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[[underline]]Tangara [[underline]], I.

March 26, 1961
Barro Colorado

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Watching the A pair of Plain-colored Tanagers again today, for a couple of hours after dawn

Today I noticed that there were 2 other birds more or less attached to the A pair.  Flew with the A's when the A's were feeding away from the nest. At such times, the A's did not seem to object to the presence of the other birds.  Right after dawn, when the A's first started to come to the nest, the other 2 birds frequently tried to follow them. The A's did seem to object to this, violently. The male A always drove the other 2 birds away, by a series of supplanting attacks. The male A uttered a few hard CN's and CN Trll's during these attacks, but performed no other displays.

The attacked birds usually retreated immediately, without display. But once one of the birds went into a slight TV Posture, drooped its wings, and Q'd (wings alone), as it retreated down an electric cable in front of the advancing male A. This TV & Q was silent, and was not accompanied by any trace of St. Must have been produced when escape was predominant. Possibly an appeasement pattern

After a while, the 2 other birds did not follow the A's to the nest very frequently. One still showed up occasionally, however, at least as late as 8:30 a.m

When the A birds first started to come to the nest just after dawn, they uttered CN Trll's, not free Notes, as they landed and when they moved about inside the nesting tree. They uttered CN Trll's in such circumstances when they were by themselves alone as well as when they were accompanied by one or both of the other 2 Plain-coloreds. By 7:30 a.m., however, the A birds had begun to utter Sreee notes inst