Intelligence in Nature - Jeremy Narby [73]
CHAPTER 4
P. 41: CHIMPANZEES WITH CULTURE
Whiten and Boesch (2001) write: âHumankindâs nearest relative is even closer than we thought: chimpanzees display remarkable behaviors that can only be described as social customs passed on from generation to generationâ¦During the past two years, an unprecedented scientific collaboration, involving every major research group studying chimpanzees, has documented a multitude of distinct cultural patterns extending across Africa, in actions ranging from the animalsâ use of tools to their forms of communication and social customs. This emerging picture of chimpanzees not only affects how we think of these amazing creatures but also alters human beingsâ conception of our own uniqueness and hints at very ancient foundations for humankindâs extraordinary capacity for cultureâ (pp. 49, 50â51).
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P. 42: DOLPHINS RECOGNIZE THEMSELVES IN MIRRORS
In an experiment conducted by Reiss and Marino (2001), two bottlenose dolphins living in captivity in the New York Aquarium were marked in black ink on parts of their bodies that they cannot usually see. They were also âsham-markedâ with water rather than ink. Both dolphins were accustomed to living in a tank equipped with a mirror. In separate trials, each animal repeatedly swam straight to the mirror to investigate the place where it had been marked, often twisting and turning to expose the proper spot, on the underbelly, above the pectoral fin or behind the ear. They also spent considerably more time examining marked places than sham-marked ones. And they showed no interest in marks on other dolphins. Until recently, scientists thought that only great apes and humans could recognize themselves in mirrors. This ability, which is considered to be a sign of self-awareness, was thought to be an exclusivity of âhigher primates.â But these dolphins, who last shared a common ancestor with us 70 million years ago, seem to have developed self-awareness on their own.
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P. 42: CROWS BUILD STANDARDIZED TOOLS
Hunt (1996) reported that a breed of small crows living in South Pacific rain forests manufacture tools with standardized hooks and toothed probes to help in their search for worms and insects hidden in holes. To make a hooked tool, the crows use their beaks to nip twigs away from a branch just at the point of intersection with another twig. When done carefully, this creates a small hook at the base of the twig. Hunt writes: âCrow tool manufacture had three features new to tool use in free-living nonhumans, and that only first appeared in early human tool-using cultures after the Lower Paleolithic: a high degree of standardization, distinctly discrete tool types with definite imposition of form in tool shaping, and the use of hooksâ (p. 251). Hunt comments on his research: âThere are many intriguing questions that remain to be answered about crowsâ tool behavior. Most important would be whether or not they mostly learn or genetically inherit the know-how to make and use tools. Without knowing that it is difficult to say anything about their intelligence, although one could guess that these crows have the capability to be as clever as crows in generalâ (quoted in Davies 2002: 2â3).
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P. 42: VAMPIRE BATS SHARE FOOD
See Wilkinson (1984). Kennedy (2002) says: âVampire bats nest in colonial roosts, and they go out at night hunting for prey. A sleeping dog, or livestock, or a beautiful woman. And itâs quite obvious that this kind of predation doesnât always meet with success. I mean you donât find a sleeping dog just everywhere. Sometimes some bats score and other bats donât score. And a zoologist has studied now quite carefully the behavior of vampires who have been individually banded, so they can be distinguished as individuals within the colony, and watched them over long periods of time. And what turns out is that vampire bats, when they come home with a large blood meal, are apt to share it around. Thereâs more than I can use, so please have someâyou