Seventy years ago the population of Southern Rhodesia was only about 500,000. The inhabitants occupied the land according to their tribal customs, and were mainly hunters and pastoralists. In those days the whole country abounded with wild life. Then western civilization came to the country, bringing with it advanced agricultural techniques, medical science and the western system of law. Within thirty years vast changes and development took place. The indigenous population trebled: industries, particularly mining, sprang up all over the country and around these industries towns were built with the resultant network of road and rail communications. But, following the pattern of development seen in so many countries, Rhodesia's natural resources were being squandered and destroyed, in some cases through lack of knowledge, in others wantonly. Nevertheless, even in the 1920's a few people, supported by the Government, did make some provision for the conservation of wild life and in 1927 the first game reserve was established at Wankie. By the 1930's, however, it was obvious that other resources, particularly the soil, were being lost at an alarming rate. Again a few far-sighted people, led by Water Court Judge Mcllwaine, stirred up public opinion, the Governor appointing a commission of enquiry into the extent to which the natural resources were being squandered. The outcome of this enquiry was the establishment of the Natural Resources Board, constituted by Act of Parliament which, in essence, recognized the Board as the public trustee for the natural resources of the country. The Board has extremely wide powers and can give orders to the owners, occupiers or users of any land to adopt such measures as it may deem necessary for the conservation and protection of the resources. Whilst an appeal to the court against such orders is provided for, the Board relies upon persuasion rather than compulsion and depends upon the goodwill and common-sense of the people to ensure a future both for themselves and for those who are to follow.

The largest colony of Cory's shearwater Calonectris borealis nests on the island of Selvagem Grande in the north-eastern Atlantic. In 2002, a programme of eradication was conducted to remove two alien invasive mammals, the house mouse Mus musculus and European rabbit Oryctolagus cuniculus. Preliminary studies recorded beneficial effects of the eradications for a variety of plant and animal species, including Cory's shearwater. We recorded fledging rates of shearwaters for 1982–2001, prior to the eradication, and for 2002–2020, after the eradication, from two quadrats, each containing 134–329 nest sites. Although there was annual fluctuation in fledging rates in the quadrats, the mean rate of 40.74 ±SD 3.92 fledglings per 100 nest sites for the two quadrats combined prior to the eradication of mammals increased significantly, to 52.88 ± SD 5.03 per 100 nest sites, after the eradications. Because the two mammals were removed synchronously it is difficult to know which factors depressed fledging of Cory's shearwaters on Selvagem Grande. However, the predatory behaviour of house mice on other oceanic islands, and the fact that increased fledging was seen soon after the eradications occurred, suggest predation by house mice on shearwater hatchlings was the main cause of losses.