1980 R.L.Munne 29 Melanerpes formicivorus Plague (12 July) juveniles here. Yesterday afternoon I noted from the cabin that nobody was visiting the nest anymore. Four of the juvs probably fledged then on 16-11 July (birds were still feeding at nest at 2000 10 July). However, this does not bode well for the runt, who seemed too poorly developed to fledge. However, on my 9 July Nestwatch, he was looking out of the hole and being fed. Thus far this Am I've seen only 1 juv (couldn't see birds). Also checked area of Cooper's Hawk nest, negative for remains of AW. 0925 J606 BPhk-wh/r seen at least 1000 "A major disaster. I go up to the hole and find 4 dead juveniles, only J605, 607, 608, 609. Very bizarre. Covered with ants, beginning to rot. Why did they die? Certainly they were being fed with enthusiasm on 9 July, and, as I watched from the cabin, on 10 July. No feedings seen yesterday. Weights of the dead birds seemed pretty good, despite their decomposed state, Gizzard of one was empty (except for rocks), but that doesn't imply starvation really. Could the ants (I collected many) have killed them? Could runt J609 died first (he seemed to have died before the others) and attracted ants or other diseases? Certainly he couldn't have died until 10 July, because he was healthy, looking out and being fed on 9 July. Disease? We searched the nestlings and found nothing suspicious inside. It real mystery. However, they were not predated.