1.The scientists first played the birds two recorded sounds that they likely had never heard before. One was a warning cry of an allopatric chestnut-rumped thornbill, a bird not native to Australia. The other was a computer-generated bird sound called " buzz" .

科学家首先向鸟儿播放了两它们以前过的。一是异域的栗尾刺嘴莺的警告声，这鸟不是澳大利亚本土的。另一是电脑生成的" 嗡嗡" 鸟叫声。