Wednesday, February 15, 2012

East-west migrations: Varied Thrush



Most people are used to the "normal" migration routes taken by many birds. This does apply to many bird species in North America. They migrate north in the spring to their summer breeding grounds and then migrate south in the fall to their southern wintering grounds.  In this ongoing blog series, I will be talking about some of the slightly less known migrants. Those that migrate from west to east and vice versa.

A number of species have been known and documented to migrate from their western summering grounds to wintering grounds in the eastern part of the country.  Included in this group are some surprising species that you might not expect. Birds like White-crowned and White-throated Sparrows, several species of western hummingbirds, many of our eastern wood-warblers, Townsend's Solitaires, Vaux's Swifts, Varied Thrush and others.  In this post, I will detail some of the migration patterns of Varied Thrush.

 Let's start with the bird itself:
Varied Thrush (ixoreous naevius).    
The word "varied" of course referring to the striking gray, black and orange plumage.
"ixoreous"means "belonging to mistletoe." Reference is to this bird's resemblance to the old world Mistle Thrush.  "naevius" is used to imply varied and is used in reference to the bird's plumage.

Isn't this an awesome-looking bird?


Varied Thrush has a summer range that stretches from the mountains of northern California, all the way up to the Arctic Circle in Alaska. Throughout breeding season, their haunting trilled songs can be heard echoing through the rainforests of the Pacific Northwest.  In winter, most field guides will tell you that while they can be found year-round in Washington and Oregon, a portion of the population heads south into central California to winter in the hills around the central valley. 
However, there is another wintering area that is not mentioned in most field guides.  It is an extra-limital wintering area: The Eastern US.  The numbers are small, but the birds are certainly present. Every year, Varied Thrushes are found in small numbers across the upper and lower midwest and partly into the east.  

Here in Wisconsin, we don't require documentation for Varied Thrush because they show up in the state in small numbers every year. The same goes for Minnesota, although, they do require documentation. Interestingly, Michigan, Illinois and Indiana also require documentation for Varied Thrush sightings.  

The birds are starting to show up more regularly though and it's only a matter of time before they're found in these states on a regular basis. 

Varied Thrushes are one of my favorite birds of the temperate rainforests of the northwest. The haunting, trilled song floats through the patchy, mist-filled spots of sunlight that filter down through the redwoods and sequoias. They are often hard to see, sitting in the tall, dense-foliaged trees, but you'll never miss their song.  

6 comments:

David Bell said...

Interesting post, however Varied Thrush is not on the Michigan review list!

Chris W said...

Thanks for the clarification! Someone had told me that it was and I kind of took their word for it.
That's good though. MN still has it on and they get more VATHs than we do!

sarah said...

What a unique bird

sarah said...

I like the color variation of the bird

Tiara said...

Fantastic!

Shelinwa said...

I live in WA state by the canadian boarder and we have a family of these in our back year. We have never seen these before. So looking around to see wht here/now.