On May 16th I headed over to Hurdman at lunch to search for some migrants. I only found 17 species in the hour I was there, and all but three were migrants. The first migrant was a Swamp Sparrow singing in the vegetation of a tiny, wet reedy patch that bore little resemblance to the cattail marshes in which they normally breed. The second was a Rose-breasted Grosbeak heard, but not seen, and while it is possible that they may breed here I have never come across any outside of migration. The third was a Black-and-white Warbler.
I first spotted this tiny songbird ambling along a branch just like a nuthatch. I started pishing, and it flew into to the shrub closest to me, trying to figure out what I was and what the strange sounds meant.
If it didn’t have the word “warbler” in its name, most people probably wouldn’t realize that this handsome black-and-white bird was in fact a member of the warbler family. For one thing, it has no brilliant hues of red, orange, yellow or blue anywhere on it. Warblers are renowned for their bright colours, from the breathtaking orange-flame hues of the Blackburnian Warbler to the blue and yellow tones of the Northern Parula, from the somber blue of the male Black-throated Blue Warbler to the Halloween colours of the American Redstart. The Black-and-white Warbler is black and white. Males can be distinguished by the large black stripe on its cheek; females have a plain white cheek.
Black-and-white Warblers also don’t act like other warblers when foraging for food. Rather than flitting through the tree tops, ducking behind leaves and picking larvae and caterpillars from underneath them, they walk along tree trunks and branches, probing in crevices with their slightly decurved bill. Their extra-long hind claws and heavier legs enable them to grip the bark and move in any direction they please, unlike Brown Creepers which can only move upward and nuthatches which typically move downward.
The Black-and-white Warbler is the only member of the genus Mniotilta – a name that means “moss-plucking,” which refers to its habit of probing bark and moss for insects.
They are more often heard than seen on their breeding grounds, their squeaky-wheel-going-round song giving away their presence. While they may be found in small and medium-sized woodlots and parks during migration, they normally breed in larger deciduous or mixed deciduous-coniferous forests across their range, building their round, open cup-shaped nests on the ground at the base of a tree, rock, stump, or fallen log. Occasionally Black-and-white Warblers build their nests in a cavity atop a tree stump, in a rock crevice, or on a mossy bank up to six feet high.
While Black-and-white Warblers live in Ottawa all summer long, I suspected this was a migrant as I have never found them singing or feeding young at Hurdman during the summer. When I do come across them during the summer breeding season, they are normally in larger forests such as the South March Conservation Area and Stony Swamp. Despite its lack of colour the Black-and-white Warbler is one of my favourite warblers, as I find its crisp two-toned plumage quite striking. Further, this species is much easier to watch them than other warblers, as they often forage in trees at human height instead of 20 feet up behind a screen of leaves. It also responds well to pishing, quickly flying in to check out the funny-sounding human and allowing excellent views.
This cooperative little bird was definitely the highlight of my visit. Though I’m sure to see and hear many more on my outings this summer, they are easier to see during migration, and this one was a treat to see up close.