Sunday, February 3, 2019

Bewick's Wren in Dearborn: historical report

NOTE: In anticipation of publishing a new Dearborn bird checklist, I am posting information on some of the city's more interesting sightings. 


In my post about Michigan's second record of Bachman's Sparrow (Peucaea aestivalis), I introduced Alice Miller, a Dearborn bird bander and active contributor and compiler of bird surveys in the Detroit region into the early 1950s. Here is yet another of her interesting Dearborn sightings.

On her survey forms in 1948 she made a convincing although cautious report of a Bewick's Wren (Thryomanes bewickii) in her yard on 11 April 1948.

Survey forms including Bewick's Wren submitted by Alice Miller.
The penciled description on the back of thin paper are hard to read, so here is a transcription:
Bewick's Wren - probable
1st observation 4-11 Naked eye - on bare ground directly under living room window - brown - slender - positive white eye stripe (over) - whitish underparts - long tail - out of range
2nd observation - in spirea bush - extemely quick nervous movements up down in and about - out of range
3rd ob. atop low stone wall back of lot - same as 1st plus definite and prominent side to side tail movement. But never saw white in tail to make it positive - I had just returned previous week from Tennessee whre I saw Carolina's for positive study - This was not a Carolina and it's back was plain and not striped so it couldn't have been a marsh wren
This report did not get published in the spring 1948 bird survey. However, although this form was dated for summer 1948 (see top portion of photo above), all the records on the pages were from spring 1948. She notes she had been travelling, so perhaps she missed the spring deadline. Normally, significant reports that were omitted were mentioned in the following survey when published, but the summer 1948 survey itself was not published on schedule, and appeared in condensed form along with the fall 1948 survey.

Whether a paperwork foul-up or a decision not to publish the record due to uncertainty we will never know. Nonetheless, Alice Miller was an experienced and careful observer, and her description rings true and seems adequate to me. It's validity is supported by the fact that Bewick's Wrens were much more common in the eastern U.S. decades ago, and rare but regular in Michigan during that era. In their 1959 publication, A Distributional Check-list of the Birds of Michigan, Zimmerman and Van Tyne considered Bewick's Wren a "rare and irregular summer resident" with "most records in April and May". Alice Kelley noted 22 records in the region between 1945 and 1974 in her book Birds of southeastern Michigan and southwestern Ontario, while The Birds of Washtenaw County lists at least 7 records there up to 1970. There have been very few since then.

Based on these facts, I consider this a valid record for Dearborn.

Read more about the status of Bewick's Wren in the eastern U.S.:
  • This paper by Michael Hodge and Gary Ritchison appeared in the state journal The Kentucky Warbler in November 2007: Bewick's Wren in Kentucky and Tennessee: distribution, breeding success, habitat use, and interactions with House Wrens. It gives an interesting summary on the history of this species in the eastern U.S.
  • So does this earlier paper from 1978 from the Carolina Bird Club journal, The Chat: Ecological factors contributing to the decline of. Bewick's Wren as a breeding species in the southern Blue Ridge (PDF).

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