阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
Beijing is the capital city of China. It (cover) an area of around 17, 000 square kilometers, in which there are different kinds of bird habitats (栖息地), (include) grassland, scrubland (灌木丛林地), wetland, and also agricultural land. Researchers call these areas "service stations," where migrating (迁徙) birds stop (rest) and feed. But the birds ‘"service stations" re (rapid) closing in Beijing, as the city considers scrubland, grassland and old agricultural land to be "dirty" and "ugly".
The loss of grassland and scrubland is already having a major influence Beijing's bird life. In the north of Beijing, the land around Miyun used to be visited by thousands of cranes (鹤). Now, much of that land is covered with man-made forest and number of cranes there has greatly fallen.
"Cranes are rare and valuable animals in China. At Miyun, a festival (hold) to celebrate the migration of cranes every year," one researcher, Townshend, says. "Because it is Beijing, we can attract many people—both local people visitors."
"More cooperation (合作) between (country) is needed," Townshend adds. "Migratory birds are a shared natural heritage (遗产), and with this comes a common (responsible) to protect them and the places they need," he says.