鷉形目 Podicipediformes

鷉形目 Podicipediformes，來自拉丁文的 pōdex (肛門、臀部)，pēs (腳)，和 -fōrmis (形狀)，意思是「後端腳」，說明是這些動物的腳是比大多數鳥類的腳更靠後。

Podicipediformes, from Latin pōdex (“anus, butt”), Latin pēs (“feet”) and Latin -fōrmis (“-shaped”), means “rear-ended feet”, in reference to the fact that these animals feet are set further back than in most birds.

種的俗名 Common names of members

鸊鷉。

Grebes.

分佈 Distribution

世界各地，除了北極、南極及一些大洋島嶼。

Almost worldwide expect from the Arctic, Antarctic, some oceanic islands.

體型 Size

長度範圍是23.5厘米到71厘米之間，體重範圍是20克到1.7公斤，因此牠們體型是屬於小到中大。

Their sizes range from 20 g and 23.5 cm to 1.7 kg and 71 cm, making them small to medium-large.

形態 Morphology

牠們的腳很大，前三個腳趾上有細小的蹼和有寬闊的葉瓣，後腳趾亦都有一個小葉。爪子偏平，類似指甲。股骨和跗蹠骨 (腳骨) 位於身體後端的位置，且長度有差異。根據物種的不同，翅膀可以很長，亦可以非常小巧且呈圓形。濃密的捲曲和極高密度是羽毛的特徵。較小物種的羽毛比較長但更薄，而較大物種的羽毛較短但更密。

Their feet are huge, with tiny webs joining the first three toes and wide lobes on the toes. There is a tiny lobe on the hind toe as well. The claws are flat and resemble nails. The femur and tarsometatarsus, the leg bones, are situated far back on the body and have comparable lengths. Depending on the species, wings can be anywhere from quite long to exceedingly small and rounded. Strong curls and extreme density characterize the feathers. Feathers of smaller species are longer but less thick than those in larger species, which have shorter but denser feathers.

生態及棲息地 Ecology & Habitat

許多種累的鸊鷉棲息在湖泊和沼澤等水域。然而，隨著冬季的鄰近，住在北半球的鳥們將遷移到沿海海洋棲息地。

Many species of grebes inhabit watery settings such as lakes and marshes. However, the North Hemisphere ones will relocate to coastal maritime habitats as winter approaches.

食性 Diet

較小的物種是相對矮和壯，喜歡捕食小型水生無脊椎動物。較大的物種則有矛狀的喙，可以讓牠們在中段深層的水捕食魚類。

While smaller species tend to be short and robust and like to catch small aquatic invertebrates, larger species have spear-like bills that allow them to grab fish in the mid-depths.

繁殖 Reproduction

他們是季節性的一夫一妻制。最出名是牠們的求愛儀式，大多數物種會表演二重唱，其中許多都有自己的同步儀式。完成這些求愛儀式後，這對伴侶登上被植物覆蓋的平台並開始交配。孵化可能需要長達一個月的時間，雌性可以產下2–7個卵。巢中的雛鳥會在不同時間孵化。當整個巢孵化出來，雛鳥們會開始爬到父母的背上。與其他水禽不同的是父母雙方會參與照顧幼鳥，因此時間是比較長但幼鳥的生存機會更高。當一位父母留在水面上監督雛鳥時，另一位則潛入水中尋找食物。

They are seasonally monogamous. And their intricate courtship displays are what make them most famous. A duet is performed by most species, and many of them have synchronized rituals of their own. Following the completion of these courtship rites, the couple mount on vegetation-covered platforms and request copulation. Incubation can take up to a month, and females can deposit two to seven eggs. The nest's chicks hatch at different times. The chicks start to climb on one of their parents' backs as soon as the entire nest hatches. Unlike other waterfowl, the time spent caring for their young is longer when both parents are involved. The chicks have a higher chance of surviving as a result. While the other parent stays above the surface to supervise the young, one parent dives for food.