Walking along the water if you see a black-necked stilt, it's hard not to notice its slender pink legs. They are a locally abundant shorebird of American wetlands and coastlines. The Black-necked Stilt can swim and dive but prefers to wade in shallow water. It feeds on insects, small crustaceans, tiny fish as well as some seeds of aquatic plants, brine shrimps and brine flies. Black-necked Stilts nest on open ground in loose colonies. They tend to build on surfaces above water. They are classified as semicolonial since the nests are rarely found alone and colonies usually number dozens, rarely hundreds of pairs. Both sexes participate in incubation and chick-rearing. These shorebirds are strongly territorial. They have shown different types of display lure potential predators away from the birds' nests and eggs. On July 8, 2020 at Peck Road Park, I saw two Black-necked Stilt flying in a circle and calling loudly for quite awhile. I had no clue what was going on at the time. After I came home and saw the pictures on a larger screen, I saw two little chicks in the water. Then I realized that they were performing the anti-predator display.
走在水邊，如果看到黑頸長腳鷸，很難不注意到它細長的粉紅色腿。它們是美國濕地和海岸線當地豐富的濱鳥。黑頸長腳鷸可以游泳和潛水，但更喜歡在淺水中涉水。它以昆蟲、小型甲殼類動物、小魚以及一些水生植物的種子、豐年蝦和豐年蟲為食。黑頸長腳鷸在空地上成羣營巢。 它們傾向於在水面以上的表面上建巢。它們被歸類為半群居，因為很少發現單巢穴，群落通常有數十對，很少有數百對。兩性都會參與孵化和育雛的責任。這些濱鳥有很強的領地意識。它們用不同類型的炫耀行為，來引誘可能的捕食者遠離鳥巢和蛋。2020年7月8日在佩克路公園，我看到兩隻黑頸長腳鷸盤旋飛翔，大聲叫了好一會兒。我當時不知道發生了什麼事。當我回到家在大屏幕上看這些照片時，我看到水中有兩隻雛鳥。然後我才明白原來那是它們對侵犯者的抗議警告動作。
Notes 筆記
- The black-necked stilt, with long rose-pink legs, a long thin black bill, and elegant black-and-white plumage, is a shorebird of American wetlands and coastlines. They have the second-longest legs in proportion to their bodies of any bird—only a flamingo's are longer. They are found in wetlands from North America and the Caribbean south to central Argentina.
- The Black-necked Stilt can swim and dive if necessary, but prefers to wade in shallow water as it feeds, probing with its long, thin bill for insects and crustaceans on or near the surface of water. It finds most of its food visually, picking insects, small crustaceans, and tiny fish from the surface of the water or mud. Stilts also eat some seeds of aquatic plants, and on some lakes, may feed heavily on brine shrimps and brine flies.
- Black-necked Stilts nest on open ground in loose colonies, sometimes alongside other shorebirds such as the American Avocet. The nest site is usually located on bare open ground or in short vegetation, surrounded by water; the nest itself is built by both sexes, and may be a simple scrape in the soil or a mound of vegetation built up above water level and lined with pebbles, shells, and debris. The black-necked stilt is actually classified as semicolonial since the nests are rarely found alone and colonies usually number dozens, rarely hundreds of pairs.
- Black-necked Stilts are especially animated during the breeding season, when females select males for mating. Just before mating, the female stretches out the neck and preens; the male faces her and does the same. Both dip the bill in the water and preen the breast, and this action becomes increasingly frenzied, with much splashing just prior to copulation. Afterward, the pair crosses their bills and runs together for a few steps.
- Both sexes participate in incubation and chick-rearing, though males appear to accompany older chicks more often than females. On very hot days, stilts may soak their belly feathers to carry water to the nests, sometimes making more than a hundred trips a day to keep their eggs cool. The downy young leave the nest only an hour or two after hatching. And although both parents tend the chicks, they are capable of feeding themselves.
- These shorebirds are strongly territorial and attempt to deter potential predators with “broken wing” distraction displays. Another distraction display they deploy is “false incubation,” in which an adult crouches on the ground—as if incubating eggs—then gets up, moves to another spot, and crouches again. Both types of display lure potential predators away from the birds' nests and eggs. Sometimes, stilts will strike humans from behind with their legs if the humans approach the nest too closely. Territoriality extends to driving out young birds as well: adults sometimes attack stilt chicks that are not their own and even avocet chicks. Small chicks can dive and swim underwater to avoid hostile adults and predators.
- A unique display the stilt uses is the “popcorn display”: all the adult stilts in a colony alternately hop up and down while wildly flapping their wings and calling loudly and incessantly at offending intruders.
- 黑頸長腳鷸，長著玫瑰粉色的腿，細長的黑色喙，優雅的黑白羽毛，是美國濕地和海岸線的濱鳥。就其身體比例而言，它們的腿是所有鳥類中第二長的，只有紅鸛的腿比它更長。它們分佈在從北美和加勒比海南部到阿根廷中部的濕地中。
- 黑頸長腳鷸喜歡在淺水中涉水進食，用細長的喙探測水面或水面附近的昆蟲和甲殼類動物，但必要時它可以游泳和潛水。它的大部分食物都是靠視覺找到的，它從水面或泥土中捕食昆蟲、小型甲殼類動物和小魚。長腳鷸也吃一些水生植物的種子，在一些湖泊上它們還可能大量捕食豐年蝦和豐年蠅。
- 黑頸長腳鷸在空地上成羣營巢，有時與其他濱鳥如美國反嘴鷸一起生活。巢穴通常位於裸露的空地或矮小的植被中，周圍有水；巢本身是由䧳雄兩性建造的，可能是在土壤中簡單的刮擦，也可能是在水面以上築起的植被堆，裡面鋪滿了鵝卵石、貝殼和碎片。黑頸長腳鷸實際上被歸類為半群居，因為很少發現單巢穴，群落通常有數十對，很少有數百對。
- 黑頸長腳鷸在繁殖季節尤其活躍，此時母黑頸長腳鷸選擇公黑頸長腳鷸進行交配。交配前母黑頸長腳鷸會伸出脖子進行梳理，公黑頸長腳鷸面向她並做同樣的事情。兩者都會將喙浸入水中並梳理胸部，這種動作會變得越來越瘋狂，在交配前會濺起很多水花。隨後兩人交叉著嘴，一起跑幾步。
- 兩性都參與孵化和養育雛鳥的責任，雖然公黑頸長腳鷸似乎比母黑頸長腳鷸更多地陪伴年長的雛鳥。在非常炎熱的日子裡，長腳鷸可能會浸泡腹部的羽毛，將水帶入巢穴，有時一天要跑一百多次，以保持蛋的涼爽。毛茸茸的雛鳥在孵化後僅一兩個小時就能離開巢穴。雖然父母雙方都會照顧雛鳥，但雛鳥它們能夠自己進食。
- 這些濱鳥具有強烈的領地意識，並試圖藉“斷翼”分散注意力的行為來阻止可能的捕食者。它們另一種分散注意力的行為是“假孵化”，其中一個成鷸蹲在地上就像孵蛋一樣，然後站起來，移動到另一個地方，然後再次蹲下。這兩種類型的表現都會引誘可能的捕食者遠離鳥巢和鳥蛋。有時如果人太靠近巢穴，長腳鷸會用腿從後面攻擊人類。領地意識還延伸到驅趕幼鳥：成鳥有時會攻擊不屬於自己的雛鳥，甚至是反嘴鷸雛鳥。小雛鳥可以在水下潛水和游泳，以避免敵對的成鳥和捕食者。
- 長腳鷸使用的另一種獨特的炫耀行為方式是“爆米花展示”：群落中的所有成年長腳鷸交替地上下跳躍，同時瘋狂地拍動翅膀，大聲不間斷地向冒犯的入侵者呼喊。
Birds Posts 鳥的帖子
References 參考資料
- Wikipedia: Black-necked stilt
- American Bird Conservancy: Black-necked Stilt
- All about birds: Black-necked Stilt