Through the dark, cold days of winter our natural world slumbered deeply on. In February and March, life moved into an early seasonal doze but with April almost here, and May just around the corner, it is now fully awake in all its riotous colour and sound.

In the world of birds, nearly all our migrants have arrived back from their travels to the sun and are ultra keen to start domestic duties once more.

This is the time when the male avian world shouts ‘here I am’ and, once that side is sorted out, things move on to ‘this is my territory’ and ‘it’s a great day to be alive’.

In simplistic terms, these are just a few of the reasons that birds sing and if you add in ‘I’m over here’ contact calls, you can easily see why the dawn chorus is such a feathered Last Night of the Proms.

But, for the birder in the field, these songs and calls are one of the best ways to find and see some of our more retiring species, quite often the only way to realise that they are within spotting range.

Lesser whitethroat, blackcap, firecrest and grasshopper warbler are often almost impossible at times to get a glimpse of and that increasing rarity — turtle dove — is often discovered first by its constant purring from within deep hedgerows.

Even the more common bullfinch, the tit families and those seemingly dull, little brown jobs, the warblers, are all distinctive singers worth recognising.

Geoff Sample is a sound recordist who has published several books with CDs of bird songs and calls and I heartily recommend them as essential aids to to get the best from your spring field trips.

Otmoor, with its footpaths, thick hedges and a superb range of species is the classic site to practise and it becomes much easier when you have learnt what made that call. So, with iPod or CD player get familiar with the language of our birds and seek out those skulkers.

Keith Clack Oxford Ornithological Society