California woodpeckers are well known to be sociable birds and to live more or less in communities or loose colonies, where food conditions are favorable. But a most remarkable story of apparently communal nesting is told by Frank A. Leach (1925). On February 2, 1922, he discovered these woodpeckers excavating a nest in a wooden trolley pole at Diablo, Calif. He estimated that they must have started work on this hole about the middle of January and thinks that it was some time near the latter part of April before it was finished. On March 1, he “saw two go in one after the other. Both appeared to be working on the inside. Two other birds on the pole showed interest in the work by remaining there and taking an occasional peep into the hole.” On April 3, there were “from four to six woodpeckers about the place all day. On one occasion saw three go into the hole. Heard digging while they were inside.” On April 17, he saw “three birds go into the cavity and soon after heard two of them working. Four other birds were on the pole, one looking into the hole.” The above extracts from his notes, made at frequent intervals and often for several days in succession, would seem to indicate that at least two, and possibly three, pairs of woodpeckers assisted in the excavation of that nest, but evidently their work was not very efficient, as the time involved was unusually long. The same cooperative behavior continued during incubation of the eggs and the feeding of the young, several different birds working in relays; and this continued during the rearing of three broods of young that season. He says that “in the case of the second brood, on eight different occasions I saw three different old birds feed the young ones in the nest, and at one time I witnessed a fourth one delivering food to them.” Referring to the third brood, he says: In the large oak tree standing so near the trolley pole that some of its outer branches nearly reached the pole, there were almost always from six to eight mature woodpeckers, all of which seemed to be interested in the welfare of the nestlings in the pole. I repeatedly saw three of them feed the youngsters, and on two occasions noted four different old birds perform this parental service. I was satisfied from the actions of the birds that a majority of the flock, if not all of them, participated in the care of the young woodpeckers. * * * For others than the parent birds to feed the young was a custom that was not confined to this group or flock at the trolley pole. At about the time the young were leaving that nest, I discovered another nest in a large oak tree situated about a quarter of a mile distant from the pole, where I found from one to five old birds, and possibly more, very busy feeding the nestlings.