Background: In the past decades, birdwatching as a hobby developed rapidly and produced ample scientific records that have aided conservation efforts. Therefore, it is increasingly attractive to promote avian research by providing data from birdwatching. Methods: We compared records from 16 years of community birdwatching and a 1-year formalized bird monitoring in Suzhou, China to study the similarities and differences between the two monitoring methods. Results: We showed that within the 325 bird species recorded by the two methods, an annual average of 108 species were documented by community science and 223 bird species were recorded by 1-year formalized monitoring. Measured by the number of bird species recorded per survey trip, the bird monitoring activity of community birdwatchers was significantly lower. Furthermore, the monitoring intensity of community birdwatching measured as the average survey trips per site each survey year was also lower than that of formalized bird monitoring. In addition, community birdwatchers preferred urban landscapes to rural areas. Conclusions: Community birdwatching could record the majority of local birds and complements the professional surveys in avian research. Well designed and coordinated community science can be used to expand the knowledge about avian distribution and population dynamics. These findings are critical for the development of conservation science with regard to community involvement.