We are excited to start welcoming our waders back to our coast but don’t worry if some of them look a little different to when they left our shores earlier this year.  Many of the birds returning through late summer will be in their breeding plumage.  Just when you think you’ve got identification sorted the birds throw in breeding plumage to confuse us all!

Fear not, we at Bird Wise are always learning so this article compares summer and winter plumage of a few of the waders you might see around north Kent and explores the reasons for their changing appearance.

Why do birds need to change plumage?

Firstly, let’s look at the plumage in general.  Feathers help birds survive by providing insulation as well as colour, camouflage, and patterns and perhaps most importantly their structure allows them to fly.  To keep their feathers in tip-top condition, birds will regularly preen and bathe in water or dust.  Despite this grooming, feathers become worn over time so at least once a year birds undergo a process of moulting.  Each worn feather is pushed out when a new one grows through the skin.  You might notice gaps where larger feathers have been lost and during moult birds can look scruffy, but this doesn’t last too long.

Birds can be more vulnerable during moult and some species will fly somewhere safer to undergo their moult.  Shelducks are an example of this as most of the UK population migrate across the North Sea to the Helgoland Bight, off the coast of Germany as during their moult they are completely flightless so need to be away from predators.  They return to our coast looking smart in their new feathers.

Why breeding plumage?

In the bird world, breeding season is a competitive place and for many species, the brighter and more striking the plumage, the more appealing to the opposite sex.  Breeding plumage is a way of showing off just how attractive they are to a potential mate or to intimidate rival birds.  Birds such as the Black Tailed Godwit turn a beautiful rusty red colour and Dunlin sport a black belly.  Summer plumage may also help with camouflage as birds migrate to different habitats for their breeding season where vegetation and flowers are growing again.  You might hear or read the term ‘sum plum’ which birders use to refer to a bird in its summer plumage.

When the breeding season is over and the winter months are approaching, there is no need to impress the opposite sex so the focus turns to survival, and this means camouflage.  With waders spending winter on mudflats and marshes, they need to blend into our muddy environment where bright colours would make them stand out, so they revert to duller winter plumage.

This also explains why many juvenile birds have different plumage to adults.  They don’t need to impress potential mates; they just need to stay hidden from predators.

Here’s a few examples of birds in their summer and winter plumage.

Dunlin – has a more brown speckled back and a black patch on the belly during summer returning to grey and white in winter

Turnstone – look for mottled brown patches on the back and wings with a white collar and white markings on the head during summer.

Black Tailed Godwit – a beautiful rusty brown during breeding season returning to grey in winter

Grey Plover – almost unrecognisable in summer and also known as the ‘black bellied plover’ in some countries.

Golden Plover – similar summer colouring to the grey plover but with the golden colouring on the back and wings

But it’s not only the waders that do this.  Some of the ducks do too.  Here is a Wigeon as an example, although we think they look brighter and much smarter in their winter plumage.

Wigeon

Not all birds change their plumage, in fact there are lots that stay the same year-round, which makes life much easier for us when we are doing our best to identify them.  Thank goodness for Oystercatchers and Avocets!

Don’t worry if you’re not sure what you are looking at.  With cameras on our phones and the online world at our fingertips it doesn’t take long to check, and if you are still not sure you can always drop us a post on our social media feeds.  This is where our online community is wonderful, if we don’t know there will always be somebody who does.

If you would like to learn more about what waders undergo during moult this Wader Tales blog explores how Golden Plovers cope with moulting.  For more general information on plumage, this article from The Spruce goes into the terminology of plumage.