BIRD GUIDING AROUND OSLO

Thursday, 29 November 2018

Marsh vs. Willow Tit


Marsh (løvmeis) and Willow Tits (granmeis) are notoriously difficult to separate on plumage especially in the UK where the kleischmidti subspecies of Willow Tit is a much warmer coloured bird than the borealis that we have in southern Scandinavia. I have always relied on call to identify Marsh and Willow Tits and luckily both species (like most tits) do call frequently. Even calls though need to be listened well to as Marsh Tit has some calls that are similar to Willow and Great Tit can do a very good Marsh Tit impersonation (I would never report a Marsh Tit just on call if it was from a new locality).

Plumage wise there are some very warm coloured Marsh Tits that are easy to ID without call and some pale Willows that are equally striking. There are however a lot of birds that are far less obvious, and I am rather in awe of those people who confidently identify these birds based on poor photos (although I suspect many of them do not appreciate the subtleties and variation in plumage that exists). The one time that I have entered into an ID debate was when a very good photo was posted in Facebook. After a while when nobody had commented then I gave my opinion (backed up with reasons) only to find that other people strongly believed (and with good reasons) that I was wrong.

When I found a Marsh Tit in Maridalen on Monday I found it due to it calling and then saw it (thus eliminating a Great Tit). Upon seeing it however I was struck by how striking the pale wing panel was on this bird (a feature normally used to ID Willow Tit) and how white the cheeks were. The black bid could also change in appearance depending on pose. The brown areas of the bird though were warm in colour and I saw this as a good ID character plus I also noted the pale spot on the base of the upper mandible (but only in my pictures) which is supposed to be THE diagnostic character for Marsh Tits although I have previously noted what very much looks like the same spot on Willow Tits….

What then made things harder was when I saw Willow Tits close by (confirmed by call) and they looked equally warm brown and to be honest I couldn’t find any clear plumage differences.

These pictures try to compare the birds and I have commented the key features as I see it.


The WHITISH WING PANEL is supposed to be the main ID feature to separate Marsh (bottom) and Willow Tit (top) but in this picture we can see that both species can show this feature even though it is supposed to be absent on Marsh. Note also that both have warm coloured flanks. One distinguishing feature is visible on this picture though and that is that the rear cheeks of the Marsh are slightly brown fringed and are separated from the white forecheeks by a dark line whereas the Willow has just white cheeks

Here the Marsh (top) is a bit over-exposed and the cheeks look much whiter. An old feature was that Marsh should have a glossy cap and Willow a matter cap although this feature is now known to be of a little use and I would say these pictures show the complete opposite 
This picture shows the cheeks a bit better and the browner rear cheeks and dividing line are just about visible on the Marsh (right). Marsh Tit is also supposed to show a pale spot at the base of the upper mandible (beak) which is visible here but the Willow (left) also shows this..

Another feature that is mentioned is that Willow (left) has a large black bib with a messier lower border and this picture definitely shows that, but.....

...look how the bib of Marsh Tit can change depending on angle and posture!

MARSH TIT (same bird in all photos):
Here the Marsh Tit does not look to have a particularly pale wing panel

Marsh Tit

Marsh Tit with the wing panel looking quite pale but note rear cheeks

Marsh Tit - here the separating line on the cheek is clearly seen
 
Marsh Tit - here the pale spot at the base of the upper mandible can be seen and the markedly pale cutting edges to both upper and lower mandible are also supposedly a good pro Marsh character

here the bib of the Marsh Tit looks large
 WILLOW TIT (note different birds are photographed):
Willow Tit (granmeis) with a not particularly striking wing panel

Willow Tit - note that Willow Tit also seems to have a larger head than Marsh 

in this angle the wing panel of this Willow Tit is very obvious and a Marsh Tit would never look quite like this

Willow Tit - very white cheeks and thick white edges to the tertials

Willow Tit - does the rear cheek look slightly less white?

at this angle the Willow Tit does look to have small neat black bib and could definitely invite thoughts of it being a Marsh. The pale cutting edges to the bill are probably less obvious than on Marsh Tit

the flanks of this Willow Tit are also warm coloured 
Willow Tit




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