What makes these little birds willing to ignore the noise and vibration, endure the black, noxious exhaust fumes, and become street urchins, building their nests and raising their young along narrow mountain roads where pedestrians fear to tread and their lives appear constantly in danger?
是什麼原因，讓栗背林鴝無視噪音震動，願意承受烏煙瘴氣，選擇在行人都難以忍受、生命深感威脅的狹窄山路旁據地築巢、撫育後代，成了馬路小天使？