The table showing the frequency of postures in different 
situation has been arrived at without counts. I have not 
been too successful in attempts to count these things - we 
have tried it mainly in the Kittiwake - and I wonder in any 
case whether one would get much out of using other people's 
counts certain points are oovious aoout 
differences in intensity of postures and these one can 
described in words and I think that counts made by different 
people vrould only give one a false sense of certainty. 
PerhaoS I an too defeatist about these matters as I have not 
seen how you make use of your counts in comparing the 
motivation in different species. One of the points which worrie 
me is that, so far as I understand the method, it assumes 
that c dispute, sa.y on the communal area, jbaxxxHxxxBKiss 
•produce ? rousehly the same 7 ”inb ox motivations L oitus tion x** in 
pQ'j 02 pg i n a not we r . And X am not too c a in that this 
true for some of the s >ecies I have been lo king at 
f or 
are more 
g r ou nf 1 e s s 
^ne 
is — H ^ ir ! I 
instance Sandwich com >sredwitb Arctic Terns. In tnes- I * 3 * * * two 
species the difference in nesting density seems. to me perhaps 
to alter the motivation produced in the stock situations, 
likewise in the rr i t tiwake is it not possible that the proximity 
of nests on t cliffs means that c ris s of territorial 
encounters in this species with the 3 — n e ^ -■ e d G- cannot os 
mado very closely. In other soecies^where ecological conditions 
’ constant . I dare say that these objections are pnite 
g and one can -make* the comparisons without such 
drawbacks but I hope I make xy clear the reasons for my doubts. 
X look forward very much to seeing hov.’ you use yOur counts 
in " c paring e •eciea. fas it incidentally by means of the, 
that you oroduxed those wonderfully phallic diagrams locking 
■Hke p longitudinal section of an onion, describing the motiv&ti 
of posture! in to and 3ulU * * never heard 
how you accountedfor some of the intricacies of tnese f l^ur l ^ , 
'Whenever we have tried, we nave quic'xly enueu in some self 
contradiction eugiestinglthat there are more than two parameters 
involved. How many "simplifying assumptions" did you need 
to make ? I am not trying to be funny but we are genuinely 
interested to know how y~u have extricated your del f from 
the sort of motivational impasse wnich we foum ourotvlvec 
led into . 
ITiko is due back in a week and then I shall perhaps 
see your new reoorts about the Inca Temet al. l wonder 
very much how. they fit in with the ideas which I have come to. 
on 
two 
I am still stuck to find this in the Arctic though there are 
xstxaxxi possibilities. The trouble seems to be that tne^ 
terns - at least those s jecies I hr ve looked at ~ ~or\ t ^ 
attach by oe eking downwards and one would not expect to una 
an aggressive upright funless it is a relict from a- ancestor). 
/II the species I know attack by a horizontal eck so iar as 
I can see. Any ideas ? 
* tk 4Wyt UM* 
