Details of this species in Stewart Is.
Source: Harper and Dobbins, 2002
Species Notes for this Location:
Research suggests that F. catus are not present year round in sub-alpine scrub, but stray into this habitat and above the bushline during summer when rat abundance is low. Rats are the principal prey on Stewart Island for F. catus, and little alternative prey is available during summer. Introduced rats make up 93% of the diet of cats on Stewart Island (Zavaleta et al., 2001; in: Zavaleta, 2002).
Management Notes for this Location:
A cat control programme began in 1992, initiated to halt the decline of the southern subspecies of New Zealand dotterel (see Charadrius obscurus in IUCN Red List of Threatened Species ), which was attributed primarily to predation by F. catus. A perimeter of bait stations was set up around the bushline, and poison baits were set during spring and summer, when the dotterels were nesting. Dotterel numbers had expanded from 65 to 170 individuals by 2000. Further research into the habitat preference of F. catus is continuing in order to achieve a more efficient use of resources for ongoing control of feral cats.
Reduction in native biodiversity: At least five species of bird have disappeared from the island, in part due to the predatory impact of cats: the South Island kokako (Caiiaeas cinerea cinerea), Stead's bush wren (see Xenicus longipes in the IUCN Red List of Threatened Species), the Stewart Island snipe (Coenocorypha aucklandica iredalei), the South Island saddleback (see Philesturnus carunculatus in the IUCN Red List of Threatened Species) and the yellowhead (Mohoua orchrocephala). A sixth species, the brown teal (Anas aucklandica chlorotis), has not been seen since 1972. A seventh species, the kakapo (Strigops habroptilus), was rediscovered in 1977 in a small area of about 10 000ha(King, 1984). Kakapo are an unimportant component of the diet of feral cats and occur in only -5% of cat scats. However, the impact on kakapo is severe. Between 1980 and 1982 about 60% of male birds were killed by cats. Between the 1981-82 season and late 1983 the population was estimated to have declined from 50-150 to just 20 birds (King 1984, in Dickman 1996). Cats also prey on parakeets (Cyanoramphus spp.), pipits (Anthus novaeseelandiae), blue penguins (Eudyptes minor) and Fiorldland crested penguins (see Eudyptes pachyrhynchus in the IUCN Red List of Threatened Species).
Threat to endangered species: A continuing decline in population size of the New Zealand dotterel (see Charadrius obscurus in the IUCN Red List of Threatened Species) on Stewart Island has also been attributed to predation from feral cats; the island population now numbers only 60-65 birds and is considered endangered (Dowding and Murphy 1993 in Dickman 1996).
Last Modified: 16/02/2005 8:32:20 a.m.