JPMayers 1974 Journal (1321) Estancia Midland, 35 Km S. of Franco ley road, Pueblo de Madariaga, Provincia de Bs. Aires, Argentina 9 November (cont'd) I watched only a 50 x 50 m sub-portion, but censuses during that period showed too few birds were included, so I expanded the area of focus. From 0640 - 0810 I merely censused the area, familiarizing myself with the local terrain, the birds, and at the same time recording all instances of space-specific aggression (e.g. to form, location and behaviour). From 0810 to 0940, 10 minute censuses were broken down into two groups - total buffin and the number of these showing space-specific aggression (i.e. territorial). Lots of s-s. aggression was contained. See buffin sp. accent: An average of 47% of birds present on the grid during each census were territorial. Numbers were small, ranging from 2-7 total and 1-2 territorial. Three territories camped upon the grid, one of which lay almost entirely within, and occupied an amazingly ~1550 m² Frequency of aggression dropped sharply as the morning went on, at least partially because during the early hours several (at least 2) buffins were behaving territorially in an area which later was used only by a directional flock. After completing the % territorial calculation, I tried unsuccessfully to collect the Tryngite which had occupied the large central territory (bird increased during the morning from 0 cipre dawn to with a light E breeze, clouds a constant 0. Low mist which burned off by 0630 Grid 15 (9,18) region, Estancia Midland, Pueblo de Madariaga, Provincia de Bs. Aires, Argentina 10 November began a sample of Grid 15 at 0650 - light E wind, t = 18°C, clouds 30%, the cloud cover all on the southern horizon was sufficiently similar to previous formations which had resulted in afternoon thunder showers for me to make that prediction at dawn - high and continuous cumulus hanging far to the east. Sweat coincided with high early morning temperature. On the grid, shoulder bird density seemed showed a disturbing drop, not only in Tryngite but also Pluvialis total: Tryngite subcorcollis 54 (see chart = 1.22); Pluvialis dominica 109 (see chart = 1.04). Vanellus chilensis 5; Sprolyto curicularia 2. Two possible explanations for the decline in migrant %s: first, on our way to the grid, we saw large flock of Tryngite, totaling well over 100 birds, in the (4,9) - (5,14) region. This flock had been building but today the numbers were remarkable. This area lies between the (1,8) region where Grid 15 is, and the known Tryngite roosts. Secondly,