SP Myrs 1974 Phalacrocorax olivaceus Arroyo Chico, Estancia Nodaland, 35 Kms. of Juncal by road, Pto de Madariaga, Proin de Buenos Aires, Argentina. new trick by cormorants again today (second hina) - Lani + I spotted them as we crossed the bridge. I drove upstream to the intersection of the fence further lower down + we waited till they came by - a 'flock' of 7 moving methodically upstream (5m every 5-10 sec or so) in close formation but but spread across our width of the stream (less than 4m wide now over most of this stretch). They are actually not evenly spread across but thus varies. Anyway they are for fishing - alternatively diving + swimming underwater, then swimming on top. As many as 5 have been under at once. Obviously fishing, as they will come up + swallow fish once above. Sometimes - after first dayter - they are so shallow as to leave a wake w/hack even while underwater. a cocoi heron appears to be following. We drove upstream to the curve entrance to the Arroyo from the fence in order to try + photo. about 500m in lake (or 5-3?) they came around the curve went by, continuing as before. Cocoi heron still with them. It thro ahead, almost like them pace, + then this ahead again.