ML638096730

媒体文件注释

Soon after we arrived (see previous checklist, S252930792), I saw bird hop up from shoreline to a low bare branch less than 1 m above the water. The bird spread its wings as if drying. I don't know if the bird had been taking a late-evening bath or feeding at the water's edge. The sun was down so the bird was not sunning. It remained in this position for several minutes. It suddenly hopped higher up into tree and I captured some of the commotion. I thought perhaps it had climbed up to roost there for the night. However, upon editing, I detected several hiss-like notes. You hear them beginning just before 19 seconds into the recording. The hiss notes become fainter, suggesting the bird was flying away from my position. This quality of the hiss is consistent with recording hiss notes for TUVU. I now think the bird must have climbed higher into the tree so that it had enough height to take flight. I have no explanation for why it called while flying away. No other birds were vocalizing at the time so I am as certain as I can be that the hiss notes are the TUVU. This is consistent with a second observation: later a bowfishing boat working the shoreline passed directly by the tree. I was surprised when I did not detect the vulture being disturbed.