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40

Aramides cajauea, July 30, 1960, II     

hostile??? I think so.

I noticed that most of the time when the birds were not obviously alarmed, just feeding and moving around their cage, they did not perform ck Movements. When they are not performing ck's their tails are kept more or less horizontal, and their wings are usually held up, resting on the rump. As soon as they begin ck, however, the wings are apparently always drooped a little.

I am now fairly certain that the ck Movements are an indication of alarm,,or, at least, mild hostility in which escape is slightly predominant.

While the birds were feeding and moving about their cage, they uttered numerous series of brief soft notes.  All or most of their series were quite rapid. They appeared to be either rapid RP2s and/or Trills. The occurrence of such notes, so frequently in such a context, is perhaps rather surprising, as we could not provoke Trills and provoked very few RP2's during tests immediately beforehand (see below). This would suggest that the motivation of such Trills or RP notes at this time is somewhat different from the motivation of the Trills and RP notes uttered by the birds before I went to Washington. (If the Trills and/or RP notes at the present time are produced by eventually the same motivation as the similar-sounding notes a few weeks ago, then it is possible that they are inhibited by strong escape motivation, and that the birds are too frightened during tests now.)

I am certain, in any case, that all or most of the Trill-like or RP-like notes uttered by the birds today were not uttered when they were running. When they were either standing still and/or walking about quite slowly.

I think that these notes were uttered both by birds performing ck Movements and by birds not performing such movements; but