Bird identification can often be a real challenge.  Birds captured at banding stations sometimes provide an opportunity to study unusual plumages.

In the spring of 2014, researchers at Long Point Bird Observatory captured an interesting-looking warbler which somewhat resembled a Magnolia Warbler.

After a detailed inspection of the bird’s plumage and a genetic analysis, it was determined that the bird is the first-ever documented hybrid between Magnolia and Chestnut-sided warblers.

Male Magnolia Warbler

Male Magnolia Warbler


Female Chestnut-sided Warbler.

Female Chestnut-sided Warbler.



Hybrid Magnolia x Chestnut-sided Warbler.

The results were published by Ken Burrell (Natural Resources Inc.), Jeff Skevington and Scott Kelso (Agriculture and Agri-food Canada), and Mike Burrell, Dayna LeClair, and Stu Mackenzie (Bird Studies Canada) in the most recent issue of the Wilson Journal of Ornithology.

Here is the abstract of the article.  Subscribers to the Wilson Journal can read the entire article

New World Warblers represent a complex and closely related family, with a high propensity to hybridize. With more than 73 known hybrid pairings of Parulidae documented, we report a previously undocumented hybrid: a Chestnut-sided (Setophaga pensylvanica) × Magnolia Warbler (S. magnolia). The parentage of the hybrid individual and its identity are supported by morphological and genetic evidence. DNA sequencing of a fragment of cytochrome oxidase c subunit I (COI) supports the female parent as Chestnut-sided, while strong morphological features support Magnolia Warbler as the father.

The new hybrid represents the first documented hybridization of Chestnut-sided Warbler.

Although hybrid warblers are rare, they do occur.  The most well-known are perhaps the Blue-winged x Golden-winged Warbler hybrids.

First generation hybrids are know as Brewster’s Warbler and have a Blue-winged head pattern.  The even rarer Lawrences’s Warbler is a Blue-winged x Golden-winged hybrid that has a Golden-winged head pattern.

Blue-winged Warlber.

Blue-winged Warbler.


Golden-winged Warbler

Golden-winged Warbler


Brewster's Warbler

Brewster’s Warbler

Hybird Chestnut-sided Warbler x Magnolia Warbler photograph by Ken Burrell.

Other warbler images © Greg Lavaty.

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