Skylarks need short vegetation in spring for their nesting areas. Spring-sown barley or wheat were ideal, but there's been a big move towards crops sown in autumn instead. By the time the larks' breeding season arrives, the crops are too high. That's been a huge problem for skylarks. Round here they do well in old pasture, meadows (what's left of them) and to a lesser extent in leys. Like many songbirds they are in trouble because of modern farming practices. In the next few years I think we are going to see a big revolt against neonicotinoid insecticides. I don't think it's an exaggeration to say that they are a significant threat to both the natural world and to the future security of our food supplies.