(467) Rapid changes of shift. 6:45 P.M. At 5:29½ the birds changed shifts. I was curious to see where Brownie would spend the night in the event of Greenie's taking the night shift. In the next 14 minutes they changed shifts six times and I was hard put to it keep track of the two birds, in fact was unable to tell which was which, until on the 6th. change Brownie came to me as Greenie went to the nest. The 7th change occurred at 5:40, when Brownie went on duty and Greenie went up into her (now) tree, from which Spotted Towhees were driven out. It was now dark inside the trees and I had no flash light, but I could see B's tail against the sky, projecting from the nest. This seemed to indicate that B would occupy the nest for the night, and G the usual tree. I heard rustlings in the lower branches of B's tree (these branches hang clear to the ground on the south side) and went in to see what other birds were roosting there, when there was a sudden movement, a loud sc rip, followed by a queelick almost in my face. B was still in the nest, so this seemed to indicate that G either intended to take B's place in the nest or roost in the same tree. G not located. I got a flash-light and could not find Greenie in either tree, nor was she in the house. Alarm calls. Incidentally it appears that sc rip and queelick may be used as alarm calls at times. G(?) still not located. 7:50. P.M. The bird in the nest does not appear to have moved since last observed. The other could not be found in either tree or in the house. It may be in the nest also, but this could not be de- termined from the ground. Copulation. I omitted to record that the birds copulated while the sixth change was in progress.