Water Caltrop Pond 菱角池
Stop 2 of the Wetland walk · 濕地路線第2站
The first eco-pond, dug in 2024 higher up the farmland: it stores water for the dry season and the paddies.
Water caltrop was planted, as in Taiwan, for the Pheasant-tailed Jacana. It once bred in Hong Kong and has been seen at Shui Hau.
Fox nut is being tried here too.
Floating leaves are a jacana's home. On its very long toes the jacana walks across them, hunting insects and snails, and it builds its nest on the leaves. The female lays about four eggs and leaves; the male sits on them and raises the chicks.
Why is there no water caltrop now? Invasive apple snails ate it. They lay bright pink eggs above the water, on stems and leaves, and the team picks off snails and eggs by hand.
Part of the pond is kept deep. Ducks such as Eurasian Teal rest on open, deep water, away from dogs and other predators, and Little Grebes dive there for fish; the shallow edges suit herons and waders.
Some animals here were released by people from outside: guppies and other aquarium fish, and the apple snails. They eat or crowd out native wildlife. Please never release pets or aquarium animals into the wild.
2024 年在農地上游設立的第一個生態池，旱季儲水並灌溉米田。
參考台灣經驗種植菱角，希望吸引水雉；水雉曾在香港繁殖，水口亦有記錄。
團隊亦在此試種茨實。
浮葉就是水雉的家：水雉靠特長的腳趾在浮葉上行走，捕食昆蟲及螺類，並在浮葉上築巢。雌鳥產下約四枚蛋後便離開，由雄鳥孵蛋及照顧幼鳥。
為何現在看不見菱角？因為入侵的福壽螺把菱角吃光了。福壽螺會在水面以上的莖葉產下鮮粉紅色的卵，團隊要以人手撿走螺及卵。
水池部分位置刻意保持較深：綠翅鴨等野鴨喜歡在開闊深水處休息，遠離狗隻等天敵；小鸊鷉亦要潛入深水捕魚。淺水的池邊則適合鷺鳥及涉禽。
這裏亦有外來人士放生的動物，例如孔雀魚等觀賞魚及福壽螺，牠們會捕食或排擠本地野生生物。請勿放生寵物或觀賞動物。