Having established that thorn la t general increase In bath 
the nuaber of awooi attack® and In the broodinee® duping 
Incubation I suet neat firH if it la ?sslble to correlate 
variation in one with variation in toe other* For ex;,»ple 
1® It true that the bird# which breed moat steadfastly 
ere those which at trek neat vigorously ? X nave the neoea^ary 
date but the as yals Is not yat finished*' 
. - ; _ -* . - * * ' %. * . v . * 1 
Another nrobleit I have a tar tad on is uro ther there 
la on ? kind of aggras sivenesa for predators and another for 
ot‘-«er terns. To do this It is necessary to .. t .y very carefully 
the dlatnace fro» the nest which treats® alng terns were able to 
reach before releasing various tore. t noctures in t 10 sitting 
bird and how c they could cone before they were itaelred* 
m nest where this w lone on. more t n a li ■. ry 
scale enough data were collected t show anise of recta, such aa 
thrt the nnle ’.voul d reoct at & greater di trance t > X o trade r a 
then the fwaale. It was also id that the -raWotion . 1 t oe 
of a bird was inch greeter If it ware standing by the eggs than 
if it were sitting on the nest. Actual brooding as or. a to inhibit 
aggressiveness , not only in or even ting attacks but ®-»o in 
preventing toe bird uttering a*- resalve oc d threat 
postures. If this Is true, and It was not un© < -acted* toe 
sorrel a ties between $ip inesa and aggreaaiveneaa la not 
. n lie re «• m g* < -* 1 
te-o to fluctuate together over a tier of d* ya, over r fe o 
minute they raey be inversely corral* to > • Tni in lie tea one 
of the cor- oil cation® which t r y upset the elaple icture and 
it la just such compiles tiens Which cause trie groat variability 
in result® and oa v e the establishing of true rcu tionuUi .-r 
such b. long an ’ difficult te- ak . , 
On® of the disadvantage® of field studies is 1. 1 © shortness 
of the season. As the ? hole colony iciausa first into toe courts hi 
phase and then to egg laying end finally to rearin'-, y gth© 
orobletsa which on® c ; n te-C'l© a i®o auc eed one t nottur • /ne ss* 
cannot concentre* te on one aspect of th r© .-reductive behavior 
for th 5 whole season. After a few tent; tiv ■-.? uoginninga at 
analysis of toe relation between aggrearivene-JS and broodiries® 
the If it eggs are hatched and on© is sweat on into the pel*- tic ie 
between *a rente* end young. 
Th«, fee ’lng of too young was of ,.>srticul* r interest as-, it 
.vlSn«riiiU amrtt - * < W for the &rent* to find 
fish and easy of the you on the beach di i* Thera was intense 
food cor: petition between too young and the li ter hatched one® 
were robbed again rrr - * ag?ln by their co-. vnlons until too,, *-• a®u 
,v; ;ifK , • t. i*r* W* wrdxy 
any carte 1 i ty at all. In IM1 the e«i of toe season was t-»lnly 
devoted to watching one chick and hi® brother and their 
hehsvi if with on© another* with their « rents and with ot; .er 
adulte and young. Curiously enough there were tor. r ’ 
e ehlakc. t ilr ■ o <■ tote. ; ' - ' r m 1 ;i ‘ 
eerllect day® end wa 
Ir*. *v;owe i an interest in «- **'■«•» 
robably the ease indlvi iu l who had 
