Wayne R. Petersen
As Bird Observer kicks off 2021, readers are undoubtedly hopeful and optimistic that the new year will be better than 2020 in every way possible. How could it be worse, you might ask? With this optimistic forecast in mind, and depending upon your birding experience or birding skill, this issue’s At A Glance challenge may cause you to think twice about this as you consider the identification of the February mystery photo. For the benefit of new readers of the magazine, know that At A Glance mystery photos are traditionally poor photos of common species, good photos of uncommon species, or ambiguous photos of any species ever previously recorded in Massachusetts. The purpose of the column is to encourage readers to test their bird identification skills by looking at less than optimum views of birds without the benefit of clues usually provided in the field.
To kick off the new year’s challenge, notice by the slim proportions of the mystery bird’s legs, and what looks like could be the top of a fencepost, it is clearly a small bird of some type. It is also pale-breasted and devoid of streaks or other markings on its breast. Similarly, while we can’t see the side of the bird’s head, there is nothing to suggest that it has a prominent eyebrow stripe or distinctive crown markings on its head. Because the reader is looking at the back of the bird’s head, it is also obvious that the neck and nape areas of the bird are also uniformly colored. As with all of the mystery photos, readers are encouraged to also view the magazine image in color on the website at https://www.birdobserver.org/Issues/2021/February-2021/at-a-glance-february-2021.
A look at the image in color clearly shows that the undertail coverts are distinctly barred with black, and that the tail itself is also horizontally barred with thin dark lines. From the color view provided of the mystery species, these markings offer a definitive clue to the bird’s identity. Virtually no other small brown birds occurring in Massachusetts exhibit such prominently barred undertail coverts, or have the horizontal tail barring shown by the bird in the photograph. One or both of these features are, however, diagnostic of wrens and are not shared by any other North American passerines.
Once the mystery bird has been determined to be a wren, the identification is straightforward. The pale, unmarked breast, absence of flank barring, and no hint of a bold stripe over the eye collectively mark the identification as a House Wren (Troglodytes aedon).
The House Wren is a common and widespread summer resident in Massachusetts. It typically arrives in mid-April and departs by late October, although occasionally a lingering individual will appear on a Massachusetts Christmas Bird Count. House Wrens commonly occupy suburban birdboxes for nesting, but also readily nest in natural cavities in brushy areas or along woodland edges.
David Clapp captured this cryptic image of a House Wren in the Brewster Community Gardens in Brewster, Barnstable County, September 22, 2020.