燕在柴灣 Swallows in Chai Wan
(Scroll down for English version)
“家燕”是為人熟悉的野生動物之一。每年春天，家燕都會飛返香港繁殖。自人類社會出現，自然地貌受不同程度地改變。但經過漫長的演化，家燕成功活用人類的建築，與此共存。
我們閱讀詩人白居易的《燕詩》，得知他對燕子的觀察入微，但對其行為未必理解。現在就為白居易來個“超時空”生態導賞。
<梁上有雙燕...銜泥兩椽間> 家燕通常會在屋簷下築巢，特別是在香港的工廠大廈、唐樓和村屋。柴灣的工業區就是理想的落腳點。雌雄家燕以唾液混合濕泥、乾草和樹枝，在墻壁上一口一口地搭成杯狀的巢。於是有“銜泥”之說。
<黃口無飽期> “黃口”指的是幼鳥時期鮮黃色的口部，是展示給父母看的餵食標記，長大後消失。不只家燕，幾乎所有幼鳥都有類似的結構。每次父母回巢，燕BB便急不及待的把口張開，展示黃色的大嘴，爭取被餵食的機會，好似有種唔會食飽，即“無飽期”的感覺。（留意短片結尾的慢鏡）
<一旦羽翼成，引上庭樹枝> 一旦幼鳥的羽毛生長好，會在父母的引領下出巢，學習飛行和捕獵技巧。假如出巢的幼鳥仍然張口要食，有機會遭到父母的狠狠冷待。
<舉翅不回顧，隨風四散飛> 長大成鳥，就會四處覓食。燕巢的作用只是為了繁殖，平時不需要。若鳥巢的結構和衛生情況尚可（沒有寄生蟲），下一年的家燕有機會重用。
自古以來，家燕都是有福的象徵，仲幫人類食唔少飛蚊呢？這是經千年進化磨合的緣份，大家要好好珍惜，要愛護牠們的幼鳥和巢，還有附近的自然環境。
Reference
The Barn Swallow is one of the most familiar birds for Hong Kong people. In spring, Barn Swallows return to Hong Kong to breed. Although the natural habitat has been changed and destroyed for thousands of years, barn swallows can evolve and adapt to living in the urban city.
A renowned Chinese poet BAI Juyi in Tang dynasty observed the swallows and wrote a poem "Yan Shi" (The story of swallows).
We all know that a couple of swallows would build the nest under eaves. The nest is made from a mixture of saliva and mud in the shape of a small bowl.
Mr. Bai said, "The baby birds never feel full white presenting yellow mouth." Actually, the flexible yellow skin at the corner of mouths allows their beaks to open widely when parents feed them.
When the birds become fully-fledged, they are ready to fly. The parents start to teach them how to feed and survive. The bird nest is used as a nursery for a few months. So the nest can be shared or reused by several swallow families year after year.
In ancient China, people believe that the swallow is the symbol of blessing. Nowadays, we know that swallows can eat thousands of mosquitoes and help pest control. How can we protect the incredible barn swallows? Become a citizen scientist and keep tracking nest to help protect them in your area.