Rare documentation of a chimeric Black Redstart

Here is a peculiar story to lighten up the strange times we live in, with the novel Corona virus determining much of our days. We would also like to acknowledge that the Covid-19 pandemic affects Ornis Svecica, just like every other part of society, with editors, reviewers and others involved having more constraints on the time that they volunteer. For that reason, this story has been waiting for a while, ready to see the light of day. But this is prime season for singing Black Redstarts Phoenicurus ochrurus, so the timing is perhaps ideal.

About a year ago, Nicolas Martinez observed an unusual-looking Black Redstart in pair with a typical-looking male. Seen from one side, this peculiar bird looked like a male, and from the other side it predominantly looked like a female, with some male-looking parts mixed in. This rare phenomenon is known as bilateral gynandromorphism, and may produce animals that are half females and half males, with female and male organs in the different sides of their body!

While most of the observations of bilateral gynandromorphism in birds regards captive indidviduals, there are a few observations from the wild, including a Northern Cardinal featured in an article by National Geographic. The present contribution to Ornis Svecica (https://doi.org/10.34080/os.v30.20412) is one of few observations of a gynandromorph bird forming a stable pair bond, in which both birds sang, and provides unique documentation of the plumage before and after complete moult.

Enjoy the description, the photos, the song recordings, and the videos featuring this marvel of nature!