WILLOW TIT (Poecile montanus) - Mésange boréale
Summary
Common in all woodlands but especially in pine forests up to the treeline at 2500m. There are two subspecies in Switzerland that have different songs, so voice is key in identifying this species:
The Willow Tit is very difficult to tell visually from the Marsh Tit it has a dull black cap as opposed to glossy, and in summer has a small pale patch in the wing but both of these are really difficult to see (see diary notes from Frank Jarvis at the bottom of this page). As its name suggests it is commoner at higher elevations than the Marsh Tit, but both can be found together anywhere between 500m-1500m, but the Willow Tit will extend upwards to 2500m. It is therefore fortuitous for bird watchers that their calls and songs are completely different (so compare with the Marsh Tit page).
The most distinctive sound is the nasally scolding call that is not only used for alarm but is also used for contact purposes:
Like such calls we can find elsewhere it contains a wide range of frequencies (a sort of Willow Tit broadband !) and can be difficult to locate as a consequence:
The song is a series of repeated, rather plaintive downwards inflected whistles - "tsui, tsui, tsui"
The shape of the sonogram being quite distinctive:
It is possible to confuse the song of the Willow Tit with the "pluie" song of the Wood Warbler . To my ears the Willow Tit is slower and more deliberate, the Wood Warbler slightly faster and for reasons I cannot explain sounds a bit more plaintive. Here is a mixed file of song sequences: two Willow Tit, three Wood Warbler, then two Willow Tit again:
If you review the sonogram of this same file you can see that the Wood Warbler (middle three) descends much faster and is delivered more rapidly than the Willow Tit (first and last two):
(NB: the timing between phrases (but not the notes) was shortened in those to make the files smaller)
SUB-SPECIES DIFFERENCES IN SWITZERLAND: The above recordings were made in the Jura, north of Lac Léman (Lake Geneva), which is about the southern limit of the central European sub-species Poecile montanus salicarius. In the Alps and to the south and east of Lac Léman is found what we call the nominate sub-species (i.e. the one to which the original name was given before other sub-species were discovered) this is Poecile montanus montanus which is referred to by some authors as Alpine Tit, it has a different song where the individual notes do not descend but are of fairly constant pitch - here is a recording I made in the Lower Engadine:
This is much faster, not as deliberate, and even though each run descends slightly in pitch the single notes are fairly even. It becomes clearer if you hear them side by side (salicarius first):
and very clear from the spectrogram:
Willow Tit (P.m.salicarius) (2 songs) followed by Alpine Tit (P.m.montanus) (3 songs)
Maumary, Valloton, and Knause (2007) also note that in Switzerland a third sub-species P.m.rhenanus can be found in the lowlands of the plateau, but subtle plumage differences rather than voice seem to be the only way to identify this one. For more on all of this also see Cramp et al (1977-1994) and a detailed discussion in the latest Atlas of Breeding birds of Switzerland Knaus et al 2018.
Willow Tit and Marsh Tit compared © Frank Jarvis
