Migration Mania #3: Black-and-white Warbler

Okay, those of you who are paying attention have already said, “Hey, wait, it’s not migration time yet! What are you trying to pull here?” And you are absolutely correct–migration is many weeks away. But there’s no reason we can’t daydream about pretty little birds to help us get through the depths of winter, right? So I’m picking up with my Migration Mania series early this year. You may have forgotten about this series because I started it in 2013 with two articles (here and here) and then neglected it last year. But I didn’t forget…aren’t you glad?

Black-and-white Warbler

So in this edition of Migration Mania I’m going to tell you a bit about the Black-and-white Warbler (Mniotilta varia). He’s unusual among warblers because he doesn’t wear any of the bright colors we usually think of in these birds — yellows, oranges, and blues. The BAWW (that’s cool birder-speak for Black-and-white Warbler) wears a bold graphic pattern of…wait for it…black and white!

And not only does he stand out for his appearance, but he’s got a different way of feeding than the other warblers too. Most of them forage for food around the leaves of trees and shrubs, but this guy spends a lot of his time on the trunk and branches, probing the bark for hidden goodies. This is how you normally see a nuthatch or a creeper feeding, not a warbler. It’s an advantage for those of us trying to take warbler photographs, because it’s easier to keep focused on a bird moving up a tree trunk than one that’s hopping over and under leaves at the speed of light (well, that’s how fast it seems sometimes…).

So where are the BAWWs now, while we’re freezing our tushies off up north? They’re down in Central and South America, that’s where. Places like Ecuador, Colombia, and Panama. Nice and warm, and plenty of food. You can see on this map that there are some of them in the southern U.S. now, but they’re probably not on the move yet. By early or mid-March we’ll start seeing some northerly movements though, and they’ll be off on their long journey to their breeding grounds in the U.S. and Canada.

eBird map of Black-and-white Warblers in January 2015

Since this species is one of the earliest to move northward in spring, some of them will already be nesting in April. It’s thought that they can come north earlier in the spring because of their ability to feed from the bark of trees–they don’t need the leaves to be opened before they come up here, like most of the other warblers. That’s a cool little fact to know, isn’t it? There are a few more fun facts below these photos.

Black-and-white Warbler

Black-and-white Warbler (2)

Fun facts:

  • These little birds weigh less than half an ounce and will fly an average of 20 miles each night during migration. Yes, that’s right, they migrate at night. As dawn breaks they drop down from the sky to feed so they’ll have energy to fly again the next night.
  • What do they eat? Butterflies, moths, ants, flies, bugs, click beetles, round-headed wood borers, leaf beetles, weevils, leafhoppers, plant lice, spiders, daddy longlegs, and more. Yum!
  •  The females build their nests on the ground, using dry leaves and grasses. The nest is usually at the base of a tree or beside a fallen log.
Black-and-white Warbler undertail
I love the pattern on his undertail coverts (the feathers that cover the base of his tail feathers).

I hope you enjoyed getting a closer look at one of my favorite warblers! And I hope you’ll be inspired to look for these adorable little birds when you’re outdoors this spring.

(Source for the stuff I didn’t know: Birds of North America Online from Cornell Lab of Ornithology.)


  1. My goodness!! I’ve never seen a BAWW but I’m going to be checking them out now. I wonder about when they might be moving through Oklahoma? During early spring here I find a LOT of unusual birds (for this area) in an area nearer the river. I can almost bet if I sit in this particular location I will sight anything moving through the area! Do I need to check out that map you have posted? Is there an accurate way of knowing where specific birds (species) are during migration?

    You get me all excited about birds! I might be poking around over at the river more this spring… hopefully before those darned snakes make their appearance!!


    • Yes, there’s a very good way to find the birds during migration (or any time of year). The real-time databases on eBird.org are free and available to the public. That’s where I enter my bird sightings. I just checked eBird reports for your area last year and the earliest BAWWs were in the last week of March. I’m going to email you with a map and some tips for finding what you want on eBird. And your idea of sitting beside the river is really good for finding migrating warblers!


    • I’m glad you liked it! I just checked eBird and there have been lots of sightings of Black-and-white Warblers in January in both the Phoenix and Tucson areas, so your chances of finding them are good!


  2. I like this warbler because it is easy to spot and track – just like you mention.
    Kim, did you perhaps miss a zero in the number of miles/night traveled by the BAWW? Twenty seems low.


    • Gail, I got that number from Birds of North America. They say 32 kilometers per night, and I converted it to miles. I know some warblers can and do fly much longer per day though. Maybe I’ll look into that for my next post in this series, thanks!


      • When I was confirming that number I found this too: “Also a trans-Gulf migrant, crossing the Gulf of Mexico to Central and South America, presumably covering the 1,000-km distance to earliest landfall on the Yucatán Peninsula in about 20–30 h of continuous flight.” So that’s 600 miles in a single flight, wowie!


  3. Thank you for this, Kim! It is wonderful to be thinking about — and anticipating — warblers and the Biggest Week in American Birding on a day when our region is experiencing a winter storm. Thanks, too, for the beautiful photos. I especially like the second one of the warbler peeking around the tree!


    • Glad to brighten your day, Judy! We’re supposed to get almost as much snow as you today, about 8-10 inches. It’s really starting to come down now…already a couple inches this morning. Stay warm and think warblers!


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