Skylark populations are declining in almost all countries of northern and western Europe.
In the UK, the population halved during the 1990s, and is still declining. In the preferred habitat of farmland, skylarks declined by 75% between 1972 and 1996.
The main cause of this decline is considered to be the widespread switch from spring to autumn-sown cereals, which has resulted in a dramatic reduction in the number of chicks raised each year.
Autumn-sown cereals are taller and denser throughout the season. Fewer birds nest there, and those that do are unable to raise as many broods as birds in spring-sown crops. Many nesting attempts are on or close to tramlines (tractor tracks that are used to apply the many sprays to the crop), which makes the nests vulnerable to ground predators.
Winter food supply is also scarce in the absence of stubbles, which are favourite feeding places. Increased use of insecticides and weedkillers are likely to remove an important part of the food source.
In grassland habitats intensification has also been detrimental. Increased stocking densities on grazing land have made the grass too short for skylarks, and increased the risk of nests being trampled. A switch from hay to silage has resulted in many nests being destroyed by the cutting machinery, since the period between cuts is often too short for successful nesting.