WREN (Troglodytes troglodytes) - Troglodyte mignon
Summary
A very common species found in a wide variety of habitats right up to the mountain tops. It has an energetic song for such a small bird full of clicks, trills and warbles:
© Arlette Berlie
The Wren is one of the most widespread species in Switzerland, usually breeding where there is dense undergrowth it is most common at about 600m, but it can be found as high as 2,600m, usually in montane scrub at that altitude or perhaps around rocks and stone walls. This is a tiny but very energetic bird, I think of this as a bird with "attitude". For its size it makes a tremendous noise when it sings - cocking its tail up, throwing its head back, it puts its all and everything into a song which is a valiant, high-pitched, rapid trill:
It is hard to follow by ear so have a look at the sonogram:
© Arlette Berlie
It is a series of repeated rapid trills of different patterns lasting about 5 seconds. People have reported local dialects in wrens and the trills can be variable in pattern, this is especially so for the sub-species found on various islands. One common element in them all seems to be the rapid clicking followed by a trill that are the last two phrases of the above.
I agree it is hard to distinguish it all - so here it is again at one-third normal speed - since it is slowed down the pitch (frequency) is also lowered so it sounds weird, but it is easier to understand the pattern this way:
Wren one-third normal speed
Given that birds have a much finer and more accurate perception of time than humans, they can discern small changes very quickly. So the slowed down song above may be more akin to how another Wren would perceive the song.
Detail from a dead wren © Frank Jarvis
The above is the primary advertising / territorial song, usually given from an exposed perch, and it can be heard in virtually any month of the year, much less in winter of course. But Wrens also use a variety of clicks and “tuk” sounds to maintain contact between the pair, or parents and young, in the dense vegetation that they usually prefer. These will expand into strident alarm calls if a threat is perceived, usually given as single notes but becoming more rapid as the state of excitement rises.
It is a series of single notes, delivered in a fairly ad-hoc manner, and in common with many alarm calls it is extended over a broad range of frequencies, making it hard to locate in a precise way:
If the threat continues or increases, these single notes may be strung together into a series of rapid trills, in what has been called by some authors a “reeling” alarm call. It is usually given if an owl or a ground predator such as a cat, or weasel or a person is around (Cramp etal), and indicates a higher level of excitement:
Wren “reeling” alarm call
The classic study of Wren biology and behaviour was made by the Rev. E.A. Armstrong and published in the Collins New Naturalist Series in 1955, he apparently gives much more detail around the many variations in Wren vocalisations, but this is now a rare book, long out of print, and I have not been able to view a copy.
Wren studies © Frank Jarvis
