Yaks pass through a culvert beneath the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region, June 18, 2026. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)

Yaks pass through a culvert beneath the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region, June 18, 2026. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)

An aerial drone photo taken on June 18, 2026 shows a flock of sheep preparing to pass through a culvert beneath the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)

Yaks graze near the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region, June 18, 2026. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Li Mengxin)

An aerial drone photo taken on June 18, 2026 shows yaks grazing near the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Yang Zhisen)

An aerial drone photo taken on June 18, 2026 shows a herd of yaks crossing a creek after passing through a culvert of the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)

An aerial drone photo taken on June 18, 2026 shows a herd of yaks crossing a creek after passing through a culvert of the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)

An aerial drone photo taken on June 18, 2026 shows a herd of yaks crossing a creek near the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Yang Zhisen)

An aerial drone photo taken on June 18, 2026 shows a herd of yaks passing through a culvert beneath the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)

Yaks pass through a culvert beneath the Qinghai-Xizang Railway in Seni District of Nagqu, southwest China's Xizang Autonomous Region, June 17, 2026. As the Qinghai-Xizang Railway stretches across the northern Tibetan Plateau, it has built not only dedicated wildlife crossings, but also many culverts and bridges to serve as ecological corridors for livestock such as cattle and sheep. (Xinhua/Jigme Dorje)