LEARNING AMONG BIRDS
bgold at itsa.ucsf.edu
Wed Feb 14 12:01:24 EST 1996
LEARNING AMONG BIRDS
As a taunt among children, 'Bird Brain' has a pejorative sense.
And well it should!
For it denotes the dimished complexity, the smaller information capacity,
the very simplicity of the avian neocortex as compared with our own.
And yet it is from persevering in studies of simpler living systems
Crick (1) instructs, we may more deeply understand the sources
of memory, thought and consciousness itself.
I recall a photograph of the great austrian ethologist,
walking booted through a verdant pasture,
several ducks squabbling close behind,
having imprinted themselves upon him,
believing Lorenz to be their mother,
from a critical moment in their lives.
But what feels more striking for me are the ideas about mimetic
learning that Arthur Koestler used to present (2).
This story was told before a 1956 meeting of the Linnean Society in London
by Hardy: Some years earlier, some thirsty blue-tits had noticed
bottles a milkman left on a London doorstep containing
a puzzling white liquid. These ingenious birds discovered a way of
getting at it by removing gthe tops of the bottles with their beaks.
Apparently, they enjoyed the liquid because the birds learned to deal
with cardboard tops, and soon also with metal tops. The new skill
soon spread, apparently by imitation 'all through the tit population
Hardy went on to suggest that a progression similar to beak
evolution in Darwin's finches could result from
further reinforcing British milk bottle armature.
That is, given sufficient time and selection pressure.
Imitative behavior among birds, Hardy concluded, could form
a microcosm for human 'cultural evolution'. As such it was dubbed
'The Baldwin Effect' after its arcane, turn-of-the-century discoverer.
I will not defend Koestler, Hardy, Waddington or Baldwin:
Each of these espoused ideas in order that they might
strengthen their own unique theories of cultural evolution.
Rather, I choose to remember 'The Baldwin Effect'
as I try to understand the startling discoveries of
the last few weeks: That on occasion, crows use tools!
The discovery is all the more remarkable because it was
the result of almost wholly self-financed expeditions to
New Caledonia, by a New Zealander, Gavin Hunt.
Hunt writes (4) that in making two kinds of tools, a hooked twig
and a jagged edged chisel, his crows were ble to scavenge prey
under forest detritus, that otherwise would have been forsaken.
Prey here is presumably one or more varieties of local insect,
made more suceptible to the crow's palate by use of its tools.
So now we know tools are of birds, apes and men. And that we have
lost our claim to uniqueness in this respect. And although one
author (5) makes efforts to diminish the significance of the finding;
implying that the crows lack 'imagination' in creating these
rough hewn devices; for me he does not succeed.
Perhaps because I never pretended that I thoroughly understood
the muse that gives rise to imagination on this green earth.
(1) Crick, F.; The Astonishing Hypothesis, The Scientific Search for
the Soul; New York, Charles Scribner's Sons, 1994, p. 20-22.
(2) Koestler, A.; The Ghost in the Machine; New York, Danube Edition,
Random House, 1976, p. 153-154.
(3) Hardy, A.; The Living Stream; New York, Harper and Row, 1965, p. 170.
(4) Hunt, G.R. (1996) Manufacture and use of hook-tools by New Caledonian
crows, Nature 379, 249-251.
(5) Boesch, C. (1996) The question of culture, Nature 379, 207-208.
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