Kimimori SARASHINA, a researcher of a native town wrote in his book entitled "Hikaru tori, Hitodama, Hibashira" (shining bird, disembodied soul, pillar of fire) about many firsthand accounts of those grey herons and young night herons shining in pale blue like aosagibi (blue heron fire), including a story in which a young night heron was seen to shine in pale blue in Ibaraki Prefecture in around 1928.
郷土研究家・更科公護の著書『光る鳥・人魂・火柱』にも、昭和3年頃に茨城県でゴイサギが青白く光って見えた話など、青鷺火のように青白く光るアオサギ、ゴイサギの多くの目撃談が述べられている。