The Chestnut-sided Warbler in Fall Attire
Roger Tory Peterson was the first to coin the phrase “Confusing Fall Warblers” in his Field GuideTo the Birds first published in 1934 and devoted separate pages depicting those birds and pointing with arrows the significant points to look for during the fall migration. John Dunn in his Field Guide to Warblers of North America (Peterson Field Guide Series-1997) states: “Despite the fearsome concept of “confusing fall warblers” the identification is generally straightforward given adequate views”. Before fall migration, many species of warblers lose their bright and distinctive spring plumage and molt into duller or drab colors for the winter months.
So how does the new birder identify warblers in the fall? First remember that there are basic features such as wing bars that help to identify the warbler in any plumage, then there is habitat preference, the Common Yellowthroat likes marsh and other wet habitats; the Wilson’s and Canada warblers tend to be found low in thick shrubbery and many others prefer the tops of trees- exactly like they do in the spring. Watch for distinctive behavior, the American Redstart always fans its tail, the Palm and Prairie warblers raise their tails. Warblers rarely sing in the fall so you need to familiarize the call notes or chips they make, this is a bit more difficult but it easy to start with the Yellow-rump’s fairly distinctive loud “check” call. One warbler species-the Chestnut-sided has a very different look in the fall; I like to call it the Lemon and Lime Warbler. Gone are the bright chestnut sides, gone is the yellow cap, a beginner would probably never think of a Chestnut-sided.
During the fall migration theMountAuburnbirder is challenged in finding and getting good looks at these confusing fall warblers. First of all they don’t sing in the fall, the trees are still in heavy dark foliage and they tend to stay high in the trees. At Mount Auburn the Butterfly Garden at Willow Pond and the Wildflower Meadow by Washington Tower are good places to look for warblers at ground level, many birds are attracted to the seeds of the old flower heads as well as the many insects that the goldenrods and asters attract.