• cthod of be oOf>; 
n of* Isid.ivM.ual3, 
.iit.'i.i. 8«*iia praotioe it is y oa dfc lt to reostjaiss the individuals of t. 
JciifcitfaJx aolony by ths bleak lacrka m tl* 6th prJtoary. figure 6 a* sow* 
..tfSirea rib 
, Duel* gradual abases tfcr«*gfc series of adjacent feathers are ootmm 
■ a* i ctPRttrvQd la ,’t* 
04." the :.40,J,/ ml oar* affect any different p rop e rt ies of tie feathers apart 
row ti ana s oar* prop .UPf— 
*ig*7 where tie dark area decreases 
**«*» tJ>c 4th prisny on either aide, 'fhe greatest variability 1 b found 
the |44ie«aUtioa tails off. !3il* is also Biaora in Pig»7 t Uhe pattern 
7 la the . ; i • a rmim .x; : . .■■■■:* 
e 
■ 
of tho ipi t, s tm for instance, the herring and bleaS-Jaoaea rull®, the 
■ -' v ' fur ok in the roar of that the 
. 
fiaitivW fortunate oh&noe is that the pattern, hmmv&F vf a*4ahie free an© 
iitliirMu & to another, ?.s fairly fli»3 in fciic sane individual and across out 
7&a abl . follow 
Ub old jahahltaarte of' ej colony right ilsrcrngh tie mat la the suturro. 
i^^oesalve patterns sir© shorn ou *ts.S. The wing feathers are only 
eioultod onoo a year by the adults, in cutunn, and abrasion hardly affects the 
--.ec e 4 i fear weeks before the feathers drop out, althou^ the light 
oro&ii yfoicli rare less resistant Ueeorae * 
•* * Wfc* 
« 4 * 
3he**e t*sre, Soever, indiTMuol s with patterns i&loh I oanl3 not distinguish 
rrota*Uieh other out mostly I was able to Seep them apart "by dlffa^enoes in 
oa.i/r siisraotasps such as beak or log colour, or by mice or behaviour, all 
raiste on am i ?«r .he not To give an idea of 
toeharicur&X peed hri tie s t sight sKntiosi the attaoirrr.nt of a ■ md to 
,tiia aeii^eur* & ftaale, the building. of a gigantic nest or aa unusual rhytiai 
m one ©r ux oaixi 
: ’f ‘4’a.lji,’ all the different inffiydklual clssraciar© there viai lit ' lc -roubt 
about 4 so Mensliy of eg birds tlAXWg^i the season and in tr.e su3oa»3ive goers, 
hut sis'm so xoi.j;„ of m study has Surood on the xmsofg&titm of individw^lja 
f hoy® to tsabwUlato furtlwr evhlc.iec nest year on the oonataiiuy of 
workings sad other oharao-ters. 
■eg 
: fiiok ieuox)it:oa. 
j w%. ‘^rw*-. - - , .gft'r « v .> 
; .»•-. -W/v/V - 
a 1 
a.*. 
ihoergen. found by experiirost 'that hwsrtog grills da not reoo^lie 
the-ix* owa ,in the fi^gday® of the kick’s life. \:h j onl,, learn to 
V x- .^i. v jfc V •• *'C ,'. 
4 pir 
ee, ijtUvids 
4 .y- 
-S>x ® 
f-u a. v 
£•*« Si 
w)ear ot rraia 
p - 
%4 *1 
1 j** 
5 days, 'ait they rx*/er lesra to hi <^inguisl'i 
i^hoars. eaisotlaes oulte a different 
■ I I reoogjaian tlie looelity of their mat ©it». These tsao 
typea of rooo.jiition are well adapted to the beliariour of eg b and chicks s 
the sggs moBia. in the nest hut the chio3tes: socss stm-d, to run" about. Tlse 
X^eoaonal recognition guarantees that the parents food their own youiig. jf 
one assumes that tl*© pajwits learn to recognise tine eliioks for this purpose. 
