I 
k 
March 17. Much like previous day, except for the fact that the 
gulls stayed on the hearth until 6:00 p.m. 
March 18. Unchanged 
March 19. First copulations, and Choking (low intensity) during 
feeding. Both Still rare. * 
March 20. 
The great 
The "best day so far; a great 
fight Between D and DD. 
deal of FB, Choking, etc 
March 21. Unchanged. 
March 22 and 23. Much as "before, "but gulls considerably less active 
Due to weather? * 
"THREAT BEHAVIOR" 015 GROUND . First impression. 
Erect. Definitely threat. Homologous with the Upright Threat 
Posture of the Herring Gull, Easily explained in terms of intention 
movements of attack and escape. Most aggressive form is with the 
Bill pointing strongly downward. 
HF and Bent Head . "Avoidance" movements, 
of turning and fleeing? 
Intention movements 
Anxiet y Posture ? Like E, But the neck is thin and the Bill is 
never pointed very strongly downward. Often combined with Bent 
Head and HF. 
• . 
Call and associated postures . The Upward seems to Be low 
intensity threat. Performed By Birds on ground when flying gulls 
approach only moderately close, etc. Not usually (Never?) the 
immediate preliminary of an actual attack. The Forward is also 
threat. Probably "contains" a greater intensity of Both attack 
and escape drives. In any case, the escape elements are more 
conspicuous than in the Upward. Indicated By submissive posture 
etc. * 
" Aggressive" Choking . Still a mystery, But a little clearer 
than last year. Derived elements are easier to identify. 
The. head down and the call come from the feeding of the female 
(sexual). (Are we justified in saying this? If the Choking seen 
during feeding is a complex of derived movements, these particular 
elements may have originally come from somewhere else.) The rapid 
opening and closing of the cloaca ( and tail exceptionally high?) 
