BLACK REDSTART (Phoenicurus ochruros)
Although most common in the lowlands, the Black Redstart is found everywhere in Switzerland - right up to the highest levels in the alps at the snowline. It is naturally a bird of scree slopes and boulder fields and so the mountains above the tree-line are ideal habitat. It feeds on small insects upon which it dives down from a high perch, or which it chases along the ground, it can also take small fruits. However this selection of open rocky areas also makes it ideally pre-adapted to man-made habitats. So buildings, farm yards, dry-stone walls etc all make ideal territories. In the Jura almost every mountain farm has a pair of Black Redstarts in residence, profiting from the abundant insects around the cow sheds. They are quite unafraid of human presence, a pair nested right above the front door a house I lived in for many years.
They like to sing from exposed perches and so are very obvious with an upright stance and a hurried rattling song which can carry quite a long distance. Each song phrase lasts 3-4 seconds and consists of three parts - it starts with a series of accelerating warbling notes followed by a short pause (about 0.5 secs only), this is then followed by a very peculiar rattling noise that some people say sounds like a small bag of metal ball bearings being shaken around, this runs continuously into the third and last part which is another series of warbling notes:
The three parts can be seen quite clearly in the following sonogram which is of two phrases with the time between them shortened for convenience:
The rattling sequence is a very strange activity, even if we slow it down to half speed and expand the scale the separate notes there cannot be distinguished it is so rapid, but the accelerating rate of the first warble is more obvious at that slower speed:
Whilst this is the most obvious evidence of its presence it also does a series of single note contact calls; here is a female with 3 young recently out of the nest, she was calling to keep contact with them but the note (a hard chat-like noise) also seems to have a touch of alarm to it, perhaps caused by my presence:
But when seriously threatened the alarm notes take on a much more rapid character - here is a male in August chasing a Stoat, or Ermine (Mustela erminea) through rocks and boulders on a hot summer day with lots of hover flies around: