Shamrock is a great diet boost for birds

THE pasture field outside my study window has become a parade ground for birds. 

First a squad of about a dozen jackdaws marched across from left to right, then seven wood pigeons counter-marched from right to left, finally a pair of magpies joined in. All moved at a steady pace, pecking at the ground as they went. I know what they were doing.

It’s an old pasture, relatively ‘unimproved’, and quite species-rich. Among the plants that grow there are several kinds of clover and in March these are shooting up new leaves that are juicy and nutritious. The birds were packing their crops with these leaves and getting a boost of vitamins and minerals after a long winter with a shortage of greens in their diet.

The word shamrock comes from the Irish seamrog which means young clover. The birds were eating shamrock. Of course there has been a long-running debate about the precise botanical identification of shamrock. In 1988 Dr Charles Nelson, who was then director of the Botanic Gardens in Glasnevin, invited people from all over Ireland to send him samples of ‘true’ shamrock. He then grew the samples on until they flowered and he could identify them accurately. He got over two hundred samples and ended up with about half a dozen different species. Roughly half the samples turned out to be Trifolium dubium or lesser clover. About another third were Trifolium repens, or white clover. I prefer the definition used by the birds — shamrock is the new, spring growth, the Irish ‘young clover’, of any species in this family.

Watching the birds feeding vigorously I realised that it was really an ideal plant to associate with a spring festival like Saint Patrick’s Day. I certainly think its significance pre-dates Saint Patrick and his attempt to explain the Holy Trinity to a group of fifth century druids. Those druids already believed that the number three had special powers and they worshipped a tri-partite pagan deity. What’s even more significant is that they were descended from over a hundred generations of dairy farmers.

Neolithic dairy farmers may not have known that clover can improve pasture by fixing atmospheric nitrogen. But they certainly did know that the growth of clover in the spring was vital to the well-being of their cattle and the production of rich milk. When it came to the power of the shamrock Saint Patrick was preaching to the converted.

And the emergence of young clover in March is not just important to farmers and their livestock. There were three species of wild bird grazing outside my window. I knew that when darkness fell they would be replaced by rabbits and hares. I wonder if Barack Obama will appreciate all this when he gets his bowl of shamrock in the White House.