Bird Identification using Song and Calls
I have nearly always found that songs, calls or other sounds made by birds such as the drumming of woodpeckers or Snipe are a great help to identification. They are often very distinctive. Indeed, it is easier to separate the Chiffchaff and Willow Warbler, Marsh and Willow Tit by their song rather than relying on a distant view.
On the other hand, the songs of at least two pairs of birds are difficult to separate, they are the Garden Warbler and the Blackcap, which often sing in similar woodland habitats, and also the Sedge and Reed Warblers, in marshes, and if you happen to be on the Continent or even in some parts of western England you may have the Marsh Warbler to add to the confusion.
However, with practice it is possible to sort out most of these problems. Each species has its own vocabulary of call notes by which it communicates to other members of its own species, and sometimes with individuals of similar but different species. The calls of closely related species can be very similar and need a lot of learning. The communication calls of feeding flocks of tits takes a bit of disentangling as do the ‘tacs’, ‘tecs’ and ‘tucs’ of the Garden Warblers, Blackcaps, Whitethroats, Lesser Whitethroats and a host of other warblers.
Like everything else, you learn the song by listening to a strange call in the field, then tracking down the unknown singer and identifying it visually. There is nothing like the frustration of hearing an invisible bird singing to imprint that song on your memory. A friend may open your ears to a song but should not tell you what it is until you have tried to identify it for yourself. I learnt bird song the hard way by tracking down the singer. However, records or tapes can refresh your memory of songs that you used to identify during the previous year but which, after a winter, are a slightly rusty memory.
I also need to write down from time to time a description of the calls or songs. However, as the voice production of a bird is so very different from our own, the phonetic alphabet we use is only of limited use for this purpose. The specialist in bird song plays his recordings through a piece of special equipment which allows a sound spectogram or sonagram to be produced. These are graphs which show the length of time the call has taken, the tone, the pitch and to some extent the loudness of the call. Although the sonagram will only give you an approximate idea of the sound it can tell experts more about bird song than any other method.
Usually the average birdwatcher who wishes to remind himself or tell someone else what the voice of some bird sounded like has to rely upon a system which tries to link bird sound to some form of phonetic alphabet. Although several attempts have been made to produce a suitable phonetic alphabet none has been satisfactory so far. The task is made difficult by the variety of ways in which birds produce sounds and also by the varying abilities of the listener to hear and record the sounds. These problems are discussed more fully by E. M. Nicholson in an essay on ‘Voice’ in the new Handbook of the Birds of Europe, the Middle East and North Africa. Whilst pointing out the pitfalls and lack of detailed research into this problem he points out that the vowel sounds used in Pitman’s shorthand, provides a simple but functional system. In her excellent book, Bird Sounds and their Meaning, Rosemary Jellis also emphasises how necessary it is to have a system of sound notation for learning new songs and calls. She gives various guidelines to help construct such a system. For example symbols for ‘non-musical’ elements and rhythmic patterns are suggested, I.e. a vertical line, as on a sonagram, represents a ‘click’ and an ‘X’ represents a single noisy or harsh element in the song or call. Musical notation is adopted to denote rhythm. Anyone who is interested in this field should read both this book and E.M. Nicholson’s essay in the Handbook.
Some noises produced by birds are not vocalizations at all, for instance, the drumming of the Great and Lesser Spotted Woodpecker when they hammer with their bills on an especially selected piece of a tree, or the drumming of a Snipe as it flies over its breeding habitat, climbing and diving with its tail fanned in such a way that the air rushes past the outer tail feather to produce the bleating sound. In spring the Lapwing when flying over its territory, can, with an especially hard downward thrust of its wings, which forces the air through the wing feathers, create a regular low-pitched vibrant sound. The ‘wing-music’ of the Mute Swan is well known to all who have been standing round the edge of a lake as a pair has flown past.
The sounds of birds are immensely varied and describing them adequately is a problem. Some like Chiffchaffs, the tits, Yellowhammers and so on, have phrases for which it is relatively simple to produce an alliteration. Others like Blackbirds, Skylarks and warblers, have songs which we now know from the sound spectogram are composed of a series of phrases which may be put together by the singer as it pleases. Other ‘songs’ are so explosive or gutteral that it is virtually impossible to reproduce them in a written form.