This patch of mud is out of place in the immaculate farmyard, but it’s deliberate. After a desiccatingly dry spring, the swallows need soft mud to build their nests. Slippery-sleek glossy darts, they flash down and fill their beaks. This year, Dad is experimenting with “double roofing” to help the swallow chicks. When a new roof was needed for a stable block, the replacement was fitted directly on top of the old one like a second skin. The sparrows already love it, flitting in the gap between the two. It should prevent the chicks overheating as they often do under corrugated iron roofs – when temperatures hit the 30s, the young have no choice but to bail out of their sauna nests, falling to the ground. With gaping yellow beaks, sometimes sightless, pink and barely feathered, they are helpless and vulnerable to predators or being trodden on by a horse. Sadly, not everyone welcomes our summer migrants, with retailers, councils and property developers often determined to keep them out. Three years ago, we fought our nearby Tesco supermarket until it allowed swallows to nest at their usual position. Happily, it has welcomed them ever since, with nest cups and signs explaining to customers. But it’s clearly not a company-wide approach. Last month, heavy with deja vu, I learned that once again a Tesco store had put nets up. While the house martins were making that formidable flight from sub-Saharan Africa, local people swung into action, and a petition reached 50,000 signatories. The nets were removed just in time for the return of these red-listed birds. And it isn’t just companies taking this legal but disgustingly immoral approach. Nearby, a gorgeous cart lodge, busy with swallows last year, has had secure garage doors fitted. Another site gone. I feel sick to think about it. Active nests cannot legally be disturbed, and of course summer migrants leave, but they remain site-loyal. Often, there just aren’t any suitable alternatives if they are faced with nets or doors. Our heralds of summer continue to decline. Each year, the swallows fill me with joy as I wonder at their beauty and almost impossible acrobatic elegance. We must do more.