opportunity for termite fishing for chimpanzees in the Issa Valley is at least a little as extensive as it is for human researchers.” (ANI)