The Common redpoll is a widely distributed bird with several subspecies. It subsists on different seeds, mainly birch seeds. When these are absent or occur to a limited extent, it can migrate large distances. In some years, there may therefore be an "invasion" of Common redpolls, including in central Sweden where it otherwise does not breed. An example of how far a Common redpoll can migrate was shown last year in Ottenby on Öland, where a Common redpoll was captured that was already ringed - in China! When the redpolls arrive, they look for birch seeds and elm seeds. But the occasional sunflower seed also slips down. In certain years, this makes it one of our most common birds at the feeders...