HAWFINCH (Coccothraustes coccothraustes)
The Hawfinch is not such a large bird, but it has a huge beak connected to powerful muscles which give it a large headed, bull-necked appearance - a real strongman of the bird world. The bill is a bright blue colour, and along with the size of the head, palish forehead and dark line through the eye, it has a rather startling appearance - a sort of super-sparrow on steroids. Maybe I am just impressed by it because I know that with that apparatus it has the ability, and indulges regularly, in cracking cherry stones - anyone who has broken a tooth on a cherry stone knows what that entails !
But despite this drama it is actually a rather shy and secretive bird which is hard to see. I am more aware of them in winter when the trees are bare, but when also numbers may be supplemented by birds from further north. In winter it also visits my bird feeder where it seems to like the sunflower seeds in the mix I use. Although the books tell me that there is a song of some rhythmic quality I have never heard it never mind recorded it. I do however regularly hear its very high-pitched short "tsisp" call which is often given from an exposed perch:
In that recording you could also hear a Mistle Thrush sounding out its annoyance and in the closing seconds a Crossbill flew in making its chattering call, but the Hawfinch is unmistakable in the high frequency it uses. In the sonogram the call shows up like an inverted "V" shape rising from 7Khz up to 9.3Khz then back down to about 6.2 Khz, but since all this happens in about 0.2 secs our hearing cannot discern this degree of detail:
So here is the fascinating thing: we do not really know how other birds hear these calls - it is very likely that another Hawfinch can in fact pick out that clear up and down slide in what to us is a very brief explosion of sound. If we slow it down to one-tenth of the normal speed the task for human ears becomes much easier and is probably something akin to what other birds can discern:
At that slow speed you can also hear another bird responding in the distance.
If we analyse things this way we can begin to get some sense of the amount of information that could be hidden within calls and songs of which we are completely unaware. Food for thought there.......