Blackpoll Warbler

Dramatic Plumage Change in the Fall

Blackpoll Warbler in Breeding Plumage

The Blackpoll Warbler (Setophaga striata) is a warbler species which undergoes a big plumage change twice yearly; into its breeding plumage and into its non-breeding (alternate) plumage.  The change is so dramatic it is difficult to recognize it as the same bird.

Shown above is the male Blackpoll Warbler in breeding plumage.  This is what it looks like when it arrives here in the spring.  Note the black cap extending through the eyes, white cheek and black malar (cheek) line.  The back is black-streaked on warm grey; the sides are heavily streaked in black and the underparts are white.  There are two white wing bars and the feet, legs and bill are yellowish.

Blackpoll Warbler in Alternate Plumage [N. Geographic Complete Birds of N America p. 539]

And, as you can see above, the fall Blackpoll Warbler looks vastly different. The back is a dull olive green with black streaks.  The underparts are white with yellow streaks on the sides.  There is white under the tail.  The face is yellow with a dark streak through the eye.  It has the same two white wing bars.  Even the legs have turned dark!  

Now you can see why fall warbler birding is difficult!  But how does this little bird change so dramatically?  I recently was shown photographically by a good birding/blogging friend who has kindly given me permission to use her photos.  She has luckily photographed a Blackpoll Warbler in the transition stage.

Blackpoll Warbler [Lisa de Leon Photo]

Blackpoll Warbler [Lisa de Leon Photo]

These photos above show how this bird changes its plumage from breeding to fall (alternate) plumages.  It must do it quite quickly because we seldom see birds in transition like this.  If you had a fall-plumaged bird in hand you could tell for sure it was a Blackpoll because it retains the yellow soles on its feet.

The Blackpoll Warbler breeds in the summer in the Maritimes and throughout most of northern Canada to Yukon and Alaska.  It migrates southward in the fall eastward and then south either down the eastern US or to the Maritimes and south directly over the Atlantic Ocean to the Caribbean Islands and South America where it winters.  This amazing latter flight route averages 1864 miles over water!  That would require a non-stop flight of approximately 88 hours (Ibird Pro).  In order to do this, this species needs to double its weight by feeding heavily here in our province on insects in August and September where we have plenty of suitable habitat.  A remarkable species indeed!