Sir: The feral pigeon ("London's pigeon problems come home to roost", 17 September) is no more hazardous to man than any other animal species and is safer than most.
Whatever pathogen the feral pigeon may carry can be carried by all bird species (wild and domestic) and, in the case of some pathogens, by mammals (including farm animals and pets).
Transmission of pathogens from animals to man is in any case exceedingly rare; in the case of the ordinary feral pigeon in a public place and of the ordinary member of the public, there is no hard evidence of there having been such transmission.
Increasingly, research is showing that interaction with animals is in fact highly beneficial to human emotional and physical health, and on this basis animals are being introduced into some hospitals.
On the other hand, evidence of pathogen transmission from the food we buy and from fellow human beings is overwhelming.
Pigeon droppings are chemically incapable of corroding anything. They are safer to buildings and metal structures than ordinary rainfall - let alone acid rain, which is destroying Britain's buildings and can damage metal. Britain is one of the largest exporters in the world of acid rain.
If unculled, pigeon populations stabilise in function of their food base and have low reproduction rates. Only a minority of pigeons attempts to breed. The larger the pigeon flock, the lower the reproduction rate is.
Research also shows that culling would lead to high population regeneration rates, with pigeons immigrating from elsewhere and a fall in natural mortality rates. Besides, under European and UK law, priority should be given to non-lethal management methods.
Pigeon numbers are invariably overestimated. The cost of cleaning Trafalgar Square includes the man-hours for removing human litter, which far exceed the man-hours for washing away droppings.
DR J CUTHBERT