THE peregrine falcon, the fastest bird on earth, continued to increase its numbers in northern England last year, according to recently published statistics.

The peregrines' success story is remarkable because, by 1961, they almost became extinct nationwide, the victim of pesticides introduced after 1948.

When the first British Trust for Ornithology (BTO) survey was conducted in 1961, peregrines were found to have all but disappeared from southern England and were severely reduced throughout northern England, Wales, Northern Ireland and southern Scotland.

However, once the pesticides were banned four decades ago, peregrine numbers increased, and the latest survey showed there were 1,402 breeding pairs last year, compared with 1,283 in 1991, and 874 in the 1930s, before the population crashed. Of the 2002 pairs, 55 were in the North-East and the Pennines.

The figures mean the national population increased by nine per cent between 1991 and last year, and by 60 per cent since the 1930s.

A spokesman for the BTO said northern England was one of the areas seeing an increase, adding that one of the reasons was that the birds were nesting in quarries and tall buildings.

But it is not all good news. Whereas the bird has done well in most areas, there has been a 15 per cent decline in north Wales and 12 per cent in Northern Ireland, which has been blamed on food shortages, marine pollution and persecution.

Anecdotal evidence suggests that peregrines have bred poorly this year in parts of the Yorkshire Dales and Cumbria, from which many North-East peregrines migrate in search of territories.