On average, while not necessarily longer, female ospreys are 20% heavier than males and have a wingspan that is 5 to 10% greater. In North America, for example, male ospreys range in mass from 1200 to 1600 g, whereas females range from 1600 to 2000 g. Female ospreys also often have darker plumage and a more defined necklace than their male counterparts. Juvenile ospreys resemble adults, but have a somewhat speckled appearance due to buff-colored tips on their dark brown upper-wing and back coverts and a less well-defined necklace.