Conservation of Zino's petrel Pterodroma madeira in the archipelago of Madeira Francis Zino, Paulo Oliveira, Susan King, Alan Buckle, Manuel Biscoito, H. Costa Neves and Amilcar Vasconcelos Abstract Birds restricted to islands are susceptible to extinction, and burrow or ground-nesting birds are particularly vulnerable to introduced mammalian pred- ators. 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 ®rst 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 ¯edged. 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 conserva- tion strategy for the future is suggested. Keywords conservation, control, introduced species, Zino's petrel. Introduction Birds restricted to islands are susceptible to extinction and feature prominently in the list of the world's most threatened species (Quammen, 1997; Grant, 1998). Bur- row or ground-nesting seabirds such as Pterodroma species are particularly vulnerable to introduced mam- malian predators (Bertram & Nagorsen, 1995), and 19 are described as globally endangered (Collar et al., 1994). Zino's petrel or Madeira freira Pterodroma madeira (Plate 1) (Mathews, 1934a) is no exception. This burrow- nesting seabird, endemic to the island of Madeira, is listed as `Endangered' (Collar & Stuart, 1985; Groom- bridge, 1993) and classi®ed as `Critical' by Collar et al. (1994). In addition it is included in Annex I of the EU Wild Birds Directive (79/409/CEE). The present estimate for the breeding population of Zino's petrel is between 30 and 40 breeding pairs, with a breeding area restricted to the central mountains of Madeira (Zino & Zino, 1986; Zino & Biscoito, 1994; Zino et al., 1994). This gad¯y petrel is a colonial species and, in the prebreeding season, carries out nocturnal ¯ights above the nesting grounds during which it emits characteristic ¯ight calls. Breeding occurs between March and October in burrows on cliff ledges where the vegetation is unaffected by grazing. Currently, ®ve breeding ledges are known. The species' present con- servation status is attributed to predation by introduced mammals, namely black rats Rattus rattus and feral cats Felis catus and the loss of habitat mostly as a result of overgrazing (Zino et al., 1996). Zino's petrel was ®rst recorded in Madeira in 1903 (Schmitz, 1905). At the time it was thought to be Fea's petrel Pterodroma (Oestrelata) feae, a species described from the Cape Verde Islands (Salvadori, 1899) that also breeds on the island of Bugio (Desertas), neighbouring Madeira. It is of interest to note that there are two skins of Pterodroma feae at the Cambridge Museum, collected by Frere off Madeira as early as 1853, which remain undescribed. In 1934, Mathews suggested that the Pterodromas of Madeira and Bugio be considered as sub- species of Pterodroma mollis and be called P. m. madeira and P. m. deserta, respectively (Mathews, 1934a,b). Twenty years later, Bourne (1955) speculated that F. Zino (corresponding author) Freira Conservation Project, Rua Dr. Pita 7, 9000 Funchal, Madeira. E-mail: nop11015@mail.telepac.pt P. Oliveira, H. Costa Neves and A. Vasconcelos Parque Natural da Madeira, Quinta do Bom Sucesso, Jardim Botanico, 9050 Funchal Madeira. S. King Department of Biological Sciences, Manchester Metropolitan University, M1 5GD, UK. A. Buckle Syngenta AG, Fernhurst, Hazlemere, Surrey GU27 3JE, UK. E-mail: alan.buckle@syngenta.com M. Biscoito Museu Municipal do Funchal (Historia Natural), Madeira. E-mail: manuel.biscoito@mail.cm-funchal.pt Revised manuscript accepted for publication 20 December 2000 128 Oryx Vol 35 No 2 April 2001 Ó 2001 FFI, Oryx, 35(2), 128±136