Of course, an obvious theme for my blogs at this time of year must surely be a ‘looking forward to spring’. But let’s just see, I’d hate just to be a written version of Springwatch. I did however, notice yesterday that the Chaffinch has just started making its bid for a place in the great dawn chorus come April/May time. Admittedly it’s not quite his full flourish of notes but rather more a sub-song.
Sub-songs are not uncommon and even the familiar Blackbird can be heard warbling out some practice notes from the depths of a bush in mid-winter. Like us, a bit of practice seems to be needed before going on stage or out on a limb, so to speak.
While birds always have a variety of calls in addition to their main ‘song’ – scolding and warning notes, flight calls and so on – I’ve always found it interesting that there are also calls linked specifically to a change in season. The most famous of these is perhaps the Cuckoo who even has a rhyme to its name in which, having sung all day in May, come June it ‘changes its tune’ or some would say ‘forgets its tune’.
Last year, at dusk on 13th March at a local reed-bed, I had one of those rare moments to witness another more unusual bird giving its own version of a seasonal call. Three Bitterns, usually perfectly camouflaged amongst the reeds and usually only seen as singles, flew high above the reed-bed heading off east. This was the start of their migration from their winter home to their breeding grounds and as they flew they gave a strange throaty, gull-like call – a migration call.
Previously, I’d only known Bitterns to ‘boom’ from the depths of the reed-bed – strange enough in itself and a sound that you only pick up if you tune your ears into it. But this new call, signalling the start of a seasonal journey was loud and clear and I felt somewhat privileged to witness the moment of departure.