More gold...

More gold...with the common Goldeneye (not in HK, only USA and UK)

The male goldeneye’s metallic green head and bold white cheek patch aren’t just decorative — they’re the result of strong sexual selection. The shimmering green colour is structural iridescence, caused by microscopic feather structures that bend and reflect light.

• In bright sun it flashes emerald green. whereas In flat light it can look almost black.

That dramatic shift enhances visibility during courtship displays on dark winter water.

During courtship, males perform a striking head-throw display.

Unlike most ducks, goldeneyes are cavity nesters.They use old woodpecker holes and can nest several metres up in trees, sometimes far from water.

Even more amazing — the fluffy ducklings leap from the nest hole when just a day old and bounce safely to the ground before heading to water with their mother.

Goldeneyes are nicknamed “Whistlers.”When they fly, their stiff wing feathers produce a distinctive clear whistling sound — loud enough to identify the species overhead even before you see the white wing patch. On a cold winter lake in the UK, that sound is often the first clue they’ve arrived.

Females have a rich brown head, unlike the glossy green-black of adult males.

You can see the distinct white patch at the base of the neck separating the brown head from the grey body — a strong female goldeneye feature.