Common Redpolls are small finches that usually reside in the Arctic regions. However, when their food sources that most often consist of seeds found in the catkins of birch trees and alders and in clusters on various herbaceous plants become scarce in the winter they will head south in search of these or alternative seeds. That is happening right now. It is not an invasion yet, but fair numbers are showing up in New England, New York, and New Jersey. We had our first one of the year at White Memorial on Thursday, the 20th. It didn't stay long around the Museum and Office Feeders. Today (the 22nd) we have at least 4 around the Main Area. They are spending most of their time flying around. This is a good way to spot them, as they are very vocal in flight. Their call sounds like "chet-chet-chet", and is frequently repeated. They have settled into the maple tree right behind the Museum deck, but only perched there for 2 minutes. Since they really like black oil sunflower seed we hope that they will eventually spend some time on the feeders. At my house in Winchester I've had up to 25 redpolls at one time this past week. Two of them have been regular visitors to the feeders for several hours each day. Besides feeders it is also worth looking for these birds in stands of birch trees.