Eiders

[dhtu...@comcast.net]

Question at large. Have noticed a pair of white triangular pyramids on the backs of male common eiders, darker ones on the back of a king eider. Wondering what these units might be labeled in ornithological parlance, and their function, if any. They protrude an inch at most,  looking like misplaced ears. Thank in advance for any info!

Sent from my Verizon, Samsung Galaxy smartphone
Get Outlook for Android