What does it mean when a bird is in eclipse?

What does it mean when a bird is in eclipse?

Did you know the word eclipse means to cover, obscure or hide?

If you have been looking into birds recently you might have noticed the term “eclipse” or “eclipse plumage”. If you’re curious as to what this means, keep reading.

In a nutshell “eclipse plumage” is the colouration of a duck (or other water fowls) plumage after the breeding season has finished and their seasonal moult has occurred.

Why Do Ducks Moult?

All birds moult after the breeding season to replace any damaged or worn out feathers. This ensures the bird can safely fly and keep warm during the following winter period.

However, there are some differences in the way various birds moult. Many birds go through what is known as a sequential moult. 

This is where the bird loses one flight feather at a time running from the inner primary feather out to the wing tip. This allows the bird to still be able to fly during the moult.

Whereas ducks and many other waterfowl go through what is known as a simultaneous moult. This is where the duck loses all of its flight feathers in one go making it vulnerable to predators because it cannot fly away.


This inability to fly lasts for around 20 to 40 days depending on the species. During this time the once brightly coloured male bird takes on plumage that makes it almost impossible to distinguish it from the female of the species.

This drab colouration allows the flightless male duck to blend into its habitat making it harder for predators to detect its presence.

How To Tell Male & Female Mallards Apart During Eclipse Plumage

Mallard male

Taking the mallard as an example, the males are typically slightly larger. But what makes them stand out is their bright colouration. With their dark green heads, purple-brown breasts, purple-blue wing patches and grey bodies they are easy to distinguish from the female.

Female mallards have a mottled brown body and purple-blue wing patches.

However, during the eclipse plumage period, the males lose all of their colouration and take on the brown mottled appearance of the females. This can make sexing mallards at this time difficult.

In fact, many people mistakenly assume that the males have flown away during this time. There is however, a sure fire way to differentiate between the sexes of mallards when in eclipse.

All you need to do is look at the bird’s bill, if it’s a uniform yellow colour, that’s the male. The female has an orange bill with black markings. Other tell-tale signs include the brown feathers on the male are slightly darker than those of the female.

Plus if you look closely at the crown of their heads, you might just notice a slight green stripe just behind the eyes.

The Eclipse Of The Mallard 

The eclipse moult of the male mallard starts towards the end of June and runs through July and August which are the main 2 months when mallards are flightless.

By September, the males’ colours are usually back to their usual display making them easy to identify once again.

As you can see, for 3 seasons of the year, Autumn, Winter & Spring, the male mallard displays its bright colourful plumage. It’s just through the Summer season (after breeding) that it loses its colourful feathers and takes on a more drab appearance.

Which Other Waterfowl Has Eclipse Plumage?

There are many other waterfowl that take on an eclipse plumage including;

  • Mallards
  • Wood Ducks
  • Northern Pintails
  • Northern Shovelers
  • Blue-Winged Teal
  • Green-Winged Teal
  • Mandarin Ducks
  • Red-Crested Pochard
  • Red-Breasted Merganser
  • Red-Legged Partridges
  • And Many More

What It Means When A Bird Is In Eclipse (in simple terms)

When a bird is in eclipse, it means the bird, especially a male duck or similar waterfowl, has temporarily lost its bright and colourful feathers after the breeding season. This happens during a period of moulting, where the bird replaces old or damaged feathers. 

During eclipse, these birds take on a more dull, camouflaged plumage that helps them blend into their surroundings and stay safe from predators, especially since many can’t fly during this time. 

In simple terms, “eclipse” is like a bird’s way of going undercover with a more muted appearance for a short period each year.

Frequently Asked Questions

What is the difference between a drake and an eclipse drake?

The difference between a drake and an eclipse drake is the colouration of the bird’s feathers. Drakes (or male) ducks are typically brightly coloured in order to attract a female for breeding purposes. After the breeding season the drake moults and loses the ability to fly. It then takes on its eclipse plumage which is far more drab and able to blend into the habitat the duck lives in. This makes it less likely to be caught by any predators.

How can you tell if a Mallard is male or female during eclipse?

The easy way to differentiate between male and female mallards during the eclipse plumage phase is to look at their bills. A male will have a uniform yellow bill whilst the female’s bill is orange with black markings.

What does Eclipse Drake mean?

The term “eclipse drake” refers to the loss of the drake’s colourful plumage during the eclipse phase. During this period the drake moults its feathers and loses the ability to fly. It then takes on drab brown feathers to help it camouflage into its surroundings.