September Bird of the Month: Black-and-white Warbler

In today's post, Nathan Martineau writes about the Black-and-white Warbler, a bird that can easily be found at Fenner right now. Come to Fenner to see it yourself!

The month of September brings the opportunity to see many birds during their fall migration here at Fenner--including the Black-and-white Warbler (Mniotilta varia). Also, this month the Capital Area Audubon Society is leading Fall Migration Bird Walks here at Fenner on Saturdays (9-11am), which is another great opportunity!

The Black-and-white is different from other warblers because first, it is one of the few members of its family that does not change appearance between spring and fall, while the others transform from their bright spring plumage into "LBJs" or "little brown jobs." In fall, these"LBJs" are quite dully colored and similarly patterned and sometimes prove an extreme challenge to identify by species. 

Secondly, the Black-and-white Warbler has a very unique habit of hitching up and down tree trunks and branches while foraging for food, quite like a woodpecker or a nuthatch would do. Only one other species of warbler exhibits this behavior (the Prothonotary Warbler if you are curious), and even they only do it occasionally. 

Male

Female

The Black-and-white, as well as other warblers, can be found in any wooded setting throughout the park in migration, although the migrant birds tend to concentrate around the Woodland and Field Ponds, and the parking lot.  This may not be true on some days, though, as migration is always hit-or-miss and each day is different. Black-and-whites can be very common on a good migration day. They can be found here from late April through late May and again from September to early October.