Female bluebirds sing to strengthen and maintain the bond with their mates.
International Dawn Chorus Day: Why do birds sing in the morning? - The Future Forest Company
Nature's Symphony – Why Birds Sing and What it Means – Johnston & Jeff
CuriouSTEM - Why do birds sing?
Has the Biggest Week in American Birding been canceled?
fairy-wren Archives - Australian Geographic
Study reveals gender bias in bird song research and impact of women on science
Has the Biggest Week in American Birding been canceled?
Female birds that used to be silent are now singing like males
Why Do Female Birds Sing?