Failure of Myxomatosis on Skokholm Island

Abstract

ATTEMPTS to exterminate the wild rabbits on the Pembrokeshire island of Skokholm by various methods were described in Nature ¹ in 1940. The late Sir Charles Martin brought the virulent strain B of the virus known as Myxomatosis cuniculi Sanarelli 1898 to the island in three separate attempts to induce myxomatosis in rabbits in 1936, 1937 and 1938. In each attempt the marked rabbits (inoculated with the virus) appeared to have died within the usual period of less than fourteen days; but there was little or no spread to uninoculated rabbits. At the time, the apparent failure of this virus to spread in the dense colony of rabbits on Skokholm seemed inexplicable, since the same strain had wiped out rabbits in Sir Charles Martin's enclosures (500 sq. yd.) at Cambridge in 1934–35². It is significant that before conducting these controlled experiments in the field in Cambridgeshire, Sir Charles had evidently decided that the possibility of the virus being carried to wild rabbits elsewhere by insects was too remote to constitute a public danger—a risk that would not be lightly undertaken by scientists to-day. Sir Charles believed that the disease was chiefly propagated by direct contact. We now know that contact alone is not effective, and the virus must enter the tissue of a healthy rabbit through a scratch, cut or insect bite.