ML620277187
投稿者
日付
場所
- 年齢と性別
- 未成鳥 性別不明 - 2
視聴覚メディア・ノート
Appearance consistent with first-summer Bonaparte's.
観察結果の詳細
From the main PL, I observed 5x average-sized gulls (probably California) swimming near the west PL, but there were two smaller birds swimming behind the gulls that piqued my interest (see first slide). They were much too far away to identify with bins and camera but I figured they had to be something interesting -- terns or phalaropes or a rare gull species. I drove to the west PL to get a better look. By the time I got there, the average-sized gulls had moved so far out on the lake that they were now closer to the east shore, and I couldn't find the small birds. I drove *back* to the main PL and was chagrined to find that the two small birds were near the west PL again -- right at the mouth of the feeder canal! We were playing hide-and-seek!! I drove to the west PL for the second time and managed to get diagnostic pictures of three small gulls that were consistent with non-breeding Bonaparte's (see second slide). They had thin dark bills, dark eyes, and dark spots behind the eyes. I was initially confused because at this late date, all adult Bonaparte's should have the hooded breeding appearance. I consulted with my friend Sam Fellows. He informed me that first-summer Bonaparte's generally do not develop the black hood. I copied the following from Wikipedia: "First year Bonaparte's gulls have the same plumage in winter and summer, but the summer plumage is paler due to wear. Fewer than 5 percent of Bonaparte's gulls acquire a dark hood in their first summer, and on those that do, the hood is duller than on breeding adults."
テクニカル・インフォメーション
- 大きさ
- 1200 pixels x 900 pixels
- オリジナルのファイルサイズ
- 221.67 KB