This book appeared in spring 2013. It is written in Dutch for a broad audience and is a volume in the series Wetenschappelijke Bibliotheek (Scientific Library) published by Veen Media. It is built upon field studies on the behaviour of ruffs and gulls in the Dutch provinces Groningen, Friesland en Drenthe between 1964 and 1986. These studies are connected with current scientific theory. A complete list of references is supplied here.
It is centered around the question why a cock differs from a hen, a buck from an ewe, a man from a woman. Usually, male animals that are bossy or sexy get more mates and thus more offspring. This is different in female animals. If they would be bossy or sexy, their infants suffer. In many animal species variation among females in offspring numbers is small. Among the males only a few sire many more offspring than reared by an average female, but most sire less or no offspring at all. Males differ from females by sexual selection.
This was the most brilliant and most original idea by Charles Darwin. That idea runs through the book like a thread: a life-long search for partner choice and care in ruffs, gulls, ratite birds, monkeys, apes, also humans including Charles Darwin.
Painting by Eugen de Blaas: 'the flirtation' (1904).