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East Coast Sighting of Rare Bird Highlights Research by WIU Professor

February 15, 2019

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MACOMB/MOLINE, IL – Sightings of a rare colored Northern Cardinal continue to bring the research of a Western Illinois University biological sciences professor to the national stage.

Professor Brian D. Peer co-authored a paper in 2014 with Robert Motz, a retired Rock Island High School biology teacher. The research centered on a bilateral gynandromorph bird, which presents as a half male and half female cardinal. The bird has the brownish-gray feathers of a female on one side, and the red feathers of a male on its other side.

A couple in Erie, PA, recently saw what they believe to be one of the rare birds in their backyard. The bird frequents a dawn redwood tree near the couple's home and is typically in the company of a red male cardinal.

The sighting has generated new interest in Peer's research, which he and Motz conducted in the backyard of a Rock Island home, adjacent to the Black Hawk Forest Nature Preserve. The initial sighting by Motz and friend Jim Frink, while they were having coffee at the home, led to multiple observation periods between December 2008 and March 2010, and to the research paper.

"Sightings of these birds are exceedingly rare," said Peer. "Our research stands out because we were able to observe one of these birds more than 40 times over a two-year period. It amazes me that there is still this much interest in the cardinal."

Peer said when the birds are spotted, he frequently gets contacted because of his research.

"It would be great if this (Pennsylvania) couple could follow this bird into its breeding season," he said.

It's interesting, Peer said, that the most recent observations of bilateral gynandromorph birds have been cardinals.

"I never quite take cardinals for granted anymore," he said. "I always make sure to look at both sides of them in case there's another gynandromorph."

Peer and Motz's paper, "Observations of a Bilateral Gynandromorph Northern Cardinal (Cardinalis cardinalis)," was published in The Wilson Journal of Ornithology in December and was then featured in Science magazine. The full text of the paper can be found at

Peer's primary research focus is on cowbirds and the coevolutionary interaction between avian brood parasites and their hosts. He has also conducted research in the Quad Cities area on prothonotary warblers.

For more information about WIU's Department of Biological Sciences, visit

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