This Common Redpoll, which I photographed on Nov 8, 2012 in Steel Canyon, Cache Co., was among the first of the irruption, a sign of things to come.

This year has been absolutely unprecedented for Common Redpolls in Utah, at least as far back as records have been kept.  For a sense of the scale of this irruption, here are all the eBird records from 1900 to 2011:

And here are the eBird records from just the last three months:

Large flocks have been documented in Utah before: for example, 120 were seen in the 1988 Christmas Bird Count in Kanab, and a flock of 40 was reported in Duchesne County in 1958.  But this is certainly the best-documented irruption of them in the state, and perhaps the largest.  Birds like these irrupt from the north when their seed crops fail and they must wander further south than usual to find sufficient food.  You can help document this irruption into Utah by submitting your records to eBird (a photo or a thorough description in the comments field always helps), and by submitting records to the Utah Bird Records Committee.  But most importantly, get out and enjoy this experience, which might be a once-in-a-lifetime event!  A thistle feeder is a good way to bring this species to your yard, but they will also come to other kinds of seed.  They are also particularly fond of birches and wild thistle, so watch for these plants near your favorite birding spots.