Species Update
While the Sky Lark’s world population is strong, its UK decline continues at a worrying pace
The common Sky Lark is in trouble, says Kate Risely
BIRD MIGRATION IS an amazing natural phenomenon, and, at this time of year, signs of movement are all around us. Some of these are clear, such as the first Redwings arriving for the winter, but others are more subtle, such as the increased visibility of Sky Larks as they start to shift from their breeding to wintering areas. While Sky Larks are common and widespread throughout the UK in both summer and winter, the Birdtrack reporting rate graph shows that they are far more noticeable at certain times of year. One of these times, of course, is the height of the breeding season, when they draw attention to themselves with cascading songs. In August and September, we notice them much less, as they stop singing and go to ground. In October, however, they appear again, both in the skies and in our records, because they are on the move. Sky Larks are naturally birds of steppe grasslands, and over thousands of years their populations have tracked the spread of arable and low-intensity pastoral farming. In Britain and Ireland they are mostly found in lowland farmland, particularly in eastern England, as well as on the hills of England and Wales, and along the western coastal fringes of Scotland and Ireland. In the winter, they retreat from the less hospitable upland habitats, concentrating in lowland eastern areas of Britain, and these movements are what we see in the autumn. In northern and eastern parts of their world range, in Scandinavia and Russia, they are wholly migratory, moving to southern Europe in winter, and large numbers are recorded at our coastal watch points in autumn, indicating that continental birds are passing through. It seems likely that some of our British birds also join these migrants, but here our knowledge is somewhat sparse. While tracking technologies are allowing us to discover more about the detailed movements of some at-risk species, most of our general knowledge of bird movements comes from decades of bird ringing. Despite being a common species, relatively few Sky Larks are ringed, normally a few hundred a year, and of these few are ever recovered, as they do not closely associate with humans. Only 15 Sky Larks ringed abroad have been found in Britain and Ireland, and 13 British-ringed individuals have been recovered abroad. These recoveries indicate that Sky Larks come here via the North Sea coasts of Belgium, Germany and the Netherlands, and some go south to France and Iberia, but they do not give us any idea of the scale of international movements by British birds. Though the world Sky Lark population is very large, and is thought to be secure, declines have been recorded across much of Europe, and here in the UK we have lost more than half our breeding population over 40 years, according to volunteer monitoring schemes. These declines have been linked to agricultural intensification, in particular the decline of spring cereals and cereal stubble, and increases in winter cereals, oilseed rape and intensively managed or grazed grass; changes that are thought to affect their nesting success. It’s also likely that the shift to winter cereals has affected winter survival of Sky Larks by reducing the amount of seed-rich stubble available. The latest completed figures from the Breeding Bird Survey show that these declines are ongoing, meaning that the long-term future looks bleak for the birds we see searching for a winter refuge.
Declines have been recorded across much of Europe, and here in the UK we have lost more than half our breeding population over the last 40 years