Hi Anne. Great questions. Don't know about redpolls but I just read today ( Sibley's "What Its Like To Be A Bird") that with chickadees the birds, themselves, can tell make from female because the black bib on the males fluoresce more deeply than on the female. Trouble is, THAT is something OUR brains aren't wired to see. Pete
On Sun, Mar 14, 2021, 10:34 AM <anneb.cl...@gmail.com> wrote: > This winter my first- ever redpoll flock has been eating niger almost > faster than I can stock it. They do NOT like the fancy finch mix, their > bill flips have informed me. > > So I have been looking at the wild differences in cap and breast and belly > colors. The caps are a distinctly more classic red, while rest can be deep > rose. > But the caps! I will bet that their red caps fluoresce in the daylight > UV, intensifying the “brightness”. This is what budgie yellow caps- in > exactly that area of feathers-do. Just the cap, not a whole yellow head. > > Anyone? Testable with UV lamp and maybe Collections specimens? > Fluorescence in the visible range will be spectacular. Budgies look like > miners with little head lamps. > > Also note. Like budgies, the caps/polls do not differentiate males and > females. I think accentuating them helps detect flock mate scanning and > flying during flock foraging. > > I am probably wrong but would love to know. > Anne > > Sent from my iPhone > -- > > Cayugabirds-L List Info: > http://www.NortheastBirding.com/CayugabirdsWELCOME > http://www.NortheastBirding.com/CayugabirdsRULES > http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm > > ARCHIVES: > 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html > 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds > 3) http://birdingonthe.net/mailinglists/CAYU.html > > Please submit your observations to eBird: > http://ebird.org/content/ebird/ > > -- > > -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
