Researchers in Russia investigated the map issue in a past study by capturing Eurasian reed warblers on the Baltic Sea as they flew northeast towards their breeding grounds near Saint Petersburg.

曾进行的一项研究中俄罗斯科学家们通过抓获在波罗的海飞往东北部圣彼得堡附近繁殖地时欧亚芦苇莺对候鸟们所使用的地图进行了调查。