Birds

Bitterns are booming, both literally and metaphorically. These handsome brown birds from the heron family make a noise quite unlike anything else in Britain and we are lucky to be able to hear it. If there is such a thing as a birding bucket list then hearing a bittern’s ‘boom’ — the loudest bird call in the country — should be on it. Before the bittern starts booming he performs a warm-up ritual called grunting. He strengthens his throat muscles, which expand to turn his gullet into an echo chamber. His powerful muscles make up a fifth of his body weight and can propel the sound of his boom for more than three miles.

China has peaked Sir: Niall Ferguson makes some good points about the nature of Xi Jinping’s imperial aspirations but misses two important parts of the picture (‘The China model’, 8 May). First, the Chinese Academy of Science predicts that China’s population will peak at 1.4 billion in 2029, drop to 1.36 billion by 2050, and shrink to as few as 1.17 billion people by 2065. They even forecast that China’s population might be reduced by about 50 per cent by the turn of the next century. And second, China’s economic rise is stalling.

St Tiburtius’ Day, on 14 April, is traditionally when you will hear the first cuckoo. Since at least the Middle Ages, cuckoos have been seen as heralds of spring. They are also often associated with romance, and yet they are some of the cruellest birds found in Britain. The adults arrive in this country at the end of March or the beginning of April and depart in late July or August. They return to central Africa and fly, either via Italy, resting near the River Po and continuing over the Sahara, or stopping in Spain before entering Africa from the far western end. They live mainly in and around the Congo rainforest and in similar habitats as far south as Angola. They come to Britain merely to mate.

My tawny owl has been self-isolating. I say mine but in truth she chose the nest box in my neighbour’s garden rather than the one I almost killed myself to install, balancing it on my head as I scaled a rickety old ladder. A couple of months ago I spotted the owl, happily sitting in the box’s entrance in the weakening sun. A pattern was established. Every evening as day drained away, I went into the garden, balancing my old Zeiss binoculars alongside a glass of white. The owl would fly in silently from the south, sit around for a while and then disappear into the box. These regular sightings stopped six weeks ago, and I have been worried since. But early this morning I saw her again.