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The first call I shall mention is one from which several others 
seem to be dif- f erentiated , i.e. feif develop* into the other 
calls at higher intensities. The call is a quiet "keeyer" 
and can be heard from birds fishing, from birds flying to and 
from fishing grounds, on migration, and numerous other weak 
situations of this kind. I name tnis call kyl . 
The first derivative of this cal^l is called^ ky2. It is a. shrill 
"ki tike 7 © ye r-ki tik/eye r-ke4ye r-ke f eye r-ki tike ey er " It 
is uttered on a number of occasions; by unmated birds who are 
trying to attract females, especially when they (the malesJ 
are carrying fish. In this situation it may be used on ohe ground 
.in the aerial advertising display. The same call is 
us ea *a*f ^er pair formation by a bird appraoching his territory 
gEXSRsjfcaii# or one who is carrying a fish, either for his mate 
or for the chicks. This call is also the usual one which can 
be heard from territorial disputes between neighbours, at 
any rate when the intensities of attack and escape are not too 
g-^rong. It is not often used against predators. xhe, form 
of this call is rather variable but is characterised by being 
polysyllabic and shrill. , , 
The next call ky3« follows the last one it an unmated bird 
is joined by a female. The shrill "ki tikeeyer" deepens to 
"i free y| r Veeyer yeryeryoryoryor . . . " This happens when an 
advertising male is joined by a female in the air $ fin the 
’’fish flight") or on the ground. In both situs tior^fche adopts 
the bent posture. The same call is also given by a bird while 
sera oinp- at nes t . rel&ief by a broody oird. In one of the 
hostile postures, the Crouch, in which attack and esepae seem 
most strongly activated the birds can sometimes be seen to be 
calling x softly and when I have been close wnough to hear 
this call it seems also to be this growly call, the Soft Call. 
Apart from this awkwarajmis call comes only in friendly situations. 
Another call presumably related to kyl is the loud "keyair" or 
"kairr" which is the usual call when you walk through and 
r retie tern colony. This cell, which is accompanied at higher 
intensities by wing raising, can be easily provoked by slightly 
alarming the birds. This is the call which you and Niko tnink 
is the tevnd Long Call. I remain as yet obtainately unconvinced 
about this. This call is fairly common among the Arctic terns 
as they go about their everyla^ Ilf e . Another tern often provokes 
it for example a f emaT^Jappraoching a male whom sne -oesn t 
know well, or ^ a brooder when an intruder approaches the nest. 
There is a. little evidence that a bird giving this call^is. 
aggressive as well as frightened but certainly fear is dominant. 
A weaker alarm call which doesn’ t grade into the "keyair is 
a short hard "jik" or "jekV This call can be heard in a great 
variety of situations; during fishing, flying to and from the 
fishing grounds, by birds on their territories ^ 
,vwv+v^r^ 0 -htir^ in response to a predator 
^ __ ). It also occurs 
during the ascent of the High Flight when it is uttered especially 
by the leading , i.e. pursued bird. 
