As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Wednesday, 15 February 2017

Long-eared owls flock to Chicago in unusual irruption

Laura Pearson Chicago Tribune

An atypically high number of long-eared owls have swooped into Chicago this winter, their presence recorded by birders in birding databases and everyday residents on social media. According to various recent Facebook reports, a couple of fluffy, long-eared owls were spotted preening in Lincoln Park. Another darted in front of a delivery truck in Cicero. One sat on a barren tree branch outside of a Kohl's on Elston Avenue.

Skilled local photographers have captured these majestic, medium-sized birds on film: The distinctive patterning on their feathers, their orange facial discs and long ear tufts (not actual ears) make them look perpetually surprised.

A sudden upsurge of a single animal species in one area is called an "irruption." But what causes such a phenomenon, and how do long-eared owls adapt to city life? 

Pardon the irruption
It's not entirely clear where these long-eared owls flew in from, but Cornell Lab of Ornithology range maps show them breeding in the northern half of Wisconsin, northern Michigan, Minnesota and throughout Canada.

"Owls are irruptive migrants, meaning that where they show up and how many individuals are spotted during the winter can be somewhat unpredictable," says Stephanie Beilke, a conservation science associate with Great Lakes Audubon who studies, among other things, avian responses to urbanization and migratory stopovers. "Not much is currently known about what triggers an irruption, but it could be related to food availability and changes in population sizes."

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