I am not sure what specific berries we lacked during winter that would contribute, but of course, purple finches and house finches could have been influenced by diets south of here.
On the other hand, it appears that carotenoids that end up purple-red are the result of conversion of yellower pigments into purple or, in other species, cardinal-red. Here is a news report on a few papers cited at the bottom: https://phys.org/news/2016-05-genes-enable-birds-red.html Genetic differences (defects perhaps) can result in yellow cardinals and perhaps the yellow-orange of finches. Even in the classic house finch story, Kevin McGraw and others have shown that differences between males are not just dietary, but result from their genetically influenced abilities to sequester and then push the carotenoids into their feathers. Conversions within carotenoid biochemical structures happen along the way, so that different species eating similar carotenoids end up with different plumage color. So the simple idea that brighter males were better at gathering carotenoid-rich foods turns out to be too simple. And females sharing these “sequester more carotenoid” genes put more into their egg yolks, which may protect rapidly growing embryos from free radicals. Now—why one would suddenly get some genetically odd purple and house finches in the same spring…I have no idea! And this is probably way more than anyone wanted to know! Anne Current Biology, Lopes, Johnson, and Toomey et al.: "Genetic Basis for Red Coloration in Birds" www.cell.com/current-biology/fulltext/S0960-9822(16)30401-8 <http://www.cell.com/current-biology/fulltext/S0960-9822%2816%2930401-8> / dx.doi.org/10.1016/j.cub.2016.03.076 <http://dx.doi.org/10.1016/j.cub.2016.03.076> Current Biology, Mundy and Stapley et al.: "Red Ketocarotenoid Pigmentation in the Zebra Finch Is Controlled by a Cytochrome P450 Gene Cluster" www.cell.com/current-biology/fulltext/S0960-9822(16)30400-6 <http://www.cell.com/current-biology/fulltext/S0960-9822%2816%2930400-6> / dx.doi.org/10.1016/j.cub.2016.04.047 <http://dx.doi.org/10.1016/j.cub.2016.04.047> Read more at: https://phys.org/news/2016-05-genes-enable-birds-red.html#jCp <https://phys.org/news/2016-05-genes-enable-birds-red.html#jCp> Current Biology, Lopes, Johnson, and Toomey et al.: "Genetic Basis for Red Coloration in Birds" www.cell.com/current-biology/fulltext/S0960-9822(16)30401-8 <http://www.cell.com/current-biology/fulltext/S0960-9822%2816%2930401-8> / dx.doi.org/10.1016/j.cub.2016.03.076 <http://dx.doi.org/10.1016/j.cub.2016.03.076> Current Biology, Mundy and Stapley et al.: "Red Ketocarotenoid Pigmentation in the Zebra Finch Is Controlled by a Cytochrome P450 Gene Cluster" www.cell.com/current-biology/fulltext/S0960-9822(16)30400-6 <http://www.cell.com/current-biology/fulltext/S0960-9822%2816%2930400-6> / dx.doi.org/10.1016/j.cub.2016.04.047 <http://dx.doi.org/10.1016/j.cub.2016.04.047> Read more at: https://phys.org/news/2016-05-genes-enable-birds-red.html#jCp <https://phys.org/news/2016-05-genes-enable-birds-red.html#jCp> Anne B Clark 147 Hile School Rd Freeville, NY 13068 607-222-0905 anneb.cl...@gmail.com > On May 5, 2017, at 6:17 PM, Linda Orkin <wingmagi...@gmail.com> wrote: > > I would imagine no one can be surprised at poor condition in these birds this > year with the dearth of carotenoid source fruits and berries over this past > fall and winter. This would not be permanent but could be corrected with > better diet, correct Kevin? > > Thx > > Linda Orkin > > Sent from my iPhone > > On May 5, 2017, at 5:23 PM, Kevin J. McGowan <k...@cornell.edu > <mailto:k...@cornell.edu>> wrote: > >> No, the most likely explanation is that it is a young male in relatively >> poor condition. The captive experiments showed that poor diet makes for more >> yellow and less red birds. Those ideas apply to wild birds, as well. >> Yellowish House Finches are relatively common. I usually see a few each year. >> >> >> But, since you brought up the topic. I had occasion the other day to see the >> same phenomenon (I am guessing) in PURPLE Finches, which I don't think I've >> ever seen before. Photos of a yellowish male coming to my feeder can be seen >> at https://ebird.org/ebird/view/checklist/S35976663 >> <https://ebird.org/ebird/view/checklist/S35976663>. >> >> >> Best, >> >> >> Kevin >> >> >> >> Kevin J. McGowan >> Project Manager >> Distance Learning in Bird Biology >> Cornell Lab of Ornithology >> 159 Sapsucker Woods Road >> Ithaca, NY 14850 >> k...@cornell.edu <mailto:k...@cornell.edu> >> 607-254-2452 >> >> >> From: bounce-121504884-3493...@list.cornell.edu >> <mailto:bounce-121504884-3493...@list.cornell.edu> >> <bounce-121504884-3493...@list.cornell.edu >> <mailto:bounce-121504884-3493...@list.cornell.edu>> on behalf of W. Larry >> Hymes <w...@cornell.edu <mailto:w...@cornell.edu>> >> Sent: Friday, May 5, 2017 4:53 PM >> To: CAYUGABIRDS-L >> Subject: [cayugabirds-l] Further info Yellow House Finch >> >> Upon reading the literature, it appears that captive house finches can >> have yellow coloration because of the lack of carotenoids in their >> diet. Would the most likely explanation for this particular bird be >> that it escaped from captivity? >> >> Larry >> >> -- >> >> ================================ >> W. Larry Hymes >> 120 Vine Street, Ithaca, NY 14850 >> (H) 607-277-0759, w...@cornell.edu <mailto:w...@cornell.edu> >> ================================ >> >> >> -- >> >> Cayugabirds-L List Info: >> http://www.NortheastBirding.com/CayugabirdsWELCOME >> <http://www.northeastbirding.com/CayugabirdsWELCOME> >> http://www.NortheastBirding.com/CayugabirdsRULES >> <http://www.northeastbirding.com/CayugabirdsRULES> >> http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm >> <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> >> Cayugabirds-L Subscribe, Configuration, and Leave Instructions >> <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> >> www.northeastbirding.com <http://www.northeastbirding.com/> >> Cayugabirds-L – Subscribe, Configuration and Leave . Cayugabirds-L is an >> email list (the List) focused on the discussion of birds and birding in the >> Finger Lakes ... >> >> >> ARCHIVES: >> 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html >> <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> >> cayugabirds-l - The Mail Archive >> <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> >> www.mail-archive.com <http://www.mail-archive.com/> >> cayugabirds-l Thread; Date ; Earlier messages; Messages by Date 2017/04/25 >> [cayugabirds-l] the colors of spring Melanie Uhlir >> >> 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds >> <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> >> 3) http://birdingonthe.net/mailinglists/CAYU.html >> <http://birdingonthe.net/mailinglists/CAYU.html> >> >> Please submit your observations to eBird: >> http://ebird.org/content/ebird/ <http://ebird.org/content/ebird/> >> <http://ebird.org/content/ebird/> >> eBird <http://ebird.org/content/ebird/> >> ebird.org <http://ebird.org/> >> Please join us in congratulating Chris McCreedy of Tucson, Arizona, winner >> of the March 2017 eBird Challenge, sponsored by Carl Zeiss Sports Optics. >> >> >> -- >> -- >> Cayugabirds-L List Info: >> Welcome and Basics <http://www.northeastbirding.com/CayugabirdsWELCOME> >> Rules and Information <http://www.northeastbirding.com/CayugabirdsRULES> >> Subscribe, Configuration and Leave >> <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> >> Archives: >> The Mail Archive >> <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> >> Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> >> BirdingOnThe.Net <http://birdingonthe.net/mailinglists/CAYU.html> >> Please submit your observations to eBird <http://ebird.org/content/ebird/>! >> -- > -- > Cayugabirds-L List Info: > Welcome and Basics <http://www.northeastbirding.com/CayugabirdsWELCOME> > Rules and Information <http://www.northeastbirding.com/CayugabirdsRULES> > Subscribe, Configuration and Leave > <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> > Archives: > The Mail Archive > <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> > Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> > BirdingOnThe.Net <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/ --
