03-May London’s Woodland Songbook

It is the loudness and richness of the song, its wavy outline and peppering of fine, clear notes that give it away. The song of the garden warbler in contrast is more of a random warble without the wavy outline and with no clear notes. It is always vigorously delivered for much longer than the blackcap’s, perhaps for up to a minute in length. There are no harsh notes, and it can seem more scratchy than the blackcap’s. Where there are patches of dense woodland near water, as along the Lee Valley, the blackcap may be heard, sometimes duetting with nightingales.

Chiffchaffs are commonly heard in May, but now they may be joined by willow warblers. For many, the birds look identical, only being separated by song. The willow warbler tends to be slightly brighter in colour, with paler legs and a more prominent eye stripe. Its song is variously described as a ‘descending cadence’ or ‘liquid arpeggio going down the scale’. A trickle of descending notes with a disappointing ending is a less romantic but equally useful description.

The first half of May is probably the best time to listen to the surprisingly extensive range of calls made by great tits. Of the fifty or more different calls they have many can be confused with the coal tit, marsh tit, chaffinch or even goldcrest. The familiar ‘spring call’ of ‘teacher teacher’ is easy enough, but there are other two syllable calls such as ‘tis-so, tis-so’ with slightly different emphases.

It can also be sung much more softly and more rapidly than usual. There is also a metallic ‘ping ping’ and almost human ‘coo-ee coo-ee’ as well as a whole series of three syllable calls. Some of these have an accent on the first syllable e.g. ‘see-b-but’ and some on the second syllable e.g. ‘b-but-see’. Sometimes both a two syllable and three syllable call are run together. Then there are even more complicated deliveries of several notes in ringing succession e.g. a repeated ‘tl-ee, tl-ee, tl-ee, tl-ee’ or a mixture of notes with a slurred ending e.g. ‘ping, ping-zhee-zh-zh-zh-zh’. On top of all this there are also local variations, with birds using some calls in preference to others. Then there are the rapidly repeated bell-like calls as well as a whispered private song when the male is in the presence of a female. After attempting to decipher some of these you may even be rewarded with a snake-like sharp hiss if you get too close to a brooding female.

Two other birds recently arrived from Africa but now rarely heard are the redstart and the wood warbler. The redstart likes old parks with mature trees or rows of willows bordering a river. It has an unremarkable jolly song lasting between one and five seconds, delivered perhaps five or six times a minute at most. It is the short, abrupt ending that usually gives it away. Its even rarer relation, the black redstart, prefers stony, derelict areas where it delivers a grating warble. The wood warbler is worth seeking out for its famous long high-pitched ‘shivering trill’. It has been described as ‘a spinning coin which eventually settles’ or ‘a descending silver shiver’. This highly memorable song is often delivered in grand groves of mature beech trees. Luckily, the bird prefers to sing from the lower branches. Although by no means assured of success, Dagenham Chase is worth visiting for redstarts and Hainault Forest for wood warblers. Wherever there are large amounts of concrete rubble and deserted buildings it is also worth listening out for black redstarts. Other songs of note to listen out for in woods this month are the delicate calls of long-tailed tits as well as chaffinches and goldcrest if visiting pine woods.