ML92891721
- 年齡
- 未確定
- 性別
- 未確定
觀察細節
First individual seen ca 1123 or 1124, flying upstream relatively low in reach 3, ca 3-4x shrub height, alternating glides with wings held in strong dihedral with heavy-seeming flaps in series of between ca 5 and 15. At 1125 it started circling above the diversion area, still along the stream. At 1126 another joined it, apparently from somewhere off to the W, and then I glimpsed a third individual over my right shoulder, flying upstream at ca 3x shrub height, also alternating flaps and glides. I made notes via my sound recorder in the field from ca 1125 until 1130. Those notes follow; times with colons represent mins:secs after beginning recording. At 1:30 I noted that the vultures did not seem to be getting a whole lot of lift, though one was getting some over the diversion; the 2 others were farther upstream. At 1:40, 1 landed in an apparently dead shrub N of the diversion and the 2 others circled in the vicinity, 1 relatively low; it landed at 1:57. At 2:05, the other flew overhead them at ca 5x shrub height; it was still circling over them at 2:15. At 2:30 a fourth individual ("#4") approached from downstream, alternating flaps and glides. At 3:00 there were still 2 in the air and 2 perched in the shrub. At 3:10, #4 was now gliding, rarely with small flaps; the other bird in the air was alternating flap and glide. At 3:30, 1 of the 2 in the shrub resettled a little bit. At 3:45 #4 was now circling low over them with a bit of flapping. By 3:55 I lost sight of the other bird in flight. At 4:10 #4 was still circling over the two that were perched. At 4:17 #4 landed with them, holding its wings outstretched for ca 13 seconds more before folding them. At this point I stopped the focused TUVU observation. Weather at this time: wind more or less calm, but probably light air from E or SE; still very hazy in the valley; fully sunny and had been all survey so far; cloud cover now broken, mostly high gauzy indefinite stratus, with a bit of cumulus development to the SW over the Boulder Mtns. At ca 1132, I noted 3 TUVU circling low over the same area with a lot of flapping and none perched. Ca 20 seconds later, all three were still circling together, not flapping as much. They continued to circle together, apparently getting a bit of lift - by 1 min 30 secs after noting them circling they had stopped flapping and were gaining some altitude. A few minutes before 1455, I saw a single TUVU approach from upstream towards the raised hill, circle a bit, then continue to the NE. Mostly soaring. Weather conditions: light to gentle E breeze, cool, 90% stratus clouds, weak and variable sun. At 1527, I saw 1 TUVU and 1 adult light-morph RTHA both soaring over the grassland N of reach 3 with gentle E breeze and weak sun. Another Buteo (RTHA?) seen higher in the same vicinity, but it glided distant N before I could ID it. At 1531, I saw a second TUVU alternately glide and flap over this area, lower, heading W.
技術資訊
- 型號
- COOLPIX P900
- ISO
- 100
- 焦距
- 714 mm
- 閃光
- Flash did not fire, auto
- 光圈值
- f/6.5
- 快門
- 1/1250 sec
- 次方
- 3070 pixels x 2304 pixels
- 原始檔案大小
- 578.81 KB