The Sense Organs of Birds’ 
By R. J. Pumpurey, The Zoological Laboratory, Cambridge, England 
[With 4 Plates] 
Introduction 
Part of the interest and sympathy 
of man for birds undoubtedly arises 
from the sharing of similar worlds 
of sensory experience. Both birds 
and anthropoids, almost alone among 
animals, are excluded for practical 
purposes from the world of smell. 
“They haven’t got no noses, the fallen 
sons of Eve,” sang Quoodle. And he 
might have said the same of the de- 
scendants of Archaeorns. Birds and 
anthropoids are also almost alone in 
having both excellent sight by day 
and excellent hearing. Consequently 
it is easier, in some respects, for man 
to enter imaginatively into the life of 
a thrush than into the life of a dog, 
even though the latter is a closer 
cousin and the relationship has been 
enhanced by centuries of domesticity. 
This point is made at the outset 
because in what follows it will gener- 
ally be convenient to take the perfor- 
mance and structure of human sense 
organs as the yardstick of comparison. 
Each of us has a direct awareness of 
the excellence of his own sense organs 
and of the ways in which they can 
cheat him. So it is more informative 
to say that the eye of a buzzard equips 
him to recognize a mouse three times 
as far off as a man could hope to than 
to say that his visual acuity is 5. 
Such comparisons, however, empha- 
size differences rather than similarities, 
1 Reprinted by permission, with slight re- 
vision by the author, from The Ibis (the 
journal of the British Ornithological Union), 
vol. 90, April 1948. 
and they ought not to be allowed to 
obscure the over-all resemblance in 
the perceptual worlds of man and 
birds. 
It is true that much of the sensory 
equipment of all vertebrates is essen- 
tially similar. The senses of warmth 
and cold, of pressure and tension, of 
linear and angular acceleration, of 
taste, and of pain are all concerned 
in a greater or less degree with the 
complicated process of self-regula- 
tion necessary to maintain the organ- 
ism as a goingconcern. The mainte- 
nance of body temperature and of 
posture, the regulation of the heart 
and other viscera, the rejection of in- 
appropriate food and the avoidance 
of immediate injury are aspects of 
this process in which the part played 
by sense organs is fairly evident. And, 
so far as the task is broadly the same 
in all warm-blooded animals, it is 
scarcely surprising that the sensory 
equipment concerned with it conforms 
rather closely to a common type. 
Against this background the ‘“‘dis- 
tance receptors,”’ the organs of vision, 
of hearing, and of smelling, are con- 
spicuous for the changes which have 
occurred in them in the evolutionary 
history of the vertebrates. The vestib- 
ular (nonauditory) part of the ear, 
which is concerned exclusively with 
the appreciation of position and move- 
ment of the animal in space,? is vir- 
tually identical in structure in all 
2 It has been suggested by Ising that the 
vestibule of birds has an additional special 
function (see p. 326). 
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