Bird diversity has declined as native birds have avoided using the green desert after the Smooth Cordgrass Spartina alterniflora invaded coastal China. After many years of coexistence, a few passerine birds began to enter and use Smooth Cordgrass, but only birds of nonspecialised habitat. In this study, we first found that a native reed-specific bird, the Parrotbill Calamornis heudei, flocked and sang in a Smooth Cordgrass habitat in the whole overwintering period near Sheyang Port in Yancheng, Jiangsu Province. This phenomenon indicates that native obligate birds may be forced to adapt to exotic Smooth Cordgrass habitats after long-term coexistence; obviously, the distribution, feeding and reproduction of birds would be affected. Is this an ecological trap? Which may lead to unknown ecological consequences. We suggest that more research attention should be given to this process occurring along the Chinese coast.