A male European Nightjar, showing its prominent white wing and tail ornaments during a territorial display. Photo: Ervín Hrtan A study on how white patches convey the quality of male European Nightjars By Richard Schnürmacher Many avian species sport bright, contrasting colours, but what about the birds active at night? Variation in the white markings of adult male European Nightjars suggests sexual selection on their size. Age and body condition strongly influence how big