,i ' 4 ■ 
I have iaontionetl earlier that a tale! recognises a feoe&s's intention to 
land cm Ms nest but if "a hint prepares to land on a neat in the imiadiate 
vicinity of m mwmt&d. molo ha say isisjta!®- it and ktttiwake loudly towards 
it as if it ware a visiting fesiale. Butt as. soon as he understands to® other 
bird’s true iatcnfcim Ms calling stops abruptly aarl fas follows the ♦•dexjeiifUT'' 
aniiaal with Ids eyes* very quickly, however, rmigbbewre loam to knew? one 
^aiottor iirUvilually and do not leeks adstaleas each ot i*er for visiting fsaslM 
any laws* Ouch junolteits are sn&nfQl ^wtwiitiss for f cl lowing the biiMh 
ug> of personal ;relatioo*ss&o® between Son® exar^les of these social 
relatiorisliioa are cited, later. 
_\]V» 
V 
Kji 
w 
^ > visits Mti. 
^ ' posture 
tongue 
on a ledge 
Said bow or 
This imm 
val m n . 
said that a saale reacts In a special way towards a f stasis tste 
IHnniids atlasr birds, especially rival sales, he reacts by another 
/rah and Bow (Fig* 5). in the choking tbe neuth is open, the 
®> spooled. call., tiie Meta, uttered, Birds she try to lend 
sore oft< lefleoted away in the air when a neigjbbour starts to ®roh 
birds alrealy alights aay take wing again as a reaction to it. 
tlie posture fri|;5iteiis or in other words that it has a "threat 
%yk 
d ,\f <7 
#1 
;o far only the function of sobs of the displays has boon mentioned but 
mi also vjant to knew what jgiaa ep the birds to show one pasture rather tlasn 
another. In see cases, bbT&t instance in the /rah anti Bow, it is not so 
difficult to assess the underlying drives. A bird so displaying often goes 
over to attaokldg an opponent but in saae oircnstetances he say flee. Further 
ho oay show the intention of attacking and ©soaping alternately in tuink 
succession* ^'raa this and other evidence one can oofsoluie that in on arch- 
m^l-ixrciknQ bird attack and escape tendencies are awake MwMtaneoualy* If 
only one of the two drives me activated the bird would not display but act 
iiaa@di4Etfc@Iy, it would either attack car escape. Ti*© autual interaction of the 
two gWes arise to tsplay. 
To analyse the choking display ia this may is sore difficult. I Ijsvo to 
moatim that the aaro choking (fig.1) which ©akaa up the csAs's song is also 
dimm during oppressive ©ikjou iters between rivals. Like the urch and bow it 
mm lead to attack or oscaw. For the same reasons w© can presume that ttm 
attack and escape dries© are both aotivt . can wo now »ppes© that the Poking 
of the sale at flying birds and the Eoutual c&okiRg down of the pair ia 
ijreetiag lias the mm® notivation? Let us first deal with the males of his 
0 $ pamivemm towards the fsimle we see emm^i signs* His escape tendency 
also ^Ixjcoces ay nasront but only uncUw special oimsn^tanoea, bit then it is 
Uivalstakoabls. Attack and ecoepe drives ac©ia to b© aroused in hiui. d'io Female 
on tine other hand sl.w© lwr eeoape temlenoy clearly by fleeing. Hr f act 
tiiat under exceptions! ooodltioas, iwwver t ahe ssay attack the ^ale gives 
evi desiQO of her o.^grseMvwnsss« One Mght esrpeot that ilia sex drive ixust also 
be active in picking because oh^dng iu used in tiie mutual greeting and becauoe 
in tiie song It attracts Hie f swale. But since choking occurs also in f ights 
tida is olearly not a neoessary condition. The song of a masher of species of 
birds, wriilo attracting a feKsds, eeeoe to be {activated by a certain m ount of 
a# 'greseivaness and it is an eeswessioa of the fonale* sex drxvo that aJ^e 
