" It's really critical that the timing of this transition from feeding to migration be synched with other things happening in their habitats." The researchers think the seasonal change in singing patterns signals the start of migration.

“从觅食到迁徙的转变时间与它们栖息地发生的其他事情同步非常重要。”研究人员认为，歌唱模式的季节性变化标志着迁徙的开始。