Flexible and Persistent Tool-using Strategies in Honey-gathering by Wild Chimpanzees

Tool selection can affect the success of a tool-based feeding task, and thus tool-using animals should select appropriate tools when processing foods. We performed a field experiment on Piak Nam Yai Island in Laem Son National Park, Thailand, to test whether Burmese long-tailed macaques ( Macaca fascicularis aurea ) selected stone tools according to food type. We baited the island's shores with stone sets (‘tool tests’) in an effort to attract macaques to use stones presented in a quasi-experimental design. Tool tests were placed at 344 locations for 126 days over a 2 year period, with each set containing four stones of different mass (categories: X, 40–60 g; S, 90–100 g; M, 150–200 g; and L, 400–1000 g). Tool tests were checked when we could access them. The number of times each tool test was checked varied (1–32), for a total of 1950 checks. We also studied 375 non-experimental stone tools that were found at naturally occurring tool-use sites. Our data were not collected by direct observation, but by inspecting stones after use. We found an association between stone mass and food type. In the tool tests, we found S-stones were chosen most often for attached oysters, and L-stones were chosen most often for unattached foods. L-stones were almost always chosen for larger unattached foods (greater than 3 cm length), while for smaller unattached foods (less than or equal to 3 cm length) selection was less skewed to L-stones and more evenly distributed between the M- and L-stone categories. In the non-experimental study, we found that mass varied significantly across five food categories (range: 16–5166 g). We reveal more detail on macaque stone tool mass than previous studies, showing that macaques select differing stone masses across a variety of tool-processed foods. Our study is the first step in investigating the behavioural and cognitive mechanisms that macaques are using during tool selection.

Section: Introductionmentioning

confidence: 99%

Long-tailed macaques select mass of stone tools according to food type

Gumert

Malaivijitnond

2013

“…Only chimpanzees appear to be able to use one type of raw material to make different kinds of tools, or to make one kind of tool from different raw materials. They use tool sets in a sequential order, make use of composite tools and combine tools to a single working unit [63,64]. In this context, chimpanzees as well as orangutans exhibit insightful problem-solving [65,66].…”

Section: (I) Tool Usementioning

confidence: 99%

Convergent evolution of complex brains and high intelligence

Roth

2015

One contribution of 16 to a discussion meeting issue 'Origin and evolution of the nervous system'. Within the animal kingdom, complex brains and high intelligence have evolved several to many times independently, e.g. among ecdysozoans in some groups of insects (e.g. blattoid, dipteran, hymenopteran taxa), among lophotrochozoans in octopodid molluscs, among vertebrates in teleosts (e.g. cichlids), corvid and psittacid birds, and cetaceans, elephants and primates. High levels of intelligence are invariantly bound to multimodal centres such as the mushroom bodies in insects, the vertical lobe in octopodids, the pallium in birds and the cerebral cortex in primates, all of which contain highly ordered associative neuronal networks. The driving forces for high intelligence may vary among the mentioned taxa, e.g. needs for spatial learning and foraging strategies in insects and cephalopods, for social learning in cichlids, instrumental learning and spatial orientation in birds and social as well as instrumental learning in primates.

“…Chimpanzees in the Taï forest are known to carry tools to nut-cracking sites even when those sites are out of view [43,44]. Chimpanzees in the Goualougo Triangle not only transport tools from one termite mound to another, but also further transport specific tools for specific tasks [45]. It seems likely that the chimpanzees plan ahead when selecting the appropriate tool for the task, even though that task is currently out of view [45,46].…”

Section: (B) Studies Of Great Apesmentioning

confidence: 99%

The future of future-oriented cognition in non-humans: theory and the empirical case of the great apes

Osvath

Martín-Ordás

2014

One of the most contested areas in the field of animal cognition is non-human future-oriented cognition. We critically examine key underlying assumptions in the debate, which is mainly preoccupied with certain dichotomous positions, the most prevalent being whether or not ‘real’ future orientation is uniquely human. We argue that future orientation is a theoretical construct threatening to lead research astray. Cognitive operations occur in the present moment and can be influenced only by prior causation and the environment, at the same time that most appear directed towards future outcomes. Regarding the current debate, future orientation becomes a question of where on various continua cognition becomes ‘truly’ future-oriented. We question both the assumption that episodic cognition is the most important process in future-oriented cognition and the assumption that future-oriented cognition is uniquely human. We review the studies on future-oriented cognition in the great apes to find little doubt that our closest relatives possess such ability. We conclude by urging that future-oriented cognition not be viewed as expression of some select set of skills. Instead, research into future-oriented cognition should be approached more like research into social and physical cognition.