ML380844851
投稿者
日付
場所
- 年齢
- 指定なし
- 性別
- 指定なし
観察結果の詳細
Lifer! Seen just west of the farmhouse and barn where Stacy Robinson had reported the bird earlier today! The picked up from the field and then soared on the strong north winds south toward the treeline. It landed in a tree and then took off and continued soaring (wings in dihedral) and drifting southward slowly until it went out of sight. More detailed description of ID and photos of the bird to come. *Edit 10/18 John Peckham first spotted this bird take of from the ground and fly low along the border of a grass and cut corn field (SWHAs apparently are known for spending lots of time on the ground and even walking around hunting grasshoppers and other prey!). I was able to get on this very dark raptor as it was flying away from us and quickly identify it as a likely suspect for the continuing dark morph juvenile SWHA reported earlier in the day. At a distance of about 50 yards I noted a uniformly dark mantle and wings with light edging seen along the edges of the feathers on the bird's mantle. This was the only time that the bird was close enough and in good enough lighting to clearly see these markings. The bird then perched in a snag along the far tree line to the south for about 40 seconds, just enough time for me take a quick look at the bird through my scope and to grab my camera, before taking off and soaring above the tree line, riding the strong northwest winds. It was at this time that I noted a light silver color to the underside of the tail feathers, the obvious dihedral that the bird held it's wings in while soaring and some light colorations to the primaries and secondaries feathers, the extent of this coloration was only determined by examining photographs taken during this time of observation. The bird's wings appeared slender and pointed and the flight was surprisingly buoyant (not as stiff-winged as your typical BAEA, PEFA, or RTHA) for such a big raptor. While the bird was perched, I was able to note a dark line extending behind the eye and some lighter colorations on the head and upper breast. The bird continued to drift slowly to the south under observation, working the next farthest tree line from east to west and then back again before finally disappearing from sight. After the observation, a variety of field guides were consulted and photos were reviewed. Photos of the bird in flight showed that the upper wing coverts and mantle were a deep brown, while the primaries and secondaries appeared a few shades darker. Juvenile dark morph (JDM) RLHA would show a pale upperwing patch, not seen on this individual. Yellow feet could be seen tucked up against light buffy colored under tail coverts that contrasted nicely with the dark splotched belly and breast. The under tail showed faint thin gray lines on otherwise silvery backdrop that got progressively darker toward the tip of the tail feathers. The upper sides of the tail feathers were consistently dark gray with some thin barring, not showing any light coloration (helping to rule out Harlan's subsp. RTHA). A black comma-shaped mark could be seen clearly at the base of the primaries with a small light spot separating this marking from the more interior dark underwing coverts. The base of the primary feathers were lighter than the tips from the underwing as well, adding to the contrast of this "comma". Neither the primaries, nor the secondaries, were especially silvery, as would be expected in a DM RLHA or Harlan's subsp. RTHA and the small comma-shaped marks were not nearly extensive enough to be the dark wrist patches of a JDM RLHA. The tail also lacked a clear terminal band, as would be expected on an adult DM RLHA. Documentation photos attached, see other checklists from same location and date for better photos of this bird.
テクニカル・インフォメーション
- モデル
- NIKON D3500
- ISO
- 280
- 焦点距離
- 500 mm
- フラッシュ
- Flash did not fire
- Fストップ
- f/5.6
- シャッタースピード
- 1/400 sec
- 大きさ
- 457 pixels x 305 pixels
- オリジナルのファイルサイズ
- 60.83 KB