Yancheng is home to 436 bird species, accounting for 30. 17% of the total bird species found in the country. It hosts 117 rare and endangered bird species, 37 of which are listed as threatened on the IUCN Red List. The Milu deer population here has risen to 7,840, representing 70% of the global count.

Two of the world's most endangered migratory birds, the Spoon-billed Sandpiper and the greenshank, rely on this habitat for their survival.

The Spoon-billed Sandpiper, often playfully referred to as the “little spoon”, gets its name from its uniquely shaped beak that resembles a spoon. With a global population of barely 250 pairs, it ranks among the world's most endangered migratory birds. These sandpipers breed in northeastern Siberia, and annually, over half of them journey to the Yellow Sea wetlands. They reside here for 3-4 months, engaging in activities like feeding and molting, during their migratory passage from south to north.

The red-crowned crane  holds a special place in oriental culture, often revered as the crane of immortality. Every winter, between 600-800 of these majestic birds migrate to Yancheng's Yellow Sea wetlands, which constitute 40%-55% of the global wild population. Thus, Yancheng has earned the title of the second hometown of the red-crowned crane and stands as the largest wintering ground for this species worldwide.

The Milu deer is a globally rare species belonging to the deer family. Its unique features include a horse-like head and face, deer-like antlers, cow-like hooves, and a donkey-like tail. Despite these similarities, it distinctly stands apart from all these animals, making it quite the "odd one out". Today, with a population exceeding 7,000 in Yancheng, this region has become the world's most significant gene pool for this species.