WOODLARK (Lullula arborea)
The Woodlark is the only species in the genus Lullula, and it is a pretty scarce bird in Switzerland (probably less than 500 pairs), occurring only spasmodically in the central Jura and parts of the Valais. Since it prefers open rough ground at the edge of forest this scarcity is undoubtedly due to habitat destruction for agriculture. The Woodlark population of Europe as a whole underwent a major decline between 1970 and 1990, but seemed to stabilise after that, probably as conservation efforts seem to have met with some success. The total population in Europe (which is 75% of its breeding range) still exceeds 1.3m and so it is not listed as an endangered species, but neither can it be described as a common bird. The Swiss Bird Index shows the population as stable but it is listed as vulnerable on the Swiss Red List.
It is a pity it is not more common because it has a beautiful song. Like the Skylark it nests on the ground and the song is usually delivered in flight, but it may also sing from a tree, or a wire or even a mound on the ground. In song flight it spirals upwards and downwards singing as it moves in circles. The song is a complex series of liquid notes which pour out, each phrase tends to fall slightly in pitch which gives it a rather melancholy feeling. The notes are quite varied but all the books tell us that they match the phrase "lulu" hence the generic name and the name in French, you can decide for yourself how accurate this is. But the song is distinctive.
I have not recorded it in Switzerland, the following piece was taken in Norfolk UK:
As you can hear the song is very liquid and somewhat melancholy, the phrases vary a lot however and to give you an idea I show here two sonograms taken from different sections of that recording.
In this first example you can distinctly see and hear the decline in pitch from about 4 Khz to around 3.2 Khz in the first two phrases, it is a little harder to distinguish in the third where the pattern of notes is more complex:
And in this next example the first phrase is almost flat, the second with a small decline and the third very clearly declines:
All this means is that (as usual) you need to listen carefully to what is going on, But the tone, the fluidity and the aerial delivery mean that you would be unlikely to confuse this with any other species.
SKYLARK (Alauda arvensis)
Alouette des champs
Most people probably hear more than they see the Skylark. On the ground its brown plumage blends with the background, and in the air (where it sings) it soars to great height until it is a tiny dot which pours its liquid song down to the ground below. It is a very evocative sound which inspired many a poet and Shelley wrote the famous "To a Skylark" the first two verses of which describe the song and behaviour well, listen as you read it:
Hail to thee, blithe Spirit!
Bird thou never wert,
That from Heaven, or near it,
Pourest thy full heart
In profuse strains of unpremeditated art.
Higher still and higher
From the earth thou springest
Like a cloud of fire;
The blue deep thou wingest,
And singing still dost soar, and soaring ever singest.
Skylarks evolved to live in open grassland (although now use our artificial version which we call farmland). There being no trees to sit in and sing, yet still needing to broadcast its song, the Sklyark developed an almost vertical song flight where it rises to great height and hovers there high over its territory for up to 15 mins singing its heart out. As you can hear the song simply sounds like a continuous stream of sound because of its rapidity. Studies have shown that the notes can be delivered at a rate of 43 Hz (43 per second) and call phrases at 10 Hz. The current theory is that the bird rapidly fills its lungs between each note and is exhaling to make each sound - quite a feat when you are also flying !!
The complexity of all this can be appreciated if we look at a 6 second sequence:
and is even more impressive if we slow it down to one-fifth the normal speed and then you can follow the pattern with your eyes (NB in slowing down the speed the pitch of the song is lowered by the same amount and so sounds quite strange - but look at the pattern):
But if you listen carefully the sound is not completely random and does have repetitions and patterns in it - listen to this one:
and see the repetition in the middle section of the song:
I once had an interesting incident which demonstrated the determination to sing that this species has. One day I was recording in the Camargue and had focussed on a Skylark singing away on quite a windy day, suddenly it was set upon by a Hobby which dived down on it like a rocket. The Skylark lost its step in its song, and uttered a couple of phrases as it too tumbled down into dense vegetation immediately in front of me to avoid being eaten, but then let go a couple more defiant burst of irrtitation from the protection of a small bush, you can hear this incident starting with the attack at about 7s into this next file and the two angry bursts at 14s and 16s:
In Switzerland it is found up to about 2,400m in summer, but in winter is mostly in the low valleys no higher than 600m. It is generally in decline in Europe due to changes in farming practices where many cereals are now planted in winter which then makes agricultural land less suitable for them in the breeding season as the crops are then mature and cover the ground too densely.