I recall large rafts of Redheads in winter along the cottages north of East Shore Park in the mid-1980s, and I think that was before the Zebra Mussel invasion which began in the Great Lakes in 1988. I wasn't counting numbers then (nor am I much good at it now), but that was my first experience with such extensive and densely packed duck rafts. The Aythya numbers could well have increased significantly since Zebra Mussels changed the ecology.
--Dave Nutter On Jan 25, 2015, at 09:14 PM, "Kenneth V. Rosenberg" <k...@cornell.edu> wrote: > My understanding is that the large flocks of Aythya ducks are related to the > proliferation of exotic zebra mussels in the Finger Lakes- but I have to > admit that I don't know the details or whether the different species feed on > them to a different extent. > > Ken > > Sent from my iPhone > > On Jan 25, 2015, at 8:55 PM, "Brad Walker" <bm...@cornell.edu> wrote: > >> Hi all, >> >> It's only one species, but last year I prepared round skin of a REDHEAD that >> had been found dead on Cayuga Lake, off of Hog Hole. It's stomach was filled >> with an assortment of small mussels. >> >> I took a few photos of them if anyone is interested. >> >> - Brad >> >> >> Brad Walker >> Media Specialist >> Macaulay Library >> Cornell Lab of Ornithology >> 159 Sapsucker Woods Road >> Ithaca, NY 14850 >> >> 607-254-2168 >> >> On Sun, Jan 25, 2015 at 8:47 PM, Benjamin Freeman <bg...@cornell.edu> wrote: >> >> Hello all, >> >> Alexa and I had the good fortune to watch the Tufted Duck for an hour or >> so on Saturday morning. It was diving actively the entire time, which made >> it tough to find (and difficult to show to others in the scope). Which got >> me thinking: What are the various Aythya eating? The Tufted Duck was clearly >> associating with scaup on Saturday that were actively feeding. Also present >> were several big flocks of Redhead (all loafing around), and a decently big >> group of Canvasback (also loafing). >> >> A quick search informs me that Aythya eat gastropods, mussels and >> aquatic vegetation among other things, and that the relative proportion of >> animal food in their diet varies seasonally. >> >> Does anyone know what they are eating in Cayuga in winter? Must be a >> fair bit of food to support so many birds for several months... >> >> Do different species of Aythya eat different things? >> >> Can you tell when Aythya are eating gastropods/molluscs/animal food vs >> plants based on their diving behavior? >> >> Looking forward to learning what these ducks are up to, >> >> Ben >> >> -- >> Benjamin Freeman >> Ph.D. candidate >> Department of Ecology and Evolutionary Biology >> Cornell University >> Ithaca, NY, USA >> benjamingfreeman.com >> >> -- >> Cayugabirds-L List Info: >> Welcome and Basics >> >> Rules and Information >> >> Subscribe, Configuration and Leave >> >> Archives: >> The Mail Archive >> >> Surfbirds >> >> BirdingOnThe.Net >> >> Please submit your observations to eBird! >> -- >> >> >> -- >> Cayugabirds-L List Info: >> Welcome and Basics >> >> Rules and Information >> >> Subscribe, Configuration and Leave >> >> Archives: >> The Mail Archive >> >> Surfbirds >> >> BirdingOnThe.Net >> >> Please submit your observations to eBird! >> -- > -- > Cayugabirds-L List Info: > Welcome and Basics > > Rules and Information > > Subscribe, Configuration and Leave > > Archives: > The Mail Archive > > Surfbirds > > BirdingOnThe.Net > > Please submit your observations to 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/ --
