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The largest colony of Cory's shearwaterCalonectris borealisnests 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 mouseMus musculusand European rabbitOryctolagus 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.

Anticoagulant resistance has been present in Norway rats (Rattus norvegicus) in Hampshire and Berkshire for forty years. All first-generation anticoagulants and two of the second generation, bromadiolone and difenacoum, are resisted by rats carrying the L120Q single nucleotide polymorphism (SNP). A regulatory restriction on the use of resistance-breakers brodifacoum, difethialone and flocoumafen in the UK effectively prevented their use against Norway rats for more than 30 years. During this time, L120Q spread from original localised foci eventually to cover most of central-southern England; with other more dispersed foci elsewhere in the UK. We summarise research on L120Q Norway rats and the field performance of anticoagulant baits against them. Bromadiolone (50 ppm), difenacoum (50 ppm) and brodifacoum (23 ppm) baits were each applied on two farmsteads where it had been established that Norway rats carried the L120Q SNP. Preliminary DNA resistance tests conducted at the farms found only one of 107 rats to be susceptible and 86.9% to be homozygous resistant. The bromadiolone and difenacoum applications were either partially or wholly ineffective; brodifacoum treatments were fully effective. Quantities of active substances used varied between farms and substances; but more bromadiolone and difenacoum baits were applied than brodifacoum baits during the treatments. Results confirm the high incidence of resistance and support advice that bromadiolone and difenacoum should not be used against the L120Q SNP. Prolonged use of resisted anticoagulants has resulted in a high prevalence of homozygosity and resistance spread. Failed treatments result in prolonged feeding on anticoagulant bait and leave Norway rats alive carrying, presumably, high residues. It remains to be seen whether the use of now-permitted effective substances, and the introduction of a rodenticide stewardship regime, will curtail the spread of resistance and reduce anticoagulant residues in wildlife.

The Portuguese island of Selvagem Grande (Great Salvage) in Macaronesia is an important seabird breeding station in the eastern Atlantic. Significant populations of Cory's shearwater Calonectris diomedea (Scopoli, 1769), Bulwer's petrel Bulweria bulweria (Jardine & Selby, 1828) and little shearwater Puffinus assimilis baroli (Bonaparte, 1857) are present, and white-faced storm-petrel Pelagodroma marina (Latham, 1790) and Madeiran storm-petrel Oceanodroma castro (Harcourt, 1851) populations are of global significance. Selvagem Grande also provides diverse habitats for an extensive flora, including 11 endemic species. The 270-ha island was also inhabited by two alien invasive mammals: the European rabbit Oryctolagus cuniculus (Linnaeus, 1758) and the house mouse Mus musculus (Linnaeus, 1758). Both are known to have had adverse impacts on breeding seabirds and island vegetation. In 2002, the Natural Park of Madeira conducted a program using brodifacoum bait formulations aimed at rabbit and mouse eradication. Approximately 17 000 individual baiting points were established on a 12.5 × 12.5 m grid. Baits were also applied by hand "seeding" on steep slopes and cliffs where bait stations could not be placed. Rabbits were removed after a month. However, mice persisted for considerably longer and strategic bait applications against them continued for a further six months. Subsequent assessments by trapping, bait takes and systematic observation of signs over three years, has confirmed the removal of both alien invasive species. This paper presents information on these operations, on measures adopted to mitigate adverse impacts of the eradication program on important vertebrate non-target species, including Berthelot's pipit Anthus berthelotii Bolle, 1862 and a species of gecko Tarentola bischoffi Joger, 1984 and on the initial response of the island's ecosystem to the eradication of rabbits and mice.

Birds restricted to islands are susceptible to extinction, and burrow or ground-nesting birds are particularly vulnerable to introduced mammalian predators. Human intervention has also played a vital part. Birds have been used as a source of food, and in more recent times the rarer species have suffered from specimen and egg collection. The island of Madeira and its resident species, which include the endemic Zino's petrel or Madeira freira Pterodroma madeira, are no exception. From subfossil evidence, this bird was once abundant. It was first recorded in 1903, and was already limited to the high central mountain massif of Madeira. By the middle of the century it was considered extinct, but a relict population was rediscovered in 1969. By 1985, all known breeding attempts were disrupted by introduced rats, to the extent that no young fledged. In 1986 the Freira Conservation Project was founded with the aim of increasing the population of Zino's petrel, by controlling rats and human interference, the principal perceived threats to the species. This control was extended to cats after the disaster of 1991, in which a cat(s) managed to get onto one of the breeding ledges and kill 10 adult birds. The results of these efforts have been positive and the small colony is making a slow, but steady recovery. To maintain this success, a conservation strategy for the future is suggested.