Atop this entry are a few photographs of mourning doves spending time in my rooftop garden. As you can see, their eyelids are blue. This fact has often caused me to put a spin on an Elton John song ("Blue Eyes"), where part of the lyrics are:
Only when I see the mourning doves, I sing:
The fact that this bird type has blue eyelids is just one of their many fascinating features.
Cam (my female cardinal pictured below)
discusses many aspects of mourning doves in her book, Words In Our Beak Volume One, which is available in soft-cover format from MagCloud
and in digital format on Amazon as well as in Apple's iTunes and iBooks store.
But here are a few more facts that Cam might mot have mentioned in her narrative. According to WBF-MICH, Males mourning doves are larger than females and "show more color with a bluish cap" (as seen in the pictures below, which were also taken in my garden).
Another WBF-MICH Page states that "The Mourning Dove’s common name comes from their mournful cooing song. Their scientific name Zenaida honors Zenaide, Princess of Naples and the wife of Charles-Lucien Bonaparte, who was a naturalist and the nephew of the French emperor, Napoleon Bonaparte."
Their song may be mournful in its sound, but for the most part, mourning doves convey happiness as you might surmise from looking at the next image.
This dove tells me he identifies with Frank Sinatra's Old Blue Eyes, and like yours truly does with Elton John's song re blue eyes, "my" crooning mourning dove changes the song's words to suit his purposes, thus singing the words "Old Blue Eyelids...." whenever he hears the song.
ADENMENDUM: The digital versions of Volume One within the Words In Our Beak book series that are mentioned in this entry may only remain available for a limited time, but a hardcover version of Volume One can be found wherever books are sold.
Moreover, Volume Two of the book series is now available! Both volumes one and two are in hardcover format (as seen below) and can be purchased any place where books are sold.
Volume One: ISBN: 9780996378529:
Book Seller Info: http://bit.ly/2AFZDCz