Casanovagen plot
The film begins as a search for the Casanova gene in songbirds, the so-called infidelity gene, which is being researched at the Max Planck Institute in Seewiesen. For male birds, infidelity is biologically and evolutionarily obvious, the scientists say. This way they can enlarge their offspring. But what is the 'use' for females, who turn out to inherit the gene through their father? Is it a genetic flaw, a superfluous trait? Or does every bird eventually sing as it is called? Director Donschen goes in search of what desire and intimacy mean in a world in which gender roles and views on sexuality are shifting.