Julie -
Good points and question about the southern die off of Siskins.
I do not know the answer to your question, but I bet the die off of Siskins to our south, happening first, just might indicate that warmer weather there could possibly be the culprit? I believe our die offs here didn't begin till the onset of our warm weather, thus exposing our birds to molds and such.
I have taken down my thistle feeder, cleaned up all the spillage and am offering Sunflower chips and whole sunflower that I step on to crack the husks, and offer them on two flat tray feeders. I still have over 40 Siskins regularly and I see no new sick birds so far. So far so good.
Dave Rosgen made a good point also to clean all our feeders with diluted bleach. As we feed the birds from the same feeders continually in one spot all winter, it is not natural, and the accumulation of husks and spillage under the feeders will eventually become a breeding ground for molds and disease, esp as it gets warmer.
I hope the Siskin population does not suffer from our seemingly good intentioned feedings, and they retain the numbers needed to have a successful breeding season. Lets hope.......
Paul Carrier -Harwinton