North American Birds

VOLUME 70 NO1 2017

A Quarterly Journal of Ornithological Record Published by the American Birding Association. The mission of the journal is to provide a complete overview of the changing panorama of our continent’s birdlife.

Issue link: http://nab.aba.org/i/936087

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N O R T H A M E R I C A N B I R D S 14 F I R S T U. S . R E C O R D O F A M E T H Y S T - T H R O AT E D H U M M I N G B I R D and madrone. Emory and gray oaks are mixed within the woodland in places and there are a few enclaves of Chisos red oaks on the upper slopes. Other minor components of the vegeta - tion include choke cherry, mountain mahogany, Arizona ash, and Mexican walnut. The ground cover is primarily composed of grasses and lacks a shrub component except where young silver-leaf oaks form shinnerys or thickets. Description Video footage of the first visit to the cam feeder, courtesy of the Macaulay Library, can be viewed at tinyurl.com/Cornell-TX-ATHU. Analysis of the video shows that the bird is similar in size to a Blue-throated or Rivoli's hummingbird. It is almost certainly a juvenile male due to three features clearly noted in the bird's plumage. First, the gorget pattern of pinkish-red irides - cent feathers is incomplete, indicating that it is indeed a male and almost certainly a juvenile. Second, this bird shows a great deal of buff–tan coloration on the lores, upper chin and eye - brow. These are juvenile characteristics in sev- eral species of hummingbirds as illustrated in various guides. Finally, the bird is in completely fresh plumage with no molt of any kind noted. Adult birds are normally in worn plumage several photographs, though none were in op - timum lighting conditions. Just before sunrise the next morning, the Amethyst-throated Hummingbird was back on the cam feeder and within the next 20–30 min - utes Bryan heard it vocalizing from the trees off the front deck. However, by the time four additional observers arrived (Cecilia Riley and Michael Gray at approximately 9:00 am; Marc Eastman and Maryann Eastman at approxi - mately 9:30 am) no more vocalizations were noted, and the bird never appeared again on any of the feeders. At approximately 12:30 pm we concluded that the bird had likely moved on. Bryan was able to watch the feeders peri - odically for the rest of the day, and the follow- ing couple of days with no additional sightings. Habitat The elevation at the location of the observation is 6,300 feet. Ridges above the property to the east, south, and west are above 7,000 feet, and the habitat in the canyon can be characterized as pine–oak woodland containing an overstory of ponderosa pine (90% killed by pine bark beetles during the drought of 2011 and 2012) with an understory of dense silver-leaf oak and scattered pinyon pine, alligator juniper, Once again, it chose the same perch and port on the live cam feeder. Bryan was able to take 17 pictures with his camera during this visit, which lasted approximately 30 seconds. From there the bird moved to the backside of a differ - ent feeder where Bryan took two photographs of the underside of the tail. The bird's next appearance was at 4:05 pm that day. The hummingbird settled in on the same perch on the cam feeder allowing Bryan to take 24 additional pictures. It appeared again at 4:20 pm but chose a different feeder not al - lowing any photographs, then returned once more to the cam feeder at 4:50 pm. With this visit Bryan took 6 additional pictures, although the photographs taken were not as useful due to building clouds obscuring the sun. Then, at 5:05 pm the hummingbird again visited the feeder hanging to the left of the cam feeder. Within the next thirty minutes a third ob - server, Carolyn Ohl-Johnson, arrived but by now the sun had dipped below the ridge south - west of the cabin. The next visit, at 6:05 pm, was also to the feeder to the left of the cam and at 6:50 pm to yet a different feeder. It made its last visit of the evening at 7:21 pm just be - fore dusk to a feeder on the opposite end of the deck. Ohl-Johnson was also able to obtain Fig. 3. In addition to details of the facial pattern and the color of gorget, the identification of this hummingbird hinged upon study of the tail pattern. In Amethyst-throated Hummingbirds, the tail is dark with broad, dusky grayish corners to the outer tail feathers. In the Blue-throated Hummingbird, these tail corners are bright white. This photo shows the distinctive grayish edging on the folded tail. Photo by © Kelly B. Bryan.

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