Red-necked grebes, Germany
© Edo van Uchelen/Minden Picture
The red-necked grebe is only red for about half the year. Its feathers are brown and grey throughout the winter, when it lives a low-key, quiet life in saltwater along North American and European coasts. But just before it migrates to a northerly lake, pond or swamp for breeding season, the plumage around the grebe's throat turns a distinctive red. Both males and females undergo the plumage change.
This colourful phase lasts from May to November, during which the previously calm bird becomes loud and performs rambunctious mating displays. Maybe it's all in the family: Grebes are more closely related to flamboyant flamingos than to their fellow diving seabirds.