Red-eyed Cowbird May 30 Zoo in Chapultepee Park, Mexico City. In a large cage for birds - containing several English sparrows, 2 Orioles, a Pipilo fusces, one Turdus gragi and 1 or 4 ? cowbirds. Hard to tell whether all there were actually con- fined; 3 ? Cowbirds were feeding on floor of cage as was o?, the latter reported from ?? which more often tended to feed in same general area but often wandering apart or flying up to perches independently. o? seemed to be doing less feeding than ?? and always had his neck feathers puffed up, also sometimes the belly feathers. We noted him several times before we observed the following mating behavior. The o? began quivering his wings rapidly - actually flapping the wings out from his body a short distance. At same time the feathers of the bird neck & underparts were puffed out more than before. He walked around a bit, still flapping the wings rapidly, obviously trying to attract the attention of a ? which was feeding about 1 foot away from him. After a moment the ? stopped feeding and stood quickly watching. The o? approached, now flapping more rapidly and when a few inches away from the ? he rose from the ground and hovered closely above the ? -