成年疣鼻天鵝帶領幼鳥在烏梁素海覓食（無人機照片，9月14日攝）。烏梁素海，意為“紅柳湖”，位于黃河“幾字彎”頂部，是黃河流域最大的湖泊濕地。近年來，隨著烏梁素海生態治理力度不斷加大，生態成果也不斷顯現。各類候鳥在這里安了家，本來前往西伯利亞的疣鼻天鵝也在烏梁素海產卵孵化生活，烏梁素海成為我國最大的疣鼻天鵝繁殖基地。近日，在烏梁素海湖面上，成年疣鼻天鵝帶領幼鳥練習飛翔，準備為過冬前的長途遷徙做準備。[新華社記者 邢廣利 攝]

This aerial photo taken on Sept. 14, 2023 shows mute swans and fledglings foraging on the Ulan Suhai Lake in Bayannur, north China's Inner Mongolia Autonomous Region. Located at the apex of the meandering bends of the Yellow River, Ulan Suhai Lake, also known as Wuliangsu Lake, is the biggest lake wetland of the Yellow River basin. With continuous efforts on integrated protection and systematic management, the ecological environment of the Ulan Suhai Lake has been greatly improved in recent years. The Ulan Suhai Lake is now home to various kinds of migratory birds. It also serves as the largest breeding base of mute swans in China. Recently, mute swans on the Ulan Suhai Lake led fledglings to practice flying, preparing them for the long-distance migration before winter. (Xinhua/Xing Guangli)