Before my month-long watch of the mallard nesting in my garden, I hadn’t appreciated the feat of endurance it takes for a duck to incubate eggs. The mallard I wrote about last month laid more than half her own body weight in eggs over 10 days in the flower bed outside my window. She then spent 31 days sitting on the nest with just two hours’ break a day.

These were long, hot days with little chance to drink, feed or poo. Before flying off, she tugged moss or grass over the eggs. What had seemed an open place to nest became camouflaged by leaf patterns as plants grew. Unlike the secretive woodcock that nested in this same border two years ago, her wings clattered as she took off.

Her initial wariness of our movements gave way to indifference – when I walked past with a watering can or deadheaded nearby daffodils, she carried on preening, plucking breast down or tucking her head under her wing. She tired as the days lengthened. Her back rose and fell with breaths as she dozed, one eye open, the other closed in unihemispheric sleep; half her brain slept while the other half stayed alert to predators. Once a stoat ran through the garden and I worried for her.

Hatching seemed near when she increased in restlessness, constantly turning eggs to the heat of her brood patch, its skin naked of feathers. Then, at 1pm, I saw the first duckling, all mottled soft feathers and miniature beak. The eggs, though laid over several days, hatched within 20 hours, the mound of her back looking ever more plump as her wings sheltered a growing number of silent ducklings.

I knew that the passage to the river might be difficult and had a bucket ready. She led her bustling brood to the garden wall, drawn by the sound of water. As she scrabbled on the coping stones – looking very thin – the ducklings couldn’t follow. I scooped them into the bucket, and passed it over the wall to my husband who released them. We watched as 10 ducklings swam after their mother down the sunlit River Allen.