Unusual swifts
Usually there were few or no swifts in evidence from the canopy walkway. With patience, we would see small groups of swifts, mostly Short-tailed and Gray-rumped Swifts and Fork- tailed Palm-Swifts. One morning, however, we had the most spectacular display of swifts I have ever seen. It had rained hard all night and into the morning. Because we could not taperecord in the forest, we climbed to platform 6 where we stood in the driving rain under umbrellas (there was no thunder to concern us!). Suddenly, we were surrounded by swifts swooping low over the canopy and around emergents. Often we were looking down on them. Minna held the umbrella while I used my binocs in the pouring rain. At first most of the swifts were large. White-collared Swifts were easily identified -- complete white collars were clearly seen. Other swifts were nearly as long but slenderer. They had longish tails and some had dark rufous around the neck. At the time I was puzzled that some lacked rufous, but I had forgotten that female Chestnut-collared Swifts often lack the rufous. Those without rufous had exactly the same size and shape as those with rufous. As the rain eventually slackened to a steady drizzle, the big swifts disappeared, perhaps by rising higher in the sky, and scores of smaller swifts replaced them. There were many Short-tailed Swifts and Gray-rumped Swifts. A few were Band-rumped Swifts, very distinctive when seen from above. With them were a half dozen black-and-white swallows (see notes on unusual swallows). Fork-tailed Palm-Swifts were present also. Finally, as the rain slowly ended, the swallows disappeared. Only small swifts remained. These included an occasional (perhaps only one) stocky, nearly uniformly dark swift (slightly paler on throat and rump), presumably Chapman's Swift (or Amazonian Swift, if we follow Marin 1997). In addition, an occasional swift (again perhaps one individual seen several times) had much more extensive pale gray on the rump. Unlike the Gray-rumped Swifts, the gray extended to the end of the tail, presumably Ashy-tailed Swifts (or Sick's Swifts, according to Marin 1997). On other occasions on the canopy walkway, we noted an occasional Chapman's (Amazonian) Swift. On one occasion, an individual (or perhaps more) with Gray-rumped Swifts had noticeably paler (almost whitish rump) and more contrasty pattern below, possibly Pale- rumped Swift. These were the first occasions I had seen Ashy-tailed or Pale-rumped Swifts. In addition to those already mentioned, I have seen one other swift in lowland Loreto. In February 1997, I watched a flock of Chimney Swifts bathing early one morning in the Rio Tapiche (see http://www.unc.edu/ ~rhwiley/ birdsloreto/ tapichelist.html). These birds were dark with pale throats and rumps slightly paler than the back. Nothing resembling Chimney Swifts was seen at ACEER in July, when Chimney Swifts should of course be nesting in North America. The birds called Ashy-tailed (Sick's) Swifts above were noticeably paler on the rump and upper tail-coverts than are Chimney Swifts. The all-dark swifts mentioned above always looked stocky, a shade larger than other Chaetura present, and thus were presumably not Vaux's Swift, which in any case would be far out of its known range.
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