San Francisco birds sing differently in the pandemic

San Francisco birds sing differently in the pandemic

舊金山鳥類在疫情期間啼聲不同

【摘要2020.10.19.自由】◎陳成良

San Francisco birds started singing differently in the quiet of the coronavirus lockdown, says a study in Science.

《科學》期刊的一項研究稱，舊金山的鳥兒在安靜的冠狀病毒疫情封鎖期間，啼聲開始出現變化。

Before, urban white-crowned sparrow’s breeding territories were almost three times as loud as rural territories, the study found.

該研究發現，之前白冠麻雀在城內繁殖地區的啼聲音量是在鄉下的3倍。

But during the pandemic, researchers noted that noise levels in urban areas were drastically lower. In fact, they were consistent with traffic flow in the mid-1950s.

但是在大流行疫情期間，研究人員注意到，城區的噪音大大降低。事實上，這一噪音程度和1950年代中期的交通噪音程度相當。

Birds responded by producing higher performance songs at lower amplitudes, maximizing communication distance and salience.

鳥類的反應是用更低振幅唱出更優美的歌聲，從而最大程度地提高交流距離和顯著性。

"We found that birds sang more softly when noise levels were lower and at shorter recording distances before and during the shutdown," researchers said in the study.

研究人員在研究中說：「我們發現，當噪音程度較低時，鳥兒叫聲更輕柔。」

新聞辭典

consistent︰形容詞，前後一致的。例句：His behavior is consistent with his teaching.（他的行為與其教誨相符。）

amplitude：名詞，波幅；振幅。例句：The frequency and amplitude of vibration are monitored.（振動的頻率與振幅受到監控。）

salience：名詞，（指與正在發生或正被討論的事情）對…的重要性，與…的相關性。例句：The salience of these facts was questioned by several speakers.（這些因素的相關性受到幾位演講者的質疑。）