IGS NeOleS =) ACU DB ON ABUL UE TIEN 17 
Auditory Cues in the Common Tern’’—the investigators empirically ascer- 
tained that Common Tern chicks greet their own parents by responding 
to the incoming parent's “fish-call.’” The same chicks cow when another 
chick’s parents announce their fishing success to nearby nestlings of the 
same species. 
Perhaps few persons are capable of the auditory range necessary to 
discern slight variations within a specie’s repertoire range. Maybe not. 
At any rate, by assuming that one can distinguish differences, the 
concentration to do so would most certainly enhance one’s chances of 
learning interspecific sound differences and the identification therefrom. 
References Cited 
Emlen, John T., Animal Behavior, ‘The Squeak Lure and Predator Mobbing 
in Wild Birds”, Volume 17 (1969), pp. 515-516. 
Greenewalt, Crawford H., Bird Song: Acoustics and Physiology, Smith- 
sonian Institution Press: Washigton, D.C. (1968). 
Armstrong, Edward A., A Study of Bird Song, Oxford University Press: 
London (1963). Lohrl, Stokes — both cited in Armstrong. 
Morse, Douglass H., Nature, “Territorial and Courtship Songs of Birds”, 
Volume 226 (May 16, 1970), pp. 659-661. 
Stevenson, J. G., Nature, “Individual Recognition by Auditory Cues in the 
Common Tern”, Volume 226 (May 9, 1970), pp. 562-563. 
A cardinal sang this morning. 
The ground 1s buried under a mantle of snow. 
A cardinal sang this morning. . 
Yesterday the groundhog foretold another six weeks of winter. 
The weatherman predicts a blizzard tomorrow. 
Bt hl vce | 
A cardinal sang this morning. 
It 1s so cold that cars will not start. 
Small chidlren must play inside. 
Men’s spirits are as bleak as the sktes. 
And yet, somewhere in a tree above my roof, 
A cardinal sang this morning! 
—Elsa Yaguchi 
Wheaton, Illinois 
—_ 
