“Ugly” and “attractive” are subjective characteristics assigned by HUMANS. They have nothing whatsoever to do with physiology.
I call BS on this and want to know what the author looks like. Sounds like he is using his grant dollars to troll for chicks.
That is undoubtedly wrong. There are all manner of studies showing the correlation between mating success and "beauty marks" such as plumage or colors, across numerous species.