The joy of ….. birdsong
In 2015 the Robin was voted as Britain’s national bird. Robins sing their wistful song from late summer/autumn (July/August) all through winter and into spring. The autumn song is a much less rich and softer sound than that sung in spring. Although other birds may sing occasionally in autumn, Robins are the only species which sing consistently. Males and females each set up separate territories in winter, when both of the sexes sing. However, females stop singing as soon as they are paired with a male. In suburban areas with street lighting Robins may sing regularly at night and may even feed their young by streetlight!
A recent study of birdsong in South Devon found that only three species sang in every month, namely Woodpigeon, Collared Dove and Robin. The first two have very extended breeding seasons, occasionally even nesting in winter; a Collared Dove, shown on ‘Spotlight’, was filmed sitting on a nest in December! Most birds resident in the UK (as opposed to migrants) start singing in January or February.
The reason why male birds sing is twofold – to advertise their territories to other males, and to attract a female. Singing in birds has been linked with levels of the hormone testosterone; increasing daylight in late winter/spring triggers a rise in levels of testosterone and causes birds to start to sing regularly.
Now that winter is nearly over we can hopefully look forward to that glory of the temperate zone spring, the dawn chorus. If you have never made a special effort to get up very early, even before dawn, to visit nearby woodland – such as that around Burrator Reservoir – and hear the birdsong, I urge you to try it at least once. The Robin is often one of the earliest songsters, well before first light, together with Song Thrush and Blackbird; then one by one other species start to sing, until the woodland echoes to the rich sound of both resident and migrant songbirds. Some birds sing different variations of their song, similar to dialects, in different parts of their range; for instance, Chaffinches have slightly different songs in Devon, Scotland and Germany.
If you wish to learn more about song, recordings of birdsong can be found on inexpensive CDs, or on the RSPB ( www.rspb.org.uk ) or BTO ( www.bto.org ) websites. However, there is no better way than going out into the garden in late winter or spring and listening to the garden songsters. Not only is it free, but it will lift your spirits!
A report published by the charity Butterfly Conservation last year, The state of the UK’s butterflies 2015, showed that over half of Britain’s butterflies, some of them previously common and widespread, have declined by over 50%. Volunteers across the country have been counting butterflies annually since at least the 1970s and the results indicated a very worrying decline in many species. In contrast, the distributions of a few species, such as the Ringlet, Orange-tip, Comma and Speckled Wood, have expanded northwards dramatically, perhaps due to climate change.