10 . 
Aggression during or after feeding (M, Mar 26, 6-7; 
R. Mar 24, 5; R. Mar 25, 1-2-4; R. Mar 26, 5; R. Mar 27, 2). 
Copulation * Incomplete (R. Mar 26, 6). 
Nest-building . First signs (M. Mar 26, 5; R. Mar 26, 4-7). 
Then some extensive nest-building (M. Mar 27). Quite complete 
pattern. Male taking initiative. Several nest-sites. 
" Aggressive 11 Choking . "Aggressive" Choking has been commonly 
observed every day. Always certainly threat, with one possible 
exception (M. Mar 26, 5). A clear and typical "aggressive" example 
(M. Mar 26, 2). Sketch of possible difference between Choking 
and Scraping Postures (M. Mar 27. 18). The male of a pair sometimes 
pecks the female during Choking (R. Mar 26, 3). Does the fact that 
the male "Kroons" in boundary- Choking explain why the female 
sometimes FB during such disputes? (M. Mar 26, 8). 
It is possible that males sometimes Choke on returning alone 
from Circular Flights (M. Mar 26, 2). 
Head-flagging . To flying birds (M. Mar 25, 3-7). Toward an± 
opponent IM. Mar §7, 14-17). 
Forward . The E posture changes immediately into an F when 
the .opponent suddenly flies away (R. Mar 24, 4). 
