COVID-19(新型冠状病毒肺炎)has cast a spell on the year 2020 and taken the world into a mess. There is no doubt that the COVID-19 has influenced human being's life in many (way) since its outbreak. But interestingly, according to the (late) science study, San Francisco birds start singing differently in the quiet of the COVID-19 shutdown. The study found that city birds were almost three times loud as village birds before, but the noise levels in city areas are much lower now. Because the shutdown, traffic flow in cities drops and people communicate less, which bring quiet living conditions.
These quiet are good news for bird populations. According to the research, birds have trouble (have) babies because of noise pollution. Noise can also lower birds' ability (hear) other birds' warnings of enemies and help calls from (they) own babies. Both of the reasons have likely played role in the drop of bird populations.
noise levels are lower, birds will be found sing more softly. Even though the birds sing more softly, the communication distance nearly doubled. Scientists believe more birds will be found flying in the sky in the near future!
