1177 the rim and rubbed himself down hard in it as if to shape it. He then settled as if incubating and I left to make this note. It is possible, of course, that Rhody is incubating--I have never looked into the nest. From all past behavior I have assumed him to be a male, but I have no proof of it whatsoever, merely circumstantial evidence , as it were. All of his actions have been those associated, usually, with males, but there is a possibility that roadrunners, like some other birds, reverse the usual attitude of the sexes toward each other. There is also a possibility that Rhody has a mate that I have never seen and that she has laid in the nest without my having seen her--a very doubtful contingency. Again, R may be a female with an extremely shy mate somewhere out in the hills and making occasional visits to him, then returning to lay an egg! Naturally the egg affair can be settled at any time by putting a ladder up to the nest, but this I do not want to do for several reasons. At the moment the most plausible supposition appears to be that Rhody, by sitting so long in the nest, is simply carrying out, impelled by instinct, his portion of the breeding pattern. That is to say, he is now doing his share of the incubation which normally should be in progress now, but which is not actually taking place because there are no eggs by reason of his being mateless. During the rest of the day he was not seen to visit any other nest, but he sat in nest 1-36 twice more. He is paying much less attention to the magpies now. May 3rd. Rhody did not sing at all yesterday, nor has he up to now, 7:30 A.M. At 7:15 Rhody, or at least a roadrunner, was sitting motionlessly in nest 1-36. I suppose it was Rhody, but did not talk to him to find out, thinking that it might be a mate. At 11 I heard Julio scolding Rhody by the observatory where I was adjusting the clock of the equatorial . He seemed excited. I went down quickly. Rhody was trying to get at Brownie's nest and Brownie was defending it, making harsh sounds like a shrike. B attacked R fiercely, dashing at him from the nest, and R fled, only to return to the nest when B reentered it. This was repeated several times, B chasing R down the road. Julio said that, before I arrived, B had chased R about in circles, R using both wings and feet to escape. Rhody was perfectly bare-faced about the matter, disregarding our presence a couple of yards away, where we had stationed our- selves in order to observe and intercede on the part of Brownie if necessary. Brownie's defense triumphed, although we aided to some extent by getting R interested in the mouse-prospect. R took the mouse and carried it to 1-36. He was still there at 1 P.M. It was this sort of thing that caused me to put Rhody in jail two years ago. I doubt if he would have taken B's eggs if successful in driving him away, but I have no illusions as to w what would have happened if he found youngsters in it. During the rest of the day Rhody stayed about the place, being seen several times in nest 1-36, but not in any of the others. Notwithstanding the many evidences of tameness cited in these notes, he continues to be suspicious of strangers and in actual