Posted by Bob Lefebvre
Brown Thrashers are rather late migrants, usually arriving in the Calgary area in mid-May or even late May, as do their Gray Catbird cousins. The bird shown here was one that actually overwintered here this year. It was first noticed before Christmas 2016 in Airdrie by Heinrich Lohmann.
Brown Thrasher, Airdrie, January 16, 2017. Photo by Heinrich Lohmann.
The bird was coming to a feeder in Heinrich’s yard and continued to do so into March of this year. The photo below was taken on March 10th, and the bird was last seen on March 11th. It may have moved on to its summer territory then, getting a big jump on its migratory rivals (although if so, it will have a bit of wait for any females to arrive back).
Brown Thrasher, Airdrie, March 10, 2017. Photo by Heinrich Lohmann.
It’s not unheard-of for Brown Thrashers to overwinter in Alberta. One was seen in Calgary in December 2015 and (I believe) one in Canmore later that winter. One was seen north of Edmonton in February 2015. Of course, these birds are at high risk when spending the winter so far north. Their normal winter range is in the SE United States. As I said, a bird that successfully overwinters here will get first choice of breeding territories. But it’s also possible that birds that overwinter are only doing so because they were sick or injured during the migration period, and were unable to head south.
In any case it’s always interesting to see a “summer” bird here in mid-winter.