JPMyers 1974 Journal Grid 15, (0,18) region, Estancia Medaland, 35 km S. of Juancho by road, Ptdo de Madariaga, Peia de Bs. Aires Arg. 19 October (cont'd) The table shows almost a 40 fold difference between mean buffle densities. However golden density varies only 2 fold. The graph below, showing the relationship between X-bar sub 6 and X-bar sub 7, reveals a strong positive correlation between the two variables. This could be a result of a number of factors: 1) both birds/habitat could be distributed similarly, as is certainly the case. (but why the vast difference in ranges?) 2) one species may be attracted by the presence of the other (prob. true, but not always, or at least not simply, because there is golden -> buffle aggression and supplementary. 3) some factor could be keeping both birds out of some areas, but operating more heavily on buffle. this is certainly true to some extent -> Vanellus chaeas both birds out of the vicinity of nests + foraging chicks. Sprotylo causes buffle + sometimes golden to speak. Thus, if we make the following table: subunits with - i.e., 1,2,3,9,10 subunits Sprotylo, incubating Vanellus, or Vanellus chilin malky without i.e. 4,5,6,7,8,11 X-bar sub 6 #golden 11.6 (7-14.5) 13.3 (9.8-15.3) X-bar sub 7 #buffle 3.0 (0.7-10.1) 24.8 (12.8-36.8) Although I don't have the means here to test for significance, it is apparent obvious that those sub- units without Vanellus incubating (or with chicks) and that for Sprotylo have greater densities of both buffle and golden. Buffle densities vary much more than do golden densities. While this table shows a strong effect, I also suspect that habitat differences are also operating. The trio of subunits 1,2,3 are all a bit Varae thicker in vegetation, possessing Distachlis instead of the Tripliium tual. association dominating the grid. This factor should reveal itself when we take habitat measurements. Linear grid, Arroyo Chico, Estancia Medaland, Ptdo de Madariaga, Peia de Buenos Aires 20 October 0742 began sampling the linear grid. temp > 9°C, SW wind, strong; clouds 30%, TVC = 4000 fc. finished at 0820. Total: C. fuscicollis 15; C. bairdii, 1; Mimus parvulus, 5; Linsana hacaemotia 1; Pluvialis dominica 4; Hymenopus 3; Chaunotius falluklondus 1, Anas georgica 9, Anas flavirostris 2