JPMugus 1979 Tryingito subtruficollis Tower Llanos, Estancia Wedeland, Atibildes 35 Kms. of Juancho by road, Ptdo de Madariaga, Pcia de Buenos Aires, Argentina 23 January (cont'd) (0751-0851) I recorded 25 discrete acts of aggression involving K. All of them K was the aggressor. It appeared to us that there were 2 types of aggression - that against neighbors, a subtler interaction except during those times in which fighting occurred. I.e. the interactions are of 2 extremes. The subjects all forma were either tail-dragging (Huinack feeling I described before) or neck-rising. Perhaps croching occurred without any fights, but it was certainly more common with fights. Preening + resting on my also occur soon an aerial fight, but it is difficult to tell when these 2 activities occur whether or not they are some form of information, unless it is in the context of a fight + croching. Fighting was unmistakable, entailing hopping, wing waving + jabbing, interposed deliveries both of fighting is croching, + sometimes tail dragging. The latter particularly when one of the 2 is still croching. - the second type is that between territorial birds + "foreign invaders" - this typically begins with a wing flash as the foreigner flies by or in. Sometimes that suffices (the $ intruder does not land, or takes off in media- tely). We do see wing flashes sometimes without knowing to whom they are directed. If the intruder remains, the resident either runs or flies (usually the latter, no matter what the distance). Flight is peculiar, often in sideways (independent of wind) - similar to heli helicopter flight. Legs down, body not only sideways but 60 to 30 degrees off horizontal. [illegible] - neck + legs outstretched. Resident lands near intruder. By then, the intruder is usually either flying or running away. Resident follows it to decisive boundary, running with a stiff neck. Vocalizations during flight + run- ning. Chase can continue off territory, but this frequently degenerates into an intimate with neighboring bird. If the intruder does not fly, there is an in-flight airborne fight. (back to K-) K's area territory was of approx 12 units, or 300 sq.m. One area was used most continuously, viz (2,3), (3,4) 25 out of 60 minutes. Border fights were most intense in the (2,0), (2,1) (3,1) area. K also had a definite boundary in (3,4) See p 63 Grid book