Two Winters are never the same in birding the Sioux Falls area. One year many individuals of a rare species or two will show up for most of the Winter: an irruption. The next Winter it will be a different species. Perhaps the best example is the Winter of 2011-12 compared to 2012-13. Snowy Owls provided a historic irruption where 20-30 birds were being seen in a single day. In 2012-13, few owls were seen, but hundreds of Common Redpolls, with some rare Hoary Redpolls and hundreds of Pine Siskins were observed in the area; another historic irruption. In the fall and early winter of 2007, Long Eared Owls were seen 25 in a day.
Snowy Owl irruption 2011-12