The number of terrestrial wildlife species in Beijing has increased from 608 to 612, including 519 bird species, the Beijing Municipal Forestry and Parks Bureau said Saturday.

The newly added four species are all birds, which are the black baza, the Oriental magpie-robin, the black-throated bushtit and the Himalayan cuckoo.

Located along the bird migration route between East Asia and Australasia, Beijing has been a frequent stop for many rare and endangered birds, such as the oriental stork, Chinese merganser and white-tailed sea eagle during this spring migration season, showcasing the ongoing ecological improvements in the Chinese capital, according to a staffer with the bureau.

Over the years, the city has strengthened the development of natural protected areas such as forests, wetlands and geological parks, creating a comprehensive system that effectively protects over 90 percent of its major wildlife and habitats.