Grey Or Yellow?

A couple of days of wet and windy weather have restricted my birding for a while. So for today I hope to answer the question “When is a grey wagtail not a Grey Wagtail but a Yellow Wagtail”?

It’s a subject that cropped up on my last post at Another Bird Blog when a reader suggested via a comment that my image of a Yellow Wagtail was in fact a Grey Wagtail.  The photograph is the one below. 

Yellow Wagtail

The species under discussion are two closely related ones, Yellow Wagtail Motacilla flava and Grey Wagtail Motacilla cinerea. 

The images below are pages from the The Crossley Guide that show not only the plumage differences between the two wagtails but also the different habitats and situations in which each is usually found. I’m sure that at most times of the year almost everyone can identify the adults of both species as they are really quite different in appearance.

Grey Wagtail - Richard Crossley (The Crossley ID Guide Britain and Ireland) [CC BY-SA 3.0 a/3.0)] via Wikimedia Commons 

 Yellow Wagtail Yellow Wagtail - Richard Crossley (The Crossley ID Guide Britain and Ireland) [CC BY-SA 3.0 via Wikimedia Commons

The Yellow Wagtail, male or female, is an overall shade of yellow, whereas the Grey Wagtail while having parts of striking yellow plumage in both male and female, is an overall grey colour above.  No problem there then. 

 Yellow Wagtail

Grey Wagtail

Less practiced bird watchers may experience confusion and misperception when dealing with autumnal “grey” Yellow Wagtails such as the one in my picture at the top of this post, a very pale and quite fresh Yellow Wagtail in its first autumn plumage during September. At this time of year juvenile Yellow Wagtails are greyish/brown/olive above and buff whitish below, with a partly yellow belly and yellow under tail. Rather than the bright yellow and immaculate males of some field guides, autumn encounters of both species usually involve less bright and slightly worn plumaged adults of either sex, or duller juveniles. 

My pictures below show the typical dark, almost black legs of a Yellow Wagtail and not the flesh coloured legs of a Grey Wagtail. The Yellow Wagtail has clearly defined wing bars as formed by the pale covert feathers. By comparison a Grey Wagtail of any age always displays slate grey wing feathers together with narrowly edged greyish coverts rather than the much whiter ones in the wing of a Yellow Wagtail.

Grey Wagtail

Yellow Wagtail

 

Grey Wagtail

Yellow Wagtail

Grey Wagtail

Yellow Wagtail

Yellow Wagtail

A feature that is less obvious unless the two species are side by side is that the Grey Wagtail has a very long white edged tail whereas a Yellow Wagtail has a shorter tail. This is a useful separation tool in the field when the long tail of a Grey Wagtail “bobs” and “pumps” almost incessantly as opposed to the less mobile and much shorter tail of the Yellow Wagtail. A Yellow Wagtail has a demeanour rather like a pipit, often standing taller than the similarly sized Grey Wagtail that can appear quite "crouching". 

Another separation in the field is the differing calls of the two species. The Yellow Wagtail has a sweet “tsee” or “schlee” or a louder “suree”. The call of Grey Wagtail is totally different with an explosive, metallic “zi-zi” or “tsvit”

Below is a great video from the BTO which not only sets out the difference between Yellow and Grey Wagtails, but for good measure also includes the Pied Wagtail Motacilla alba, yet another “grey” wagtail.

I hope this post has been helpful to anyone unsure about separating Yellow Wagtails and Grey Wagtails, or even grey wagtails.

And for anyone looking for a top quality field guide to the birds of Great Britain and Ireland I recommend the following three books:

• The Crossley ID Guide: Britain and Ireland   
• Britain's Birds  
• The Collins Guide 

That's all for now. Back soon with Another Bird Blog. In the meantime I'm linking this post to Stewart's World Bird Wednesday