Meditation on the Problems of bird population

That bird numbers fluctuate will be apparent to all who watch birds from year to year, and the lifetime of any one of us will see one species increase while another declines in certain areas even to the point of extinction. As we learn to meditate and explore meditation, we discover that such fluctuations may be temporary or permanent according to the true cause of the variation. During the present century, the corncrake has decreased to a striking degree over most of England, so that in places where, at the beginning of the century, it was common, it is now extremely rare or even quite absent. Investigations have suggested that this decrease is associated with a change in methods of agriculture. Modern mechanized reapers together with the introduction of quickly maturing grasses, have advanced the average time of the hay-harvest by as much as three weeks, so that the corncrake, which nests in and around fields of mowing grass, has no time to get its brood off before the fields are cut. This is but one example of a serious decrease in the population of a single species of bird in comparatively recent times. The kite, which formerly swarmed over the towns of mediaeval England and acted as scavenger in the garbage-filled streets has been reduced by modern sanitation and persecution to an artificially upheld remnant in the Welsh hills. On the other hand we have witnessed some striking increases among certain species. The starling is undoubtedly a much commoner bird than it was two hundred years ago. Gilbert White mentions it but twice in the whole of Selborne. The fulmar petrel has spread in an amazing way in recent years. Its old stronghold was the rocky islands of St. Kilda where it was noted as breeding in 1697. In 1878 it first appeared on the island of Foula, off northwest Scotland, and since then has spread practically all round the coast of Great Britain and Ireland and has even reached the Scillies. The redshank has increased.....