Date of this Version
Jorgensen, Dinan, & Walker, “Snowy Owl Invasion of 2011–12,” from Nebraska Bird Review (June 2012) 80(2).
The Snowy Owl (Bubo scandiacus) is an Arctic breeder that regularly migrates to and winters in southern Canada and the northern United States (Parmalee 1992). The number of Snowy Owls moving south and the extent and timing of southward movements in any one year are believed to be dependent on interactions between populations of Snowy Owls and lemmings, the owls’ principal food resource (Parmalee 1992). Infrequently, relatively large numbers of Snowy Owls are observed in areas or regions where few are typically observed, and individuals are observed well south of the normal winter range. These occurrences are often referred to as “invasions” or “irruptions.”
The Snowy Owl is considered regular, albeit rare, in Nebraska (Sharpe et al. 2001) with a small number (< 5) reported annually or nearly so. Invasions have been noted in the past, such as in the winter of 1917–18 and the winter of 1954–55. As noted elsewhere, the winter of 2011–12 was a major invasion year and the first in Nebraska in which electronic media, such as Internet Listservs and email, improved communication and reporting of observations. The purpose of this note is to summarize the 2011–12 Snowy Owl invasion.