Female Great Spotted Woodpecker N.E.London (1 Viewer)

Initially I assumed the bird must have trailed it's tail through some lichen at some time, however on closer inspection not so sure?

Cheers

Staining from debris at the base of the nest cavity or tree sap / water seepage on a trunk as it uses it's tail for 'support'?

foresttwitcher said:

Staining from debris at the base of the nest cavity or tree sap / water seepage on a trunk as it uses it's tail for 'support'?

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Most likely.:t:

foresttwitcher said:

Staining from debris at the base of the nest cavity or tree sap / water seepage on a trunk as it uses it's tail for 'support'?

Click to expand...

During the interim I’ve endeavoured to image three other “different” GSW’s another female a male and a “redhead” and they all appear to have a consistent yellow wash to the two white tail end feathers only!

I then found another single “feeder” shot (taken several years ago) which also had the same yellow wash to the underside of the end tail feathers.

This got me looking on the web where I found just a single image showing the same end of tail feathers, as all other images are invariably profiled shots only.
The last two “white” rectrices are not visible on virtually all GSW shots because the birds are rarely in that acute angled position enabling this possible “feature” to be seen particularly in the field.

I’d be interested to know if this apparently consistent “yellow wash” to the under tail (only), has been observed and noted before, although of no use for ID purposes and assuming it’s a regular tint to the aforesaid, am wondering if it could be manifest on any other Dendrocopus species....or am I barking up the wrong sap run?

PS I don’t think this yellow wash would be observable in the field under normal viewing conditions. Would be interesting if any ringers have handled GSW and have observed this feature before, believing that it is the result of a sap run, as I’m finding it somewhat co-incidental that the different five imaged birds should all have the same symmetrical yellow tint to just the same two feathers.

Cheers

But in your original photo the yellow staining is not just on the two feathers but also, albeit to a lesser extent, on the edges of the next two shorter feathers. Perhaps reflecting the depth to which the tail has been dipped into the liquid at the base of the nest cavity.

foresttwitcher said:

But in your original photo the yellow staining is not just on the two feathers but also, albeit to a lesser extent, on the edges of the next two shorter feathers. Perhaps reflecting the depth to which the tail has been dipped into the liquid at the base of the nest cavity.

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Subsequent to my last post today, I observed a different (more dusky) female also sporting the yellow wash to the last two under-tail feathers that’s now six individuals at different times and different places showing the same feature.

Interestingly on some of the individuals, there are individual white fronds within the black terminal tail feathers below the lowest row of “white” rectrices that show no yellow staining.

Yes, there is a smidgin of yellow tint to the corners of the adjacent (upper) row of white feathers...but only on the one image so far.

I believe six examples so far...warrants further investigation?

Cheers

All visiting one particular feeder somewhere which has yellow stuff on the underside?

What makes you think this isn’t normal feather colouring? GSW typically have ‘nicotine’ tinges to white feather areas (eg on the forehead, the breast and tips of the outer tail feathers).

https://www.featherbase.info/en/species/Dendrocopos/major

https://www.pikist.com/free-photo-ipbar

Perhaps it’s not so readily noticeable because the views most people have are of birds clinging to trees with side or dorsal views only.

Deb Burhinus said:

What makes you think this isn’t normal feather colouring? GSW typically have ‘nicotine’ tinges to white feather areas (eg on the forehead, the breast and tips of the outer tail feathers).

https://www.featherbase.info/en/species/Dendrocopos/major

https://www.pikist.com/free-photo-ipbar

Perhaps it’s not so readily noticeable because the views most people have are of birds clinging to trees with side or dorsal views only.

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Thank you Deb you've proved my point, with the images numbered 4568/5179 and the second link with GSW on the branch viewed from beneath, all clearly showing the yellow tint/wash to the last ''white'' feathers above the black tail tips...I believe mission accomplished. :t:

KenM said:

Thank you Deb you've proved my point, with the images numbered 4568/5179 and the second link with GSW on the branch viewed from beneath, all clearly showing the yellow tint/wash to the last ''white'' feathers above the black tail tips...I believe mission accomplished. :t:

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I used to take copious fieldnotes in my early days (including of GSW) back in the day where observations and ID weren’t assisted by HD digital imaging. It certainly helped to commit the ‘finer’ details of plumage to memory - I even used a yellow crayon on one of the sketches of a GSW.

Deb Burhinus said:

I used to take copious fieldnotes in my early days (including of GSW) back in the day where observations and ID weren’t assisted by HD digital imaging. It certainly helped to commit the ‘finer’ details of plumage to memory - I even used a yellow crayon on one of the sketches of a GSW.

Click to expand...

Yes Deb, yellow is not a colour one would associate with GSW, however a colleague sent me a superb image of the aforesaid with bright yellow UTC’s!!

Cheers