I've never heard Onychognathus morio called Chestnut-winged Starling, only Red-winged Starling. Is this because i'm a young whippersnapper that doesn't know the proper old names for animals, or is it just a less-frequently used common name?
Chestnut-winged starling in my old Field Guide to the Birds of West Africa (Serle, Morel & Hartwig), which happened to be the book I checked to ascertain the sex of this bird. I grant you that other books and the NEZS Annual Reports use red-winged starling. But is that wing really red?
I was sure Red-winged and Chestnut-winged referred to different species, and having checked with Handbook of the Birds of the World Alive | HBW Alive, it seems that Chestnut-winged is Onychognathus fulgidus whilst Red-winged is Onychognathus morio.