Species Profile:
Common Yellowthroat

Witchity, witchity, witchity, witch! The distinctive call of the Common Yellowthroat (Geothlypis trichas) makes it one of the first warblers that beginning birders can identify by song alone. But few can lay claim to such a dramatic encounter with this bird and its song as Michael Mesure, President of the Fatal Light Awareness Program.

Early on in his bird rescue career Michael caught a disoriented but seemingly healthy male Common Yellowthroat in downtown Toronto and did the usual thing of popping him into a brown paper bag. As Mike drove to the release site, the yellowthroat nudged his way out of the bag and proceeded to fly around the car. Before Mike could pull the car over, the bird had landed on the rear view mirror. Michael stopped the car and watched, mesmerized, as the yellowthroat began to sing, singing for all he was worth, then dropped into Mike's lap, dead.

This incredible experience cemented his dedication to the plight of migratory birds. It's no accident, either, that Michael chose the Common Yellowthroat as the avian representative for the FLAP logo.

The stunning black mask of the male makes the Common Yellowthroat the Lone Ranger of the bird world! The female lacks the mask but is otherwise similar in appearance to her mate with a bright yellow throat, whitish belly and olive-brown back, wings and tail. The wren-like jerky movements with tail cocked upwards earned the bird the early moniker of "Olive-coloured Yellow-throated Wren". In 1907 ornithologist Frank Chapman wrote: "With nervous animation the bird hops here and there, appearing and disappearing, its bright eyes shining through its black mask, its personality so distinct, that one is tempted to believe it is a feather-clad sprite of the bushes."

Like other warblers, the yellowthroat eats insects and lots of them! One individual was seen to pack away 89 aphids in one minute! And feeding is an activity requiring such intense concentration that even the threat of capture may not divert a Common Yellowthroat from its goal. Michael tells the story of a male yellowthroat intent on catching a moth. He walked up and grabbed the bird, but even from his grasp the bird stretched out his neck, snatched the moth and swallowed it!

Other preferred snacks of Common Yellowthroats include spiders, beetles, flies and their larvae. But the birds themselves can become food for larger creatures. One hapless fellow was found in the stomach of a three-pound Largemouth Bass!

One of the most abundant of North American warblers, the Common Yellowthroat prefers marshy or scrubby wet areas as nesting sites. The nest is a cup of grasses and rootlets lined with finer material, usually located on or close to the ground, but above the high water mark.

The Song Sparrow, Yellow Warbler and Common Yellowthroat are the three birds most commonly parasitized by the Brown-Headed Cowbird. The cowbird's chick-raising strategy is to let someone else do the work, depositing her egg in another species' nest. The host bird often cannot distinguish this foreign egg from her own and will incubate and feed the alien nestling, frequently to the detriment of her own offspring. The Common Yellowthroat will sometimes refuse to be the adoptive parent, however, and actually build another nest on top of the intruding cowbird egg!

Clever though it may be, the Common Yellowthroat still falls victim to the lights of tall structures far too often (it's the second most common warbler that FLAPPERs find on Toronto's darkened streets). So we continue our struggle to make urban environments safer for this lovely songbird and many others.

Chris Earley
Chris is the Interpretive Naturalist at the Arboretum, University of Guelph and author of Warblers of Ontario.