Gender Determination in Ospreys
It is possible to determine the gender of an osprey by observing the coloration of their chest.
A female osprey has a band of dark brownish streaks on her throat and around the neck and upper chest, sometimes referred to as a necklace.
A male osprey has a white chest, uniformly pale underwing feathers, and a weaker or non-existent breast band.
Note: Many chicks start out with a necklace and then lose them as they mature. Therefore, necklaces in young ospreys are not reliable indicators of gender.
Female left - Male right
Other Indicators of gender in adult osprey:
Adult female ospreys are always bigger than male ospreys (as much as 1/3 bigger).
Adult male ospreys have narrower wigs than females.
Male
Male
Female
Female