CHIFF CHAFF (Phylloscopus collybita)
The majority of the Chiff Chaffs in Switzerland are summer breeding visitors, but each year a small number are recorded in winter, usually around lake margins. Their range extends up to the tree line but they are at their densest in lowland areas especially in the north. The English name comes from the song which is supposed to be an up and down sing-song "chiff-chaff", but whilst it is not as simple as that, the song is nonetheless very distinctive:
You can hear that it is not just a simple up and down two-note song, but sometimes notes are sung at the same pitch and sometimes the pitch is reversed - in fact rarely does a bird do exactly what the field guide tells you it should ! It is really more a series of "chiffs". This can be seen more easily in the sonogram:
The individual notes are quite complex when you study the sonogram, each note starts with an almost vertical slide down from about 7 Khz to the main note at about 4 Khz, this may give it the piercing quality that makes it carry so far. But several notes in the sonogram also have a little tail after the main note - our human ears of course cannot detect any of this detail !
If you were listening carefully to the sound you may have heard the occasional little call that sounded like a soft "purruk", here is another sequence with several that can be heard clearly:
It is actually a double note as can be seen in this sonogram:
What this call is about I am not sure, bit it is often heard if you listen carefully and some birds even seem to use it to kick start the main song like this - listen for it just before the main "chiff chaff" phrase:
Another call that is made is a high-pitched "hweeet" that also carries a long way, some authors describe this as both a contact and an alarm call:
It is a short but continuously rising note:
Elsewhere I describe the confusion that exists between the songs of the Garden Warbler and Blackcap - two birds which sound the same but look very different. The Chiff Chaff is one of another pair that are actually quite the reverse - it and the Willow Warbler look very similar but sound completely different. In the field an adult Chiff Chaff has black legs and faint pale stripe through the eye, but the calls and song, usually coming from up in the canopy make this bird unmistakable. To learn the difference between the two look at Willow Warbler.
Song is of course used to attract a mate and defend a territory. One April I came across two males singing to each other when suddenly all hell broke loose and they came bursting out of the trees attacking and singing aggressively at each other, even singing during the chase - a great demonstration of just what song does mean to a bird:
These are tiny birds that weigh less than 20g, singing and chasing use up energy and also require time out from feeding, so these territorial actions clearly must be worth the risks they bring to the bird. This is one of the reasons why it is considered bad practise to play back recordings of bird song during the breeding season in order to attract them to a better view as it can be severely disruptive to normal behaviour.